Google Search

Current Weather Condtions By City

New Cities Are Being Added. Please Keep Checking if You Don't See Yours Chicago, Los Angeles, Miami, New York, Philadelphia, Washington, DC

USA Current Weather and Current Radar Maps

Current Watches, Warnings and Advisories for the US Issued by NOAA

Saturday, January 19, 2013

Tornado Outbreaks Then and Now - Apples and Oranges?

Early in my graduate school experience I had the privilege of surveying the damage from many of the April 3-4, 1974 Superoutbreak tornadoes as part of Dr. Fujita's team. 148 tornadoes struck in 48 hours. Six of the tornadoes in that outbreak were rated F5 (on the original Fujita Scale) and 30 were rated F4 or stronger. There were more than 300 fatalities, over 5000 injuries, and the sum of tornado path lengths exceeded 2500 miles. The Superoutbreak has been the benchmark for all tornado outbreaks since.

I always thought that there was a chance that some future tornado outbreak might be worse. The most recent one could be, at least in some respects. Damage surveys are still in progress that will bring us the true count of the number of tornadoes, their EF-Scale ratings, path lengths and widths, and other measures of the outbreak's fury. The National Weather Service, using preliminary data, has already indicated that its tornado count might exceed the number of tornadoes in the Superoutbreak.

Once Doppler radars were deployed across the United States in the early 1990s, though, I never thought I'd see a tornado outbreak kill hundreds of people again. How sad that it has happened on Wednesday. More than 200 people were killed in Alabama alone and more than 300 in total, according to news reports! The Doppler radars allow us to see tornadoes and their parent thunderstorms' rotating updrafts like never before, and the National Weather Service issues tornado warnings with an average of 13 minutes of lead time (in advance of the tornado), and often much more than that. Combine that with so many more - and more efficient - ways of getting the warnings in this internet era and it's a "different world" relative to the 80-character-per-second teletypes that gave warnings to the media (and not directly to the public) back in 1974. People can get timely and effective warnings on NOAA Weather Radio, on The Weather Channel, from services like TWC's "Nofify!" that can personally send you a message that a tornado is coming, and in many other ways.

It's apples versus oranges in the relative ability for people to know a tornado was coming in the two eras. Yet so many died in 2011. That must be a function of the violence of the tornadoes, combined with the fact that so many took aim on communities rather than rural areas. And when tornadoes are violent, even being warned and taking proper safety measures is no guarantee of survival. Finding proper shelter improves your odds, but only being in an underground shelter or specially designed in-home shelter can ensure your survival.

But it's also a "different world" in the way that tornadoes get rated. The mainstay of the original Fujita Scale used to rate tornadoes was that a home crushed into small pieces and blown away would earn an F5 rating, with wind speeds estimated at 261-318 mph. Engineers surveying the tornado damage back in 1974 began to tell meteorologists that it didn't take 300 mph winds to turn homes into piles of rubble and cast the pieces to the wind. Even well constructed concrete block and brick school buildings could fail in 220 mph winds, they said. And homes with damage apparently fitting an F5 description often happened because the house was not properly secured to its foundation in winds less than 150 mph.

In the years since, these engineering analyses began to work their way into damage assessments, and in 2007 an Enhanced Fujita Scale (EF Scale) system was officially implemented. An EF5 tornado has winds estimated as low as 201 mph. And it's difficult to rate a tornado as EF5 based upon it just demolishing a house.

Statistically, the number of tornadoes being rated 2-5 have been decreasing since the 1970s, despite the total number of tornadoes being recorded showing a dramatic increase. This is at least partly a consequence of the introduction of engineering concepts into the rating process. I was part of the team that developed the EF Scale, and it's a system that more accurately estimates tornado wind speeds. But it troubled me then (and still does) that it might be hard to compare past tornado outbreaks with future ones and determine which was worst. It's apples and oranges, to some extent, in the rating systems then and now.

April outbreak versus Superoutbreak?It will be interesting to see just how many tornadoes were in this April's outbreak, and how many get rated EF5. But the death toll, the number of tornadoes in a 24-hour period, and the total path length of the tornadoes may be more appropriate measures by which to compare it to the Superoutbreak than the number rated EF5. Amazingly, the April 2011 death toll already appears to be worse!


View the original article here

Friday, January 18, 2013

A tornado-producing machine

Tonight at 8pm EDT, TWC will be airing a special program on the recent historic tornado outbreak, called "Twisters: Trail of Destruction." Here are some additional reflections on the three-day onslaught, and we'd be interested in yours via comments to this entry. Our thoughts are with those who have experienced the wrath of the atmosphere.


The outbreak on Thursday, Friday and Saturday, April 14-16, 2011 from Tushka, Oklahoma to Askewville, North Carolina left many memorable images. Here are a couple: this photo of schoolchildren looking out the window at a tornado in Clinton, Mississippi (why were they not taking shelter?), and a man sitting in his car and calmly observing as a vicious tornado races in his direction (those are not leaves as he says, they're pieces of buildings!).



Source: http://yfrog.com/hsvctwhj


This outbreak didn't match the most intense one on record, the Superoutbreak of April 3-4, 1974. That produced numbers which no outbreak in recorded history before or since has come close to rivaling: of the 148 tornadoes within 24 hours, 30 were of at least F4 on the Fujita Scale (now known as the Enhanced Fujita Scale, with EF instead of F ratings), including six F5s.

What made the recent one so notable was the way it was so potent and tragic three days in a row, culminating in one of the deadliest tornado outbreaks in the history of North Carolina along with destruction that was extraordinarily widespread for that part of the country.

And what occurred meteorologically to result in that was the nature of a sharp dip in a strong jet stream, which took the shape of what meteorologists call a "negatively tilted trough," and how that plowed east like a machine, producing spinning, deadly tornadic supercells day after day.

This set of maps illustrates what I'm talking about. The way the dashed line representing the trough axis extends from northwest to southeast is the "negative tilt," as opposed to a positive tilt, which would be from northeast to southwest, or a neutral one, which is due north-south. All kinds of troughs can be associated with thunderstorm outbreaks, snowstorms, and other hazardous weather, but on average the negative tilts tend to have a little extra oomph, and this was an exceptionally strong and persistent one.


Those upper-level jet stream maps, by the way, have some similarities to the pattern present for big outbreaks last May in Oklahoma, April 1998 in the Deep South, and March 1984 in the Carolinas ... except this time it happened on three consecutive days.

With this kind of dip, the jet stream energy tends to really punch over the warm, humid, unstable air ahead of it, conducive to severe storms. Also, the air ahead of the trough spreads widely apart in upper levels of the atmosphere (a particularly vivid example of which is above, as I illustrated on the Friday map with the arrows that follow along with the wind flags), which helps lead to thunderstorm development as air rises to take the place of the air evacuated above.

[There's a whole separate technical topic of "diffluence" vs. "divergence," but that's beyond the scope of this blog! Readers who are interested in learning more about that can find a quick tutorial here.]

Then, with the right combination of other ingredients such as winds at different levels of the atmosphere blowing in different directions, tornadoes can form. Those ingredients were also strongly present on Thursday, Friday, and Saturday.

It's not uncommon to get this kind of trough. What's unusual is the way it kept its form, and kept slamming nearly due east day after day. As a friend of a friend on Facebook (you can sign up for my weather posts on my TWC Facebook fan page) noted, these troughs often either lift quickly to the northeast and become somewhat disconnected to the most explosive instability, or they become "cutoff lows," in which, as the name sounds, they cut off from the main jet stream and grind to a halt, and can still produce very inclement weather but generally not bad tornado outbreaks.

There's no rest for the weary, with, per the graphics below, another such trough coming, which is going to bring about another collision with warm, moist, unstable air tomorrow (Tuesday) and Tuesday night. The main threat area will be in the Mid-Mississippi Valley into the Ohio Valley.


Source of images: wright-weather.com


This time, though, the system will swing northeast rather than crashing over the Carolinas and Virginia. It'll be a two-day outbreak, not three, and tornado-producing ingredients on Wednesday are not expected to be present to the degree they were on Saturday when that system came east. There will be a lot of wind energy, though, so a threat for damaging storms will exist in places such as PA, NY, and New England, and at least some risk of energetic thunderstorms into the Deep South.

It's been a wild month, starting with what was, by the standards of straight-line wind damage events rather than tornadoes, a superoutbreak on April 4; then a destructive evening in Iowa on April 9 and the following day an outbreak in Wisconsin which was record-setting for that state; then the most recent siege last Thursday, Friday, and Saturday, and now the upcoming system ... And looking ahead, the pattern will stay active this weekend and into next week with the potential for additional severe thunderstorms as well as flooding rains in the nation's midsection.

Stay safe, everyone!


View the original article here

Thursday, January 17, 2013

The Katrina of tornado outbreaks

Our thoughts at TWC are with those who have been affected by the recent siege of severe weather including twisters, wind/hail damage, and flooding.

Here are some thoughts about last week's catastrophic tornado outbreak ...


Terrible perfection

I posted that graphic last Wednesday afternoon on my TWC Facebook page. The ingredients were "textbook." I mean, literally what I learned from a textbook more than 30 years ago. The atmosphere was explosively unstable with summerlike heat and humidity, interacting with a classic wind shear setup as a strong jet stream and upper-level trough crashed overhead. Also, dry air aloft (dark red shades on the left image below) put a lid on things and allowed the energy to build up until it blew sky high.



[Image source: NCAR/UCAR]


Not only were the elements perfect for a tornado outbreak, they were present to an extreme degree. The observed EHI ("Energy Helicity Index"), a measure which represents a combination of instability and wind shear, was extraordinary, higher than during the time of two notorious [E]F5s, the Moore, Oklahoma and Greensburg, Kansas tornadoes on May 3, 1999 and May 4, 2007, respectively.

Such a set of combustible ingredients, plus a remarkable number of supercells with hook echoes on radar and "ground-truth" observations of tornadoes, led Dr. Forbes and me to decide to up TWC's "TOR:CON" index to a 10 for northern Alabama, meaning a 100% chance of a tornado within 50 miles, the first time that's been done since the product was developed a couple of years ago.


Capricious

Many counties have been affected by the calamity, with the effects extending beyond just those people and locations struck directly by the tornadoes. Yet even with this widespread an outbreak, an extremely small percentage of the land area of northern and central AL was actually hit.

Above are screen captures from a video taken from a helicopter during Dr. Forbes' aerial survey of the damage. Tornadoes never cease to amaze me in their capriciousness, even in a situation such as this with relatively widespread devastation, leaving one part of a neighborhood unscathed while an adjacent one is in ruins.


Tornado Alley?

Last week's outbreak, and the past month of tornadoes, reinforce that "Tornado Alley" is *not* just in the Great Plains.

The first map below is one that in the past TWC has shown, and NOAA has graphics online depicting a similar area.

The second map plots all tornadoes in the official database which are [E]F 3 and higher on the [Enhanced] Fujita scale, those which account for approximately 3/4 of all tornado fatalities. IMO, true Tornado Alley is represented by the much broader area in which all those red lines are concentrated.


What about climate change / global warming?

What's needed relative to this question is an apolitical, non-reactionary, objective assessment. However, as soon as the extremity of last week's outbreak became apparent, there were, as is usually the case, reactions on two extremes. One headline on the web blared that hundreds were killed in "states represented by climate pollution deniers," while a high-ranking federal government official was reported to have dismissed climate change as a factor, quoted as saying, "Actually what we're seeing is springtime."

The former is obscene and the latter fails to represent what's happened weatherwise recently, which actually, no, has not been a typical month in spring.

On the one hand there is no decisive trend in overall tornado occurrences, and while in recent years there's been a rash of outbreaks which have been unusually far north and intense for the time of year (including the one in Wisconsin last month), the one last Wednesday was geographically consistent with April climatology.

On the other hand, this event needs to be considered in the *context* of the relentless series of severe thunderstorm and tornado outbreaks which started on April 4 and culminated on the 27th. The number of severe weather reports and confirmed tornadoes has been atypical even by April standards, shattering the previous records. Even taking into account limitations of the historical record, the numbers have been stunning.

As noted above, the combination of instability and wind shear was extreme even by classic tornado setup standards. The temperature in Laredo reached 111 degrees the day prior to the peak outbreak, the hottest on record at that location for so early in the season. Precipitation extremes have been extreme even by extreme precipitation standards, with April rainfall upwards of 20" in Arkansas and record levels on some rivers in the central U.S., juxtaposed with an exceptionally large amount of Texas being classified in extreme or exceptional drought. [Tue May 3 addendum: And the warmest April on record in the UK.]

And all of this is in the context of a relentless series of extreme weather events in the U.S. and other countries during the months preceding April, and many others worldwide during recent years which I've documented and which have had apparent a physical connection with a warmer atmosphere.

I've also read categorical statements assigning a one-to-one cause-effect attribution to La Nina. But while La Nina is present now as it was during the 1974 Superoutbreak, it was not during some of the other most notorious outbreaks of all time, such as the 2002 Van Wert / Mossy Grove, 1999 Oklahoma, 1991 Andover KS, 1984 Carolinas, and 1965 Palm Sunday outbreaks.

The atmosphere is extraordinarily complex, and ultimately what's happened the past month is probably a combination of influences, including La Nina, other natural variability, and anthropogenic global warming.


Bigger than the Superoutbreak?

Hanging on the wall of my office at TWC (low-res cellphone pic above) is an original map of the April 3-4, 1974 Superoutbreak, which I've had since the '70s (a high-res online map can be seen via this link). As Dr. Forbes said a few days ago in his blog about it, that event is the benchmark for tornado outbreaks.

As soon as the number of tornado reports from last Wednesday exceeded 148, the number of tornadoes within 24 hours in the 1974 Superoutbreak, there was talk about this outbreak being bigger than that one. I sent an email to the staff at TWC on this topic and provided commentary about it on camera, as I wanted to make sure that there was awareness of how extreme The Superoutbreak was and that the proper perspective is being applied in comparing the two.

That one had *thirty* F4 or higher tornadoes on the original Fujita scale. Communities were reeling from that level of damage in Alabama, Georgia, Tennessee, North Carolina, Kentucky, Indiana, and Ohio. Among those 30, six F5s occurred across five of those states. Tornadoes struck along a total path length of more than *2500* miles.

We'll need to await the final numbers before doing a final comparison, but with the latest information as of this writing, and even accounting for subjectivity and changes in tornado assessments over the years and decades as the Fujita Scale evolved into the Enhanced Fujita Scale, it looks like the April 27, 2011 outbreak will fall far short of some of those '74 numbers.

It's not just all about the total number of tornadoes, plus, despite definitive official statements about a total of 211 having occurred (and a report today that it's been raised to 312!), any such estimates are premature, as those are just preliminary *reports*, some of which were duplicates of the same long-track tornadoes.

That all having been said, no matter how this all shakes out in the end, the April 27, 2011 outbreak will go down as one of the biggest and worst on record. The amount of energy it unleashed is hard to comprehend.

By why do any of these such statistics even matter? Well, scientific assessments of ingredients and results help meteorologists understand the phenomena and factors and climatology involved, and apply that to forecasting future events.

But to people who have lost their lives, and their surviving family, friends, and colleagues, the meteorological statistics don't matter. Those folks are gone. And the latest death toll is now well over 300 and higher than that of the Superoutbreak and among the few highest on record in the U.S. from a tornado outbreak, and with many other people still unaccounted for.


The Katrina of tornado outbreaks

So that makes this the Katrina of tornado outbreaks, in the sense that it's a vivid and tragic reminder that although high death tolls from tornadoes and hurricanes are much less common than they were in the 19th and first part of the 20th centuries, we are not immune to them, even in this era of modern meteorological and communication technology.

Timely and accurate outlooks were disseminated in the hours and days leading up to the outbreak as well as short-term warnings once the supercells formed. This included "tornado emergency" level warnings by the National Weather Service; in fact, there were so many of those issued that it was mind-boggling.

I think I speak for all meteorologists/forecasters when I say that I/we are at peace with feeling like we did everything we could while also being heartbroken that it still wasn't enough. My heart sank as more and more reports of extreme damage came in that evening with a fatality count that has kept rising since then.

The power of the atmosphere is overwhelming, and how vulnerable we are to it has been reinforced yet again. Weather is as awe-inspiring, fascinating, mysterious, fearsome, and humbling as when I first became obsessed with it as a child. I wish it didn't have to have such tragic consequences.


[Image source: http://bit.ly/jlOpvd]


ADDENDUM 3PM EDT TUESDAY MAY 3, 2011

To follow up on some of the comments received so far ...

For those who do not understand why I chose Katrina as the hurricane to highlight, perhaps this will help. It illustrates what I was referring to in that portion of the blog entry, which is the death toll of tornado outbreaks and hurricanes in the era of modern technology vs. prior to that.




View the original article here

Climate Dice- The Sixth Roll: Lottery Numbers For Summer 2012

The Power Ball (or overall National Climatic Data Center Ranking) number for summer 2012 came up as 116, the third warmest ranking on record for the lower 48 states for any summer. A ranking of 1 would have been the coldest possible ranking. The National Climatic Data Center has been ranking months, seasons and years from 1 to 118 since 1895 with 1 being the coldest possible temperature average ranking and 118 being the warmest possible temperature average. In the Climate Lottery game, I've defined each individual lottery number as rankings for each month for the lower 48 states, Power Ball numbers as those for each season, and Mega Ball numbers as those for each year. As we keep seeing over and over again the Climate Lottery game is rigged towards those higher number rankings. For everyone who participated in my fourth lottery contest, the numbers were: 105/118/103 for JUN/JUL/AUG 2012 with an overall Power Ball ranking for the season of 116. Just like summer and fall 2011, winter 2012, and spring 2012 not even one month was below average. Above average rankings have occurred for every month since (and including) June 2011. In fact, the lower 48 states have never had 15 straight months of above average temperatures since records have been kept in 1895... a phenomenon that I HIGHLY think is due to man induced global warming.

The winner was Buzz Bernard (again!) who came closest to picking the correct numbers. His picks were 118/115/100 with a "power ball" ranking of 114 for JUN/JUL/AUG 2012. Good going Buzz, we'll all have to look a little closer at the data to beat you next time. Buzz had previously won the contest for winter 2011/2012.

Well, let's play the lottery again. I wonder if we will ever see in the future a "gotcha" set of three months when temperatures are below average for an entire season across the lower 48 states. Just like last time pick three numbers between 1 and 118 (with one representing the coldest possible ranking and 118 being the highest possible ranking) for SEP/AUG/SEP 2012. Also pick a "Power Ball" or overall ranking number for fall 2012 between 1 and 118. Please give your picks in the reply section to this blog by October 1st. As usual, if you wait until just before October 1st to make your picks, you can get an educated guess as to what the ranking for September will be. I'll announce another winner shortly after the National Climatic Data Center processes fall averages and rankings on my next post around December the 10th, 2012. I won't be shocked, at all though again, if just like last summer, fall, winter, and this spring and summer not one single month of fall is below average.

For reference the following are links to my first five posts:

http://www.weather.com/blog/weather/8_26573.html?from=blog_permalink_mainindex">http://www.weather.com/outlook/weather-news/news/articles/climate-dice-fifth-roll-blog_2012-06-25

http://www.weather.com/blog/weather/8_26573.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_26573.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_26102.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_25602.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_23192.html?from=blog_permalink_month


Once again, the summer season, as a whole, was above long term averages with no individual month below average; and thus, having above average rankings. I'll reiterate once more (I know that this is getting repetitive) that due to climate change it is unlikely for a land area the size of the contiguous United States to have below average temperatures for an entire season. I'm not going to state that there will NEVER AGAIN be another below average season for the United States, but due to man induced global warming, the chances for an entire season of below average conditions is becoming much less likely. The whole point of these posts is to demonstrate how skewed temperatures have become towards warmth due to climate change...and they were very skewed towards warmth this summer. As stated in my fourth post, only an increase in volcanic activity from what is presently occurring at the moment can significantly slow the overall warming trend of the planet. What has happened so far this year is yet more proof of the climate dice being loaded for warmth in the United States.

The summer heat got deadly this season. Over one hundred people were killed due to heat related issues in the United States. If this summer is any indication of what is to happen in the future, we will all be dreading the advent of the summer solstice and yearning for fall to come quickly. Going back to my first blog, I've been looking closely at temperature averages since my career began at TWC in the 1980s and record temperature data since the late 1990s. In fact, a log of record data that I started on 1/1/2000 led to a peer review science paper indicating that the ratio of record highs to record lows will increase with time during the 21st century should the pace of global warming continue as predicted by climate science's current models. For an overview and summary please see: http://www.agu.org/pubs/crossref/2009/2009GL040736.shtml
The public doesn't mind if there is a record high of say 70 in New York City during the middle of January...in fact it may be welcome, but people do feel uncomfortable, and actually can die if a record high of over 100 occurs in that same city during the summer. Such was the case during the summer of 2012 when 9685 daily records were set, 358 of which were all-time records. For a horrifying preview of a world to come see the Rolling Stones post at: http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719


Here's a breakdown of the National Climatic Center's ranking numbers for each month of the summer:

In June the overall ranking for the lower 48 states was 105 (out of 118):


The historic early heat wave of late spring/early summer started in the Inter-Mountain West. Colorado had its warmest June in recorded history. You can pick out the individual rankings for each state from each map that I will present. The devastating fires in Colorado were a direct result of the early season heat accompanied by drought. The Southeast started out the month on a cool note, but Atlanta, where I live, had an all-time record high of 106 on the last day of June. The heat from the Plains spread east by the end of the month. 343 all-time records were set from late June into July across the U.S.

In July the overall ranking for the lower 48 states was 118 (out of 118).


Oh my! July was the hottest July in recorded history for the lower 48 states. Not only that, it was THE WARMEST MONTH in recorded history. The previous warmest month was July 1936 during the height of the Dust Bowl.
It was only a few months ago that March 2012 also ranked at 118...remarkable! Again, the ranking for each month is not an average of the rankings for each individual state, but a comparison of the averages of all prior years since 1895 for the entire lower 48 states.

In August the overall ranking for the lower 48 states was 103 (out of 118).


In August the jet stream dipped southward into the eastern U.S. allowing cooler than average air masses to penetrate deep into the South; but high pressure aloft continued to cook the West and much of the Plains. It was still warm enough from coast to coast for August to be the 16th warmest August (out of 118) on record.

The overall ranking for summer 2012 was 116 (out of 118)...The third hottest summer on record.


Again, I am getting all of my ranking numbers from the National Climatic Data Center.
The link for the National Climatic Data Center's Climate at a Glance Site where the rankings are archived is: http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html

I'm keeping the format on all of my charts the same as on the last three posts. The average ranking for 2012 is
59 since the coldest ranking would be 1 and the hottest would be 118. I have color coded all rankings for this post at or below 38 blue and all those at or above 79 red with rankings + or -- 19 from the median value of 59 black.

The following are the rankings so far for the 2010's:


Also, for reference, the following are "Power-Ball" and "Mega-Ball" ranking numbers for 2000 to the present.
Please see my prior posts for more charts dating back to 1900. Seasonal or Power-Ball rankings for winter are those for DEC/JAN/FEB, spring are those for MAR/APR/MAY, summer is JUN/JUL/AUG, and fall is SEP/OCT/NOV. Also, keep in mind that NCDC rankings for seasons compare seasons and are not merely an average of rankings of individual months of a season or year.



Notice that since the start of 2000 only five out of fifty-one seasons have been below average or "blue". Thirty-six out of the fifty-one seasons since 2000 have been "red" or above average. Indeed, as stated in the last post, the climate dice are very much loaded for above average temperatures for the lower 48 states looking at recent history.
I hope that everyone will have a pleasant fall. Even if fall ends up being well above average, at least it will be cooler than what has occurred during this torrid summer.

Click here to leave a comment and play the climate lottery.

Guy Walton
Lead Forecaster, the Weather Channel


View the original article here

Wednesday, January 16, 2013

Climate Dice- The Second Roll

Last September I wrote my first blog entitled "The Climate Dice Are Loaded", which was a piece intended to link the heat of the summer of 2010 with global warming. Over the last three decades there has certainly been a warming trend across the country, but on a seasonal time-frame below normal averages are still occurring. Such has been the case so far in 2011. At the end of the first blog I quipped "Stay tuned to TWC and keep note of averages at your location...and if you like cold temperatures let's see if you get lucky." Well, guess what? Those who like cold, snowy weather east of the Rockies did get lucky. The last two winters have seen a lot of cold, snowy weather in the East. Denialists can always point to each cold wave or snow storm as proof that anthropogenic global warming is not occurring. It's just variable "weather." But can denialists cling to the "It's Just Weather" argument for another decade or two? Ultimately, I know that the future of the planet's temperature trends the next couple of decades will be the key to winning or losing the global warming argument with the general population. Let's look at yet another set of statistics indicating that there is a warming trend.

Instead of looking at complicated graphs and charts of temperature averages and records, a simpler statistical way of looking at overall trends in the lower 48 states comes from The National Climatic Center's Climate at a Glance Site: http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html

Click on the following items once you get in the site in order to get individual monthly and yearly averages:

The site ranks months, seasons and years for the lower 48 states from values of 1 (coldest in recorded history) to 117 (warmest in recorded history). Rankings start with the year 1895. Each ranking is calculated using averages of surface temperature data recorded from approximately 5000 stations across the lower 48 states processed by the National Climatic Data Center. I've plotted the rankings on charts for the last 30 plus years for the purpose of this discussion. To make the charts easier to follow trends, I've color coded the warm months and years in red (those that have rankings above 69) and color coded the cold months and years in blue (those that have rankings below 48). The near average months are shaded in black (+ 10 or -- 10 from the average value of 58.5).

Notice after looking at the Climate at a Glance Site that as the years go by there is a lot more red rankings, particularly from the late 1990's to the present time.

Starting in December 1997 one can see that a vast majority of the months and years in the lower 48 states are red rankings. The last yearly blue ranking was in 1993, and the last black, or near neutral year, was in 1996. That trend has continued into this decade. Notice also that there have only been two instances when there were three consecutive monthly blue rankings since December 1997...from June 2004 through August 2004, which was a cool summer; and the most recent winter of 2010 to 2011.

Also notice that the trend of blue rankings being scattered haphazardly through the months of each year has not changed since the 1980's. There is no evidence, at all, that individual months such as January or August have a better chance of being blue. There is great debate, however, within the climatology community that future winters across North America maybe colder that average due to stronger negative North Atlantic Oscillations with the culprit being global warming given what has happened in the last couple of years. If that's the case, then the climate dice from December through February will be loaded for more blue rankings in the next several years. The climate dice are loaded towards red, overall, but the planet has not warmed enough for ALL of the individual months or seasons to rank above long term averages...at least not yet!

Last month the ranking was 116, meaning that August 2011 was the 2nd hottest August on record since 1895...enough to raise more than a few eyebrows among meteorologists and climatologists. The rankings on the charts are a compilation of the lower 48 individual state rankings and can be found at the following National Climatic Center address: http://www.ncdc.noaa.gov/sotc/national/

For example, the following charts show that the overall ranking of 116 for August 2011 is basically an average of all 48 states. Not all of the states were hot, but there were no states experiencing below average rankings.

So, if one was to do seasonal forecasts for the lower 48 states they MUST keep in mind how the climate has been behaving over the last thirty plus years; otherwise, there will be too much of a cold bias. A seasonal forecast that has a decent chance of verifying well will take into account the fact that temperatures have been above average since the 1970s's as well as a myriad of other factors such as ocean temperatures or the North Atlantic Oscillation.

It will be interesting to see how boreal autumn verifies this year across the continental U.S. If one was to forecast the coldest three months of fall in recorded history for the contiguous U.S. (the lower 48 states) the ranking numbers would be 1/1/1. The warmest three months of fall in recorded history would be 117/117/117. Boreal summer (JUN/JUL/AUG) verified as 92/114/116. The overall ranking for summer 2011 was 116 coming in second to the summer of 1936. The overall ranking for summer is not an average of June, July and August; rather a ranking compared to all other summers. You can follow the progress of each month since the National Climatic Data Center processes and reports the data for the prior month around the 10th at: http://lwf.ncdc.noaa.gov/sotc/national/

By no means am I an expert at seasonal forecasting, but the following are my "quick picks": I'm forecasting rankings of SEP/OCT/NOV of 75/68/32. It appears that September will be above average in the West with below average conditions in the East, while overall being above average. Conditions may cool into October due to some strengthening of a cold vortex which typically resides over Hudson Bay. We could see a cold November since by that point, looking at the charts, the lower 48 states will be "due" for a blue ranking. Monthly "streaks" of red rankings have lasted, on average, five to six months since December 1997. The overall ranking of boreal fall may well be above the average of 58.5. It is becoming increasingly difficult for the climate dice to land in the blue, or below average, level for an entire season across the continental U.S. due to global warming.

Well, I bet you can out-forecast me. If you wish, in the reply section to this blog (you will need to click the comments section highlighted in blue), enter your first name or a made up name, then forecast some "climate lottery picks" for autumn. I'll give everyone until midnight October 15th to make some picks. By that point in time, after following my instructions, you should be able to correctly pick the ranking for September. Also, you'll get up to a 15 day lead on me for the October forecast. I'll try to determine who the winner is by looking at all the posts shortly after December 10th. Shortly after December 15th, I'll give a short meteorological summary for each month explaining why each month of boreal fall verified red, blue or black on the post Climate Dice Three.

Well, continue studying how those climate dice are loaded and good luck making any picks!

Guy


View the original article here

Tuesday, January 15, 2013

April 2011 - The Tornado Numbers Are In!

The National Weather Service and Storm Prediction Center have now compiled and released the official counts of the actual number of tornadoes that occurred in April 2011. Until now there had only been preliminary counts, which often include duplicate reports of multiple sightings of the same tornado.

The actual number of tornadoes in April 2011 is a staggering 753! This is 2.8 times the old April record of 267 set in 1974 (which included the April 3-4 "Superoutbreak"). It's over 200 more than the previous record for ANY month, which was 542 in May 2003.

The table below shows additional statistics from the incredible April. There were 364 fatalities. That's the most for any month since April 1936 when there were 509 tornado deaths. There were four tornadoes rated EF5 (all on April 27). That's the most for any month (and any day) since 1974 when there were seven rated F5 on April 3 (by NWS; Fujita rated six of them F5).

April 27th brought the most tornadoes. The National Weather Service keeps records for calendar days using Central Standard Time (CST), and there were 202 on April 27, the most on record for any such day. There were 320 fatalities on that day, third deadliest in United States history and deadliest since March 21, 1932.

These new statistics update those from previous blogs, including one from June 13 and one on April 29. Stu Ostro also wrote blogs on May 2 and on April 18 about some of these tornadoes.

May 2011 was also an active tornado month, including the tragic Joplin, Missouri tornado on May 22. Then National Weather Service now lists 157 direct deaths from that tornado, plus additional indirect fatalities.

In all, 55 killer tornadoes have brought 546 direct deaths so far in 2011. My preliminary tornado count (including the actual tornado counts through April and my best estimates subsequently) is 1476 tornadoes through July 31. That's the most on record for the first seven months of the year, beating out 2008 which had 1397 in that period.

So we're still on a record tornado pace for the year, but the pace has fortunately slowed over the past two months. In an average year 348 tornadoes (27% of the yearly total) occur during the months from August through December. A substantial number of them typically come from tropical cyclones. Others come from frontal systems in the fall and early winter. No month is safe from tornadoes. Hopefully none will be as bad as what we've already seen this year!


View the original article here

Monday, January 14, 2013

The costliest just got even costlier

The document titled "The Deadliest, Costliest, and Most Intense United States Tropical Cyclones" is *the* official go-to source for those statistics and related information.

It was first published in 1978 (at least that's the first listing of it here). At that time, the costliest U.S. tropical cyclone was "only" $2.1 billion (which when adjusted for inflation to 2010 would be $11.76 billion).


The report has periodically been updated, and the latest, by Eric Blake and Chris Landsea of the National Hurricane Center (NHC) and Ethan Gibney of the National Climatic Data Center (NCDC), has just been posted.

My weather.com colleague Jon Erdman and I have compiled some highlights of new information and changes that are in this update.

Most notably, the estimate of direct damage produced by Hurricane Katrina is now $108 billion. As if the previous estimate of $81B wasn't stunning enough! That makes Katrina the first hundred billion dollar hurricane. And that's just for direct damage, i.e. it does not include the untold indirect economic losses (or, of course, the emotional suffering of survivors and the staggering number of people who lost their lives, notwithstanding the fatality estimate having been revised downward in this update).

Here are a few key excerpts from the report's analysis (my bold):

>>>
The study by Jarrell et al. (1992) used 1990 census data to show that 85% of U.S. coastal residents from Texas to Maine had never experienced a direct hit by a major hurricane. This risk is higher today as an estimated 50 million residents have moved to coastal sections during the past twenty-five years.

The experience gained through the landfall of 7 major hurricanes during the past 7 years has not lessened an ever-growing concern brought by the continued increase in coastal populations.

Continued coastal growth and inflation will almost certainly result in every future major [Category 3+] landfalling hurricane (and even [some] weaker hurricanes and tropical storms) replacing one of the current costliest hurricanes. For example, all three of the U.S. hurricane landfalls of 2008 made the top 30 list, despite none of them being major hurricanes at landfall. [Stu's note: That includes not only Ike and Gustav, but even also Dolly.]

If warnings are heeded and preparedness plans developed, the death toll can be minimized. However, large property losses are inevitable in the absence of a significant change of attitude, policy, or laws governing building practices (codes and location) near the ocean.
>>>

And:
>>>
Katrina provided a grim reminder of what can happen in a hurricane landfall.

Sociologists estimate, however, that people only remember the worst effects of a hurricane for about seven years (B. Morrow, personal communication). One of the greatest concerns of the National Weather Service's (NWS) hurricane preparedness officials is that people will think that no more large loss of life will occur in a hurricane because of our advanced technology and improved hurricane forecasts.

Bill Read, current Director of NHC, as well as former NHC Directors, have repeatedly emphasized the great danger of a catastrophic loss of life in a future hurricane if proper preparedness plans for vulnerable areas are not formulated, maintained and executed.
>>>

And now we head into the heart of the 2011 Atlantic/Caribbean/Gulf season. Although the official hurricane season as a whole extends from just after Memorial Day till after Thanksgiving, on average there's a very pronounced peak from mid-August through September and into October. It never ceases to fascinate me how, right on cue, in most years things really ramp up between now (August 10) and Labor Day. (Five named storms have already formed this season, but they've been fairly small and weak, none became a hurricane, and at least one probably wouldn't have even been designated as a tropical storm in the pre-satellite era.)


All years are not equally productive. What about the peak of this season? Well, in late July I posted this (below) on my Facebook TWC fan page. Hopefully I'll have to post something a couple months from now saying how wrong that assessment was!

But as I also alluded to, a critical factor in the outcome of a season no matter how many storms develop or how strong they become is exactly where they go. The pattern is sending mixed messages as to what the predominant steering flow will be as we head through the peak of this season. At times it's evoking 2004 (Caribbean/Florida/Gulf). Alternatively it has hinted at a repeat of 2010 (missing U.S. to east and south). There has been talk about resemblance to the mid-1950s (East Coast).

Regardless, remember that all it takes is one to bring disaster, like Andrew in 1992 and Allison in 2001 did, in otherwise relatively uneventful seasons. Both are in that Top 10 costliest list.

Let's hope for the best this year, yet be prepared just in case.



View the original article here

The ridge, heat, humidity, drought, and Dust Bowl

Here come da ridge!


[ECMWF model forecast; image source: wright-weather.com]

For extremity of summertime ridges of high pressure aloft over the United States, meteorologists look at "500 millibar heights" -- in non-technical terms, that represents how high the pressure is a few miles above the Earth's surface -- and in particular how close those heights get to 600 decameters (19,685 feet). That's the benchmark, as it's about as high as those "heights" ever get.

And they're gonna get pretty close to that in a few days. [July 17 update: The 500 mb height reached 600 dm this evening over Omaha. Preliminary data suggests that's a record for that location and the farthest north 600 dm has been reached in the central states.]

Translation of all of that into what it means for people: The extreme heat of 2011, which has already been remarkable in parts of the country during the early part of the season including before summer officially even started, is about to expand as we enter into the next phase of the pattern.

[July 18 addendum: Wichita's # of 100+ degree days up through this point in the season and the average temp since June 1 have exceeded that of any year of the 1930s, and each is just shy of the highest, which occurred during the extreme heat wave of 1980.]

In the southern states, particularly the southern Plains, afternoon high temperatures have consistently been particularly extreme, assisted by how dry the soil is. Rather than some of the sun's energy going into evaporating soil moisture, it gets efficiently converted into quickly-rising temperatures each day.

And in turn, the soil dries out even more, worsening the drought.

Immediately adjacent, it's been the opposite, with exceptionally wet conditions including record flooding.

As the uber ridge expands and the heat surges north during the coming days, the atmosphere will have to work harder there than farther south for each degree of the afternoon high temperature, but any limitation in that department will be made up for in the heat index, a measure which is an attempt at quantifying the combination of heat and humidity.

Soil and crop moisture evaporating will boost the dewpoint, which translates to how humid the air feels. Dewpoints and heat indices are expected to rise to exceptionally high levels as far north as parts of the Dakotas and Minnesota this weekend into early next week.


What's more, overnight low temperatures will be quite high along with oppressive humidity.

Please be careful and take precautions! Heat (including the effects of humidity) nowadays is typically the #1 weather-related killer in the U.S. (other than vehicular accidents due to wet, snowy, or icy roads), with an estimated 1,500 each year dying on average.

This season is shaping up to be a memorable hot summer along with those such as the ones in 1930, 1934, 1936, 1954, 1980, and 1988.

We'll have to see when all is said and done, looking back from the vantage point of when we get to September and October, exactly how 2011 ends up stacking up.

There are various ways of comparing the heat, including the persistence, expanse and extremity of it.

In regard to the latter, many state high temperature records were set in the 1930s during the peak of the Dust Bowl, especially in 1936.

A significant contributor to that was the expanse of the drought.

You might be familiar with Drought Monitor maps that appear on The Weather Channel and weather.com. The Drought Monitor is a great initiative and set of products, however a significant limitation for historical perspective is that the maps and data that we have become so accustomed to and reliant upon exist only back to 2000.

The Palmer Drought Severity Index (PDSI), one of the inputs to the Drought Monitor product, is available back more than a century.

It focuses on long-term water levels rather than short-term moisture (though is at least partly also reflective of the latter).

The map plots below represent, as best as I can tell, a reasonable apples-to-apples comparison between the current drought and that during the peak of the Dust Bowl, in particular 1936, when 14 states set record high temperatures that still stand. (There were other factors that made the Dust Bowl what it was; here I'm referring specifically to meteorological and hydrological ones.)

These are maps for June since that's the latest month for which one is available for in 2011, and there haven't been any huge changes during the first couple weeks of July.

You can see the extraordinary dichotomy of extreme wet/dry that exists in such close juxtaposition to each other this spring & summer in the U.S., as well as the much greater expanse of drought in the mid-1930s. That helped boost temps in many states to values that have not been exceeded since.




Although the current drought is not as expansive, by this measure the driest categories are actually more prevalent than in June 1936. [July 17 addendum: A 9-month lack of precipitation in Midland shattered the previous record.]

The combination of expanse and severity stands out more in 1934. In both of those 1930s Junes, the focus was farther north than in 2011.


[PDSI images source: NOAA/ESRL Physical Sciences Division.]


What happened in the 1930s and other decades reinforces that there have always been extremes in weather, and there is always natural variability at play. What's changing now is the nature of those extremes, and also what's important is the context.

This time, the extreme drought, heat, and wildfires are occurring along with U.S. extremes this year in rainfall, snowfall, flooding, and tornadoes, and many other stunning temperature and precipitation extremes elsewhere in the world in recent years as well as, as I posted on my TWC Facebook "fan" page, record-shattering 500 millibar heights in high latitudes. And all of this is happening while there's an alarming drop in the amount of Arctic sea ice.

The nature and context of the extremes is the difference between the 1930s and now.


[Source: Polar Science Center; click on image for full-sized version.]


View the original article here

Sunday, January 13, 2013

Weather phobias

[This is a repost of an entry which had outdated links. That original entry and reader comments are here.]


As is mentioned in my bio, my desire to become a meteorologist was rooted in a phobia of thunder and lightning. A lot of kids are scared of thunderstorms, but mine went way beyond a normal childhood fear. I was petrified at the sound of thunder or the flash of lightning, especially at night.

I'm not sure exactly how old I was, but probably sometime during elementary school age I snuck into my parents' room and hid under their bed all night because I was worried there MIGHT be a thunderstorm.

My father, upon awakening in the morning, couldn't find me. Finally he did. The subsequent exchange went something like this:

"What in the world are you doing under there?!"

"I was worried there'd be a thunderstorm."

"But Stu, there's not a cloud in the sky!"

That fright is what triggered my curiosity, fascination, and even obsession with the weather. It has lasted my whole life. Fortunately, my phobia has not, although in certain situations lightning still makes me more uneasy than most people. For awhile I actually went too far in the other direction and became a little too nonchalant ... until a couple of close calls jolted me (figuratively, fortunately not literally).

With that background, I was quite interested to hear about a new study on weather phobias (focusing specifically on severe thunderstorms and tornadoes).

There even used to be a website (now defunct) which was exclusively devoted to storm phobias, and I'm certainly not the only one who has experienced some of these phobic symptoms!


View the original article here

Friday, January 11, 2013

Climate Dice- The Sixth Roll: Lottery Numbers For Fall 2012

Blog: Climate Dice- The Seventh Roll: Lottery Numbers For Fall 2012

The winning climate lottery numbers for fall (SEP/OCT/NOV) 2012 were 101/44/99, and the Power Ball number was 98

The Power Ball (or overall National Climatic Data Center Ranking) number for fall 2012 came up as 98, which was the 21st warmest for any fall on record for the lower 48 states. A ranking of 1 would have been the coldest possible ranking. The National Climatic Data Center has been ranking months, seasons and years from 1 to 118 since 1895 with 1 being the coldest possible temperature average ranking and 118 being the warmest possible temperature average. In the Climate Lottery game, I've defined each individual lottery number as rankings for each month for the lower 48 states, Power Ball numbers as those for each season, and Mega Ball numbers as those for each year. As we keep seeing over and over again the Climate Lottery game is rigged towards those higher number rankings. Above average rankings have occurred for every month since (and including) June 2011 up until October 2012 when near normal conditions occurred.

There was no clear winner for fall 2012. If I can get a consensus who the winner was, I will post an update.

Well, let's play the lottery again. I wonder if we will ever see in the future a "gotcha" set of three months when temperatures are below average for an entire season across the lower 48 states. Pick three numbers between 1 and 118 (with one representing the coldest possible ranking and 118 being the highest possible ranking) for DEC 2012. The highest possible ranking will be 119 for JAN and FEB 2013. Also pick a "Power Ball" or overall ranking number for winter 2012 between 1 and 118. Please give your picks in the reply section to this blog by January 5th, 2013...I'm giving folks a bit more time this go round due to the holidays. As usual, if you wait until just before January 5th to make your picks, you can get an educated guess as to what the ranking for December will be (and also a heads-up guess for January). I'll announce another winner shortly after the National Climatic Data Center processes fall averages and rankings on my next post around March 10th, 2012. Just for kicks and grins, pick the "Mega-ball" number for 2012...if you've been following along, this should be easy.

Here's a hint for December 2012: up to this writing 1,220 daily record highs have either been tied or set while only 6 daily record lows have either been tied or set.
See: http://www.ncdc.noaa.gov/extremes/records/daily/maxt/2012/12/00?sts[]=US#records_look_up for the latest update.

For reference the following are links to my first six posts:

http:// http://www.weather.com/blog/weather/8_28110.html?from=blog_permalink_mainindex

http://www.weather.com/outlook/weather-news/news/articles/climate-dice-fifth-roll-blog_2012-06-25

http://www.weather.com/blog/weather/8_26573.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_26102.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_25602.html?from=blog_permalink_mainindex

http://www.weather.com/blog/weather/8_23192.html?from=blog_permalink_month

Once again, the fall season, as a whole, was above long term averages, but we saw finally saw one month below average for the first time since June 2011...October 2012. I'll reiterate once more (I know that this is getting repetitive) that due to climate change it is unlikely for a land area the size of the contiguous United States to have below average temperatures for an entire season. I'm not going to state that there will NEVER AGAIN be another below average season for the United States, but due to man induced global warming, the chances for an entire season of below average conditions is becoming much less likely. The whole point of these posts is to demonstrate how skewed temperatures have become towards warmth due to climate change...and they were much skewed towards warmth again this fall. As stated in my fourth post, only an increase in volcanic activity from what is presently occurring at the moment can significantly slow the overall warming trend of the planet. What has happened so far this year is yet more proof of the climate dice being loaded for warmth in the United States.

Here's a breakdown of the National Climatic Center's ranking numbers for each month of the fall:

In September the overall ranking for the lower 48 states was 101 (out of 118):


The jet stream was oriented such that very warm weather persisted in the West with cooler than average temperatures occurring in the Midwest. Nevertheless the overall raking for the U.S. came up as 101...well above the average of 59 and very much in the red as far as rankings go. Looking at the map you can pick out each individual state ranking. Again the overall ranking of 101 is not an average of the 48 individual state rankings; rather the ranking is a comparison of temperature averages for the lower 48 states for September since 1895.

In the last couple of months NCDC revised September's ranking from 96 to 101, so Eric Fisher with his guess of 100 was the winner for that month...good going Eric!

In October the overall ranking for the lower 48 states was 44 (out of 118):


October 2012 was a good example of how the atmosphere can line up to produce cooler than average conditions for a large geographical area, such as the continental U.S., despite an overall warming trend across the planet due to man induced climate change. One huge event did occur at the end of the month, which many climatologists attribute to climate change: Hurricane Sandy. For more on Sandy see Andrew Friedman's post from Climate Central at: http://www.climatecentral.org/news/how-global-warming-made-hurricane-sandy-worse-15190


For the contest of fall 2012 Dr. Jeff Masters and I tied for the best picks for October, which was 85...good going, Jeff! Our picks were too warm, overall, for the month but they were the lowest of everyone who played.

In November the overall ranking for the lower 48 states was 99 (out of 118):


The jet stream was oriented such that there was a ridge keeping conditions very warm in the West while during the early part of November cold conditions were prevalent in the East.

Our old friend Buzz Bernard was dead on target with a prediction of 99 as his pick for November...way to go Buzz for the best pick for November!

The overall ranking for fall 2012 was 98 (out of 118)...The 21st warmest fall on record.


Nevada had its warmest fall on record. Despite cold conditions in the East, the overall ranking reflecting average temperatures was well above average for the lower 48 states.

Buzz Bernard did it again...his guess of 100 for the "Power-Ball" was closest to the ranking of 98.

I am getting all of my ranking numbers from the National Climatic Data Center.
The link for the National Climatic Data Center's Climate at a Glance Site where the rankings are archived is: http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html

I'm keeping the format on all of my charts the same as on the last three posts. The average ranking for 2012 is
59 since the coldest ranking would be 1 and the hottest would be 118. I have color coded all rankings for this post at or below 38 blue and all those at or above 79 red with rankings + or -- 19 from the median value of 59 black.

The following are the rankings so far for the 2010's:


Also, for reference, the following are "Power-Ball" and "Mega-Ball" ranking numbers for 2000 to the present.
Please see my prior posts for more charts dating back to 1900. Seasonal or Power-Ball rankings for winter are those for DEC/JAN/FEB, spring are those for MAR/APR/MAY, summer is JUN/JUL/AUG, and fall is SEP/OCT/NOV. Also, keep in mind that NCDC rankings for seasons compare seasons and are not merely an average of rankings of individual months of a season or year.



Notice that since the start of 2000 only five out of fifty-two seasons have been below average or "blue". Thirty-seven out of the fifty-two seasons since 2000 have been "red" or above average. Indeed, as stated in the last post, the climate dice are very much loaded for above average temperatures for the lower 48 states looking at recent history.
I hope that everyone will have a great winter. We'll see if this winter turns out to be colder and snowier than that of 2011/2012 despite December 2012 starting out so warm.

Click here to leave a comment and play the climate lottery.

Guy Walton
Lead Forecaster, the Weather Channel
"That Climate Guy"


View the original article here

Thursday, January 10, 2013

Climate Lottery- Ranking For September 2012

Blog: Climate Lottery: Ranking for September 2012

The lottery pick (or overall National Climatic Data Center Ranking) number for September 2012 came up as 96, the 23rd warmest ranking on record for the lower 48 states for any September since 1895. A ranking of 1 would have been the coldest possible ranking. The National Climatic Data Center has been ranking months, seasons and years from 1 to 118 since 1895 with 1 being the coldest possible temperature average ranking and 118 being the warmest possible temperature average. In the Climate Lottery game, I've defined each individual lottery number as rankings for each month for the lower 48 states, Power Ball numbers as those for each season, and Mega Ball numbers as those for each year. As we keep seeing over and over again the Climate Lottery game is rigged towards those higher number rankings due to global warming. So far, for the contest of fall 2012 Mike Bettes had the closest pick for September, which was 99...good going, Mike!

In September the overall ranking for the lower 48 states was 96 (out of 118):


The jet stream was oriented such that very warm weather persisted in the West with cooler than average temperatures occurring in the Midwest. Nevertheless the overall raking for the U.S. came up as 96...well above the average of 59 and very much in the red as far as rankings go. Looking at the map you can pick out each individual state ranking. Again the overall ranking of 96 is not an average of the 48 individual state rankings; rather the ranking is a comparison of temperature averages for the lower 48 states for September since 1895.

Again, I am getting all of my ranking numbers from the National Climatic Data Center.
The link for the National Climatic Data Center's Climate at a Glance Site where the rankings are archived is: http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html

I'm keeping the format on all of my charts the same as on my previous posts. The average ranking for 2012 is
59 since the coldest ranking would be 1 and the hottest would be 118. I have color coded all rankings for this post at or below 38 blue and all those at or above 79 red with rankings + or -- 19 from the median value of 59 black.

Something very interesting, statistically, is happening this year. Notice that all of the rankings for each individual month have been above 100, so far, except for the month of September in 2012. The probability of eight months in a row being ranked above 100 is extremely small and has never happened before since 1895. We finally had a ranking below 100 for one month of this year, which was in September.

For a more in depth look at temperature statistics see Jon Erdman's article at:

http://www.weather.com/news/drought/record-warm-year-us-september-20121009

For a reference to my last "Climate Dice" post see:

http://www.weather.com/news/climate-dice-sixth-roll-20120912

October 2012 has started out on the cool side. We'll see if this trend continues for the rest of the fall or if the overall warmth of this year continues.

Guy Walton...."That Climate Guy"
Lead Forecaster, the Weather Channel


View the original article here

Wednesday, January 9, 2013

Meteorological images of 2011

Previous editions:
2006
2007
2008
2009
2010


So I guess that makes this the 6th annual!

As I've noted in the introduction the past few years, the content is not meant to represent a complete list of every significant weather event everywhere or images thereof, but there's a lot of stuff which will bring back memories.

This time, in addition to the blog entry, I've also put a selection of a dozen other images into a slide show on weather.com.

In 2011 there were photographs that were so dramatic and widely seen, such as of cars stranded on Lake Shore Drive in Chicago in the February blizzard, and the haboob in Phoenix in July, and the devastation and tragedies caused by the tornadoes and hurricanes and wildfires and drought (and tsunami/earthquakes), and that have been part of other year-in-review features, that I'm not including any photographs here, other than a couple not-so-noteworthy, low-resolution ones that I took myself with a cellphone camera. Instead, I'm going to focus mainly on meteorological imagery and charts; thus this year's title instead of "weather images."

There were plenty of them, as what a year it was. A record number of billion-dollar disasters in the United States, and a lot of meteorological extremes contributing to that. Let's hope for a much less dramatic 2012!

====================

Okay, so I took a photo of a snowy motel parking lot in January. What's the big deal? Well, it not only had personal significance (a harrowing drive to get there that night, and that was to be able to be within walking distance of TWC the following morning), but that relatively little bit of snow compared to what areas farther north experienced last winter was enough to essentially shut down the whole metro Atlanta area for days.


Stu Ostro


Like has been the case so many other times in recent years with precipitation and temperature extremes, the key to the colossal storm in early February which brought a severe blizzard to Chicago was a strong ridge of high pressure aloft (red/orange/yellow shades on the map below, which technically represent above average "500 millibar heights").


NOAA


At the same time of that storm, on the other side of the world was Severe Tropical Cyclone Yasi. In the slide show, I included the image of the "E" in the eye. Here I'm adding another freaky feature in a tropical cyclone eye that it was reminiscent of, a "2" in Hurricane Wilma in 2005.


Naval Research Laboratory; NOAA


Vortices over the Great Lakes in lake-effect snowbands are not rare; TWC severe weather expert Dr. Greg Forbes blogged about them a few years ago and authored a scientific paper on them nearly 30 years ago. However, this, approximately a week after the Groundhog Day blizzard, was a particularly vivid example and included a combo of two.


Gibson Ridge / GRLevel2

A very cold low pressure system aloft, represented by the bright colors on this map depicting temperatures a few miles up, brought snow to parts of the Tucson area in late February after doing so to the higher elevations of San Francisco.


wright-weather.com

This is not meteorological, but it has something in common with weather, as both earthquakes and wind produce waves which can be destructive. This image, which looks like a gigantic bloodshot eyeball, represents a computer model simulation of tsunami waves that were catastrophic in Japan and propagated to other locations all the way across the Pacific.


NOAA

On April 4, a potent weather system brought an astonishing number of severe weather reports (most of them straight-line wind damage). That was a bad omen for the rest of that month ...


NOAA

The next day that system ran out of steam, but as a squall line came through the Miami metro area, a webcam operated by Bryan Norcross, hurricane specialist at TWC, captured this:


Bryan Norcross

A few days later, atmospheric instability represented in the fiery model forecast image below surged way up into Wisconsin, fueling a record-setting tornado outbreak there.


WSI

This was a classic dryline-triggered eruption of thunderstorms that produced tornadoes, including a deadly one in Tushka, Oklahoma the evening of April 14. There were additional casualties in Arkansas as the system moved east overnight.


NASA/GSFC, MODIS Rapid Response (satellite); Gibson Ridge / GRLevel2 (radar)

Then a very energetic stream of wind aloft associated with that system sliced east a couple days later and led to the largest North Carolina tornado outbreak on record.


wright-weather.com


The following Friday, on a flight from Atlanta to Oklahoma City, I observed the atmospheric "cap" breaking. A few hours later a tornado hit Lambert-St. Louis International Airport.


Stu Ostro


The cap broke again on April 27. Dry air aloft as shown in the "water vapor" image on the left can, along with relatively warm air upstairs, put a lid on thunderstorm development. If the lid holds, that's good news. But the energy can build to the point that it explodes sky-high if it can break through the cap/lid. Not only did that happen as shown in the image on the right side, but there was a textbook and extreme set of other ingredients. The outcome: a tornado superoutbreak.


UCAR


I was so stunned to see this extraordinary number and concentration of supercells, many of which had "ground truth" of tornadoes, not just a radar indication of rotation aloft, that I suggested to Dr. Forbes that we should go with a "TOR:CON" index of 10 in northern Alabama, meaning a 100% chance of a tornado within a given spot, and he agreed.


Gibson Ridge / GRLevel2


The Weather Channel


A particularly vivid "debris ball" signature on radar, between Tuscaloosa and Birmingham. Yes, that's not precipitation, it's debris blown by the tornado.


Gibson Ridge / GRLevel2


A swirl of a tropical cyclone wannabe makes landfall on the Mexico coast. What's remarkable about this is that the spin originated from a thunderstorm complex in the Great Lakes during Memorial Day weekend, swung out over the Atlantic Ocean, and then ended up here on the west coast of the Gulf of Mexico a week later!


NASA/GSFC, MODIS Rapid Response

A few days after that, a smoke plume from an Arizona wildfire inferno gets blown by strong winds at sunset.

WeatherTAP (all WeatherTap images used with permission)


Quite a bow echo on radar, and this one was interesting in the way it was moving due north (in southeastern South Dakota).


Gibson Ridge / GRLevel2


During the peak of the summer heat, a meteorological milestone was reached: the big six-oh-oh. 600 decameters is a benchmark value for "500 millibar heights," representative of an extremely strong ridge of high pressure aloft, and the measurement above Omaha the evening of July 17 was close to being a record for that part of the country. The colorful image shows a model forecast for the ridge a few days in advance, and the verification of 600 decameters (6000 meters) was even a bit higher than what was predicted.


wright-weather.com (color map); NOAA via Colorado State University archive (B&W inset)

A few days later, on the northern periphery of the heat ridge, a particularly interesting thunderstorm outflow boundary signature on radar in Minnesota, extending like a long tail well away from the storm cell.


Gibson Ridge / GRLevel2


Tropical Storm Don and its convection croak remarkably rapidly between mid-afternoon and midnight upon arrival in extreme south Texas. Our luck would run out later in the 2011 Atlantic hurricane season ...


Naval Research Laboratory

Although Irene's inner core weakened, sparing places such as the Jersey Shore and New York City from the kind of wind and surge that otherwise would have been experienced, strong upper-level outflow to the northeast helped maintain Irene's low central pressure and overall strength, and that and the cyclone's massive size resulted in widespread wind damage and power outages from North Carolina to New England and contributed to the amount of rainfall which fell.


NOAA

Lee soon followed, and took on an odd appearance on water vapor satellite imagery along the Gulf Coast as dry air wrapped all the way in around the center but then moisture swirled in too.


NOAA

At one point Lee very closely resembled Cindy when it was in a similar position, and both went on to be prolific tornado producers.


Naval Research Laboratory

Lee's remnants and tropical moisture flowed north, and unleashed torrents of rain in the northeastern U.S., much of it occurring in association with long north-south bands of "training," in which individual showers and thunderstorms keep going over the same spot like railroad cars on train tracks. This band persisted all night.


Gibson Ridge / GRLevel2

A map of two-week rainfall which includes what fell from Irene and Lee.


NOAA

In the slide show, I featured a striking satellite image of a swirling "cutoff low," so named because they are completely cut off from the main jet stream. This one persisted in nearly the same place for many days.


NOAA via CSU

And here's another wild-looking water vapor satellite image of it along with another large swirl over the Atlantic Ocean.


WeatherTap


Within an overall large "pressure gradient" and wind field south of a high pressure system in early October, a low pressure system spun up rapidly just offshore of the east coast of central Florida and took on characteristics of a tropical storm.


Gibson Ridge / GRLevel2


That system was part of a repetitive pattern in October that featured low pressure and moisture from the western Caribbean to the subtropical Atlantic, during which, on October 18, there was this cluster of thunderstorms near the Keys, and three days later an exceptionally sharp contrast between dry and moist air aloft.


Both images above: Cooperative Institute for Meteorological Satellite Studies (CIMSS)


A critical factor in causing "Snowtober" to have the impact it did in the Northeast was so much heavy wet snow falling so early in the season, onto trees which still had leaves. Meteorologically the ingredients which came together were just enough cold air from the north meeting up with lots of tropical moisture surging up from the south, all the way from the Caribbean ...


NOAA

... and the interaction of those along with jet stream energy led to a meteorological "bomb," in which there's a drop of at least 24 millibars in 24 hours of central pressure of a cyclone. As this one passed over a buoy east of New England and south of Nova Scotia, the barometer measurement plummeted.


NOAA


Satellite imagery showing the transformation of a disorganized mass of clouds into the cyclonic bomb.


NASA Earth Science Office


This is a common sight in western Oklahoma in spring, not so common in November. This supercell on November 7 produced an EF4 tornado near Tipton, the first tornado on record to get such a high rating in Oklahoma in November.


Gibson Ridge / GRLevel2


At the same time, what was described by the National Weather Service in Alaska as the strongest storm to reach the Bering Sea so far north since 1974 was developing, and during the night of November 8 it resembled a giant ? on satellite imagery.


NOAA

A high-resolution shot of the cyclone's core.


NASA/GSFC, MODIS Rapid Response

Look at the whirlpool that formed in the storm surge in Nome!


KNOM Radio Mission, photographer Matthew Smith; embedded with permission; full-sized image is here


A long nose of cold air dips down at the end of November ...


wright-weather.com


.. as another cutoff low develops, the result being up to 8" of snow reported in Arkansas to the northwest of Memphis, unusually so far south for so early in the season. That November event and Snowtober are quite ironic given the lack of snow in the central and eastern U.S. since then.


UCAR


Yet another cutoff develops, this one with quite a wind flow aloft ...


wright-weather.com


... as well as an exceptionally large (both in magnitude and geographical extent) pressure gradient at the surface, the upshot being a western windstorm which is not only no ordinary Santa Ana, with its effects so widespread in SoCal, but extreme wind gusts occur in spots all the way from there to Steamboat Springs, Colorado.


NOAA

A storm headed for Europe taps moisture from the tropics, resembling a Pacific "Pineapple Express," in this case over the Atlantic ...


NOAA

... but precipitation is not the main impact of this quickly-moving storm, it's wind. A "low-level jet" upwards of 100 mph a few thousand feet up sweeps into France and thereabouts on December 16, with powerful wind gusts blasting down to the Earth's surface.


Plymouth State University Weather Center


Much of the rest of the country was wondering in December, "Where's winter?" Well, it was certainly present in New Mexico. Surreal desolation on a closed I-40 at night was captured by this traffic webcam.


advanced.nmroads.com

What a difference a year makes for what percentage of the country experienced a white Christmas, and where.


NOAA


The turnaround from the past two winters to this one so far was primarily due to the opposite extremity of phenomena known as the AO (Artic Oscillation, shown in this set of graphs) and NAO (North Atlantic Oscillation).


NOAA

That manifested itself in a flip from anomalously strong and persistent ridges of high pressure over and near Greenland during late November and December 2010 (top map) with low pressure aloft to the south, to the reverse in late 2011. The former, an extreme "blocking pattern," led to major snowstorms and persistent cold weather in the central and eastern U.S. and in Europe.


NOAA


Something which is likely a factor contributing to the atmospheric extremity in/near the Arctic in recent years is the precipitous drop in the amount of sea ice there. The black line on this graph plots the volume, which takes into account both the area and thickness of the ice, at the time of the annual minimum each September.

The colored lines represent different mathematical slopes, and what each would do in the future if it were to follow the respective rates of decrease. Although representing different methods and phenomena compared to computer model forecasts of hurricane tracks, this range of projected potential outcomes could be thought of as analogous to the "spaghetti model" plots that have become commonly used.

Hopefully over the coming years and decades the rate of decline showed by the black line will slow down and follow a path toward zero (no ice left in late summer) more like the purple line than the green one. But the recent and current rate is troubling, given the important role that the Arctic and its ice play in the Earth's climate system, and given that this is happening faster than the climate models predicted.


Source and full-sized image: https://sites.google.com/site/arctischepinguin/home/piomas/


On the final day of 2011, Tropical Cyclone Benilde looked scary, but was safely out at sea in the southern Indian Ocean.


Naval Research Laboratory

IMAGES OF THE YEAR

These are my choices for images that were most memorable (other than the indelible photographic ones noted in the introduction) -- not the images themselves, which are simply screen captures of The Weather Channel broadcast and are small in size and not of particularly high resolution, but what they represent in terms of what happened meteorologically and the effects upon those in the storms' paths. In each case it was hard to believe what I was seeing.


Thundersnow experienced live on television by Jim Cantore in Pennsylvania in October?? Yep.


Is that whole seething black mass of cloud extending to the ground a gigantic rotating tornado, live on TV?? Yes, the power flash (bright spot) indicated that it was.

And did a supercell thunderstorm actually spew out debris -- which Jeff Morrow is holding (pieces of shingles and plexiglass) after it fell from the sky -- many miles away from the tornado??

Yes, it did.


Mike Bettes was overcome with emotion upon arriving on the scene in Joplin moments after the EF5 tornado hit.

This high a death toll from a single tornado (and from the April 2011 superoutbreak and other events last year), in the 21st century?? Yes, just as Katrina and the 2004-05 hurricane seasons could be thought of as a wake-up call for our vulnerability to weather even with today's modern forecasting and communication technology, so can 2011 with its tornadoes.


View the original article here