Extreme storms and extreme heat hit the U.S.

By: Dr. Jeff Masters , 5:50 PM GMT on June 30, 2012

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A violent line of organized severe thunderstorms called a derecho swept across the U.S. from Illinois to Virginia on Friday, damaging houses, toppling trees, bringing down power lines. The storms killed six people in Virginia, two in New Jersey, and one in Maryland, and left at least 3.4 million people without power. The thunderstorms in a derecho (from the Spanish phrase for "straight ahead") create violent winds that blow in a straight line. The traditional definition of a derecho is a thunderstorm complex that produces a damaging wind swath of at least 240 miles (about 400 km), featuring a concentrated area of thunderstorm wind gusts exceeding 58 mph (93 km/hr.) A warm weather phenomenon, derechos occur mostly in summer, especially June and July in the Northern Hemisphere. They can occur at any time of the year and occur as frequently at night as in the daylight hours. As seen on our wundermap with the "go back in time" feature turned on, Friday's derecho began near Chicago in the early afternoon, then marched east-southeast, peaking in intensity over Virginia and Washington D.C. on Friday evening. The derecho was unusually intense due to the extreme heat, which helped create an unstable atmosphere with plenty of energy to fuel severe thunderstorms.


Figure 1. Radar image from our wundermap with the "go back in time" feature turned on for 11 pm EDT Friday June 29, 2012, showing the derecho over Washington D.C. and Baltimore. Click on the "hour" button above the wundermap to advance the time by one hour to watch the progress of the derecho across the country.


Figure 2. NOAA's Storm Prediction Center (SPC) logged 871 reports of damaging winds on Friday. Twenty one of these reports were for winds over 80 mph. The highest wind gust was in Oswego, Illinois: 92 mph.



Figure 3. A dramatic change in the weather in Buckeye land: the temperature at Ohio State University in Columbus, Ohio dropped from 97°F to 68° after passage of Friday's derecho. The storm brought a wind gust of 82 mph to campus, and 0.86" of rain.

Historic heat wave topples Dust Bowl-era extreme heat records
A historic heat wave on a scale and intensity not seen in the U.S. since the great heat waves of the 1930s Dust Bowl era set new all-time heat records for at least ten major cities Friday. According to wunderground's weather historian Christopher C. Burt, fifteen of the 303 major cities he maintains records for on the wunderground extremes page have set all-time heat records in the past four days. The only year with more all-time heat records is 1936, when 61 cities set all-time heat records. In 2011, which had the 2nd warmest summer in U.S. history, only ten of the 303 cities set all-time heat records during the entire summer. With the the hottest month of the year (July) still to come, 2012 threatens to rival the great Dust Bowl summer of 1936 for extreme heat.

All-time records for any date tied or broken on Friday:

109° Nashville, TN (old record 107° 7/28/1952
109° Columbia, SC (old record 107° on two previous occasions)
109° Cairo, IL (old record 106° on 8/9/1930)
108° Paducah, KY (ties same on 7/17/1942
106° Chattanooga, TN (ties same on 7/28/1952)
105° Raleigh, NC (ties same on 8/21/2007 and 8/18/1988)
105° Greenville, SC (old record 104° 8/10/2007 although 106° was recorded by the Signal Service in July 1887)
104° Charlotte, NC (ties same on 8/9 and 10/2007 and 9/6/1954)
102° Bristol, TN (ties same on 7/28/1952-this site now known as `Tri-State Airport')
109° Athens, GA. This is just 1° shy of the Georgia state record for June of 110° set at Warrenton in 1959.

All-time state June heat records set Friday:

113° Smyrna, TN (old record 110° in Etowah in June 1936)
109° Cairo, IL (old record 108° in Palestine in June 1954)

Also of note: Atlanta, GA hit 104° (its all-time June record), and just 1° shy of its all-time record of 105° set on 7/17/1980. The forecast for Atlanta on Saturday calls for a high of 105°F, which would tie for the hottest day in the city's history.

Wunderground's weather historian Christopher C. Burt has a new post called The Amazing June Heat Wave of 2012 Part 1: The West and Plains June 23 - 27 summarizing the early portion of this week's historic heat wave. He plans to make a follow-up post on Sunday summarizing the records set on Friday and Saturday.

Relatively quiet in the Atlantic
An area of heavy thunderstorms, associated with an upper level low pressure system, has developed in the Gulf of Mexico along the Texas coast. This disturbance will probably move ashore over Texas before development into a tropical depression can occur, and NHC is giving it a 0% chance of development. The tropical wave approaching the Lesser Antilles (Invest 97L) has dissipated due to dry air, and is no longer a threat. None of the reliable computer models are developing anything during the next seven days.

Jeff Masters

Chicago Shelf (LarrySmit)
Chicago Shelf
Summer Heat (gardner48197)
Summer Heat
Smokey Clouds (LarrySmit)
Asperatus Clouds
Smokey Clouds
And the Sky Opened Up! (webgal)
Much needed thunderstorms came through west-central Illinois late this evening. The lightning was absolutely incredible!
And the Sky Opened Up!

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Quoting Tribucanes:
If this heat doesn't subside in the next three to five weeks, it will be the story driving a lot of weather blogs I would think. Is another high going to replace the one doing this crap now? Long term is miserable for upper Midwest too, it's miserable here in Wisconsin. Long term forecast to be ninety to ninety five for the next seven to fourteen. Wonder if it'll break after that?

The GFS shows this one slowly fading at the same time another one develops across the Northern Plains. It moves that one east into the Northeast with time.

This heatwave will be around for at least the next 10 days.
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Quoting Tazmanian:



ok


but it was all ready re move by the admins sorry about that


WUmail me describing it or something i just kinda missed it. dont know what happened
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If this heat doesn't subside in the next three to five weeks, it will be the story driving a lot of weather blogs I would think. Is another high going to replace the one doing this crap now? Long term is miserable for upper Midwest too, it's miserable here in Wisconsin. Long term forecast to be ninety to ninety five for the next seven to fourteen. Wonder if it'll break after that?
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Quoting weatherh98:


mo just what wasit lol



ok


but it was all ready re move by the admins sorry about that
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Quoting hydrus:
96 degrees with the humidity in the 80,s sounds almost deadly..

It was 92 here today with humidity hovering close to 70%. Not too far from that...
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Quoting Tazmanian:



NO it was all ready re move


mo just what wasit lol
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Quoting stormchaser19:

they don't banned me, they just delete the message

what was it?
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Quoting weatherh98:


can you WU mail me what it was?



NO it was all ready re move
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Quoting Tazmanian:






i hop you like the 24hr ban the admins will give you


so i would re move that or get ban by the admins


can you WU mail me what it was?
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Quoting wunderkidcayman:
hey guys sorry for being away for about an hour had to run off for something

anyway say what you would like but what happen if they put out another ATCF plots on 97L and for the rest of you guys that say it is dead what if the reactivated 97L again?
and what if 97L redevelops convection and shear doesen't look all that bad anymore then what?




there is no LOW with 97L 97L was olny a open wave


plzs post somee in too back up your statment



97L is dead
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hey guys sorry for being away for about an hour had to run off for something

anyway say what you would like but what happen if they put out another ATCF plots on 97L and for the rest of you guys that say it is dead what if the reactivated 97L again?
and what if 97L redevelops convection and shear doesen't look all that bad anymore then what?
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NHC nailed Debby's exit stage right impressively. She went post-tropical when NHC said she would. Maybe they downplayed her winds by five or so, but they did fine. Debby still was a pretty system to watch with a well defined center, just void of all convection and almost all the moisture at that time. Like a Tropical Storm in appearance in some ways though with TS winds, will be interesting how they classify it later. I think I said numerous times it could re=fire and develop. I'm an enthusiast, glad we have the pros.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
am gussing the NWS is not the olny ones have bugs today




what is up with the blogs today
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Quoting Tazmanian:
ooops looks like he got a 24hr ban



so i guss my warning was too late


they don't banned me, they just delete the message
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Noctiluminescent clouds from Fife over the Forth(railway)Bridge
(which connects to Fife to Edinborough,Scotland)
Member Since: August 21, 2007 Posts: 0 Comments: 4860
I had a question about Debby if Debby had moved to the west the wind shear would not had killed her more rapidly than when she moved to the east?Because I know that at the time there was an upper level low causing wind shear.
Member Since: October 15, 2011 Posts: 0 Comments: 3952
Quoting bohonkweatherman:
Yes but Alaska's weather has its negatives also, like Winter!


I'll take the winter part. Juneau isn't too bad. Anchorage is like Duluth.
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Quoting Tazmanian:
ooops looks like he got a 24hr ban



so i guss my warning was too late

they don't banned me, they just delete the message
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Quoting MAweatherboy1:
Bust on the severe threat today... Atmosphere remains too stable from yesterday...



too early to call...
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RECORD EVENT REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
0432 PM EDT SAT JUN 30 2012

...RECORD ALL-TIME HIGH TEMPERATURE SET AT ATLANTA...

A RECORD HIGH TEMPERATURE OF 106 DEGREES WAS SET AT ATLANTA SO FAR
TODAY. THIS BREAKS THE ALL-TIME HIGH TEMPERATURE RECORD FOR ATLANTA
OF 105 SET IN 1980. THE OLD DAILY RECORD OF 98 WAS SET ON JUNE 30TH
IN 1936.
---------------------------

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
0432 PM EDT SAT JUN 30 2012

...RECORD ALL-TIME HIGH TEMPERATURE SET AT COLUMBUS...

A RECORD HIGH TEMPERATURE OF 106 DEGREES WAS SET AT COLUMBUS SO FAR
TODAY. THIS BREAKS THE PREVIOUS ALL-TIME HIGH TEMPERATURE RECORD OF
105 SET AT COLUMBUS YESTERDAY. THE OLD DAILY RECORD OF 100 WAS SET
ON JUNE 30TH IN 1959.
----------------------------

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
0432 PM EDT SAT JUN 30 2012

...RECORD ALL-TIME HIGH TEMPERATURE TIED AT MACON SO FAR TODAY...

A RECORD HIGH TEMPERATURE OF 108 DEGREES WAS OBSERVED AT MACON SO
FAR TODAY. THIS TIES THE ALL-TIME HIGH TEMPERATURE RECORD OF
108...LAST OBSERVED IN 1980...AND BREAKS THE OLD DAILY RECORD OF 103
SET ON JUNE 30TH IN 1959.
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what is up with this site today it seem like the nws is not the olny one haveing bugs today
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Sorry for double post.
Member Since: August 9, 2009 Posts: 10 Comments: 4888
Quoting bohonkweatherman:
Yes but Alaska's weather has its negatives also, like Winter!




i i think Alaska sould have it own season



like it would be summer here in are part of the uesa but up in Alaska it would be fall or some in
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24 hours. I would think that deserves a perma-band. Taz you are being quite nice for such a crime. Sic'em!!! ;-)

BTW, Are there any signs of a new line of storms, (derecho II) like last night's round, starting up yet?
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Member Since: August 19, 2006 Posts: 13 Comments: 14245
ooops looks like he got a 24hr ban



so i guss my warning was too late
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@222 see ya later friend ;)
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Quoting stormchaser19:
Weather Report of the day







i hop you like the 24hr ban the admins will give you


so i would re move that or get ban by the admins
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@222 While I chuckled and heartily agree it's also a family blog. You might want to take that down or rephrase it.
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Quoting stormchaser19:
Weather Report of the day


omg....well it was nice knowing you....
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Quoting Tazmanian:
you guys sould moved too Alaska


right now Alaska is like fall with highs in the 50s and low in the 40s with a ch of rain all most ever day
Yes but Alaska's weather has its negatives also, like Winter!
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Quoting SubtropicalHi:


We got 0 in San Antonio. Storms fizzled as they approached town.

Same happened yesterday.

Yep High Pressure is Killing the Rains in Texas, only those close to Coast are getting decent rains, they move west and hit high pressure and evaporate. Just like that Tropical Storm that Hit Texas last year and gave me blowing dust even though NWS gave me a 60 percent chance of rain. Don't mess with Texas and High pressure systems, they will kick your behind.
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you guys sould moved too Alaska


right now Alaska is like fall with highs in the 50s and low in the 40s with a ch of rain all most ever day
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Quoting bohonkweatherman:
First day of any rain here in 46 days, received less than .10 but it did not hit 100, in Texas that is a great day!


We got 0 in San Antonio. Storms fizzled as they approached town.

Same happened yesterday.

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Quoting hydrus:
96 degrees with the humidity in the 80,s sounds almost deadly..
Can you Say Suckville? That is Texas in the Summer, of course i have only been here 50 years and La. for 4 years but Summers in Texas are not for Humans or Animals and Yes every year we are getting Hotter. If it isnt 105 to 110 it is 96 to 100 with Heat indexes off the chart. Yesterday I had blowing dust, today i got the roads wet. You kind of get use to it but it doesnt mean I have to like it. One of the Worst Heatwaves ever in the USA and we are not in July yet, what will July and August have in store. It hit 109 here already, usually those temps happen at the End of Summer then it cools off but not in June? I am hoping El Nino kicks in full blast and gives some parts of the U.S. a break later in the Summer. El Nino means rain for Texas I know that much
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It's so hot you can wash and dry your clothes at the same time.
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Quoting GTcooliebai:
BOOO!!! Your jokes stink, j/k...yeah it is hot and humid, I go outside to work on my car and instantly I start sweating.


LOL..I know!!!..I need a storm to track..
Member Since: August 19, 2006 Posts: 13 Comments: 14245
Quoting bohonkweatherman:
96 here with humidity in the 80s. I think next Summer I will go to Seattle for a break and do that every Summer, will be a nice break from 100 to 110 pounding Central Texas takes
96 degrees with the humidity in the 80,s sounds almost deadly..
Member Since: September 27, 2007 Posts: 1 Comments: 20328
Quoting TropicalAnalystwx13:
The wave train is setting up quite nicely for this time of the yr. I'm ready to track some real action in the MDR.
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Quoting ncstorm:
It's so hot today..the National Weather Service has issued a fat guy in tank top warning....
BOOO!!! Your jokes stink, j/k...yeah it is hot and humid, I go outside to work on my car and instantly I start sweating.
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It's so hot today..the National Weather Service has issued a fat guy in tank top warning....
Member Since: August 19, 2006 Posts: 13 Comments: 14245
Quoting ncstorm:
How hot is it?

I saw Optimus Prime transform into an air conditioner..

da da da!!


*throws tomato*
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How hot is it?

I saw Optimus Prime transform into an air conditioner..

da da da!!

Member Since: August 19, 2006 Posts: 13 Comments: 14245
Quoting hurricanehunter27:
At 3:51 we reached a temp of 106 and was still climbing. I am guessing the 4:51 reading will be around 110-108. Humidity is still 25%.
105 degrees here right now. They keep talking about how powerful this high pressure cell is.. Barometer is at 29.82 inches and falling...go figure..
Member Since: September 27, 2007 Posts: 1 Comments: 20328
207. redux
i got caught outside in the derecho. it was crazy. lots of trees down. i wanted it to rain so bad to cool everything off.

didn't lose power in baltimore city, but my brother said he had to drive 10 miles to find a cup of coffee this morning.
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Quoting txjac:


Got .72 inch here and low temps ...nice day
96 here with humidity in the 80s. I think next Summer I will go to Seattle for a break and do that every Summer, will be a nice break from 100 to 110 pounding Central Texas takes
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Quoting txjac:


Got .72 inch here and low temps ...nice day
System too far south to do much of Texas any good, unfortunately High Pressure is moving back in by Monday.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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