Extreme storms and extreme heat hit the U.S.

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

Share this Blog
40
+

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!

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1005 - 955

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25Blog Index

1005. Levi32
Based on the meridional (north-south) component of the 650mb wind, there is only a weak tropical wave along 38W over the central Atlantic, and there appear to be no well-defined tropical waves over the African continent at this time (maybe a very low-amplitude one at 10W), so the prospects are rather low in the near future of a potent tropical wave coming westward and needing to be watched for tropical development.

Member Since: Posts: Comments:
Quoting PlazaRed:

MOVE!


Not a bad idea, she might end up going to the smae college so there is hope there.

Quoting spathy:


Doesnt look too solid a line yet. How fast is that moving?


About 40 MPH, but it is slightly accelerating.
Member Since: Posts: Comments:
Thanks Caicos...I couldn't get it to post with this phone
Member Since: Posts: Comments:
Quoting WxGeekVA:


I had this girl I met at weather camp last year at Penn State. I wish she didn't live halfway across the country, because if she lived closer, I would ask her out (to stormchase! :P) Plus she already told me that she would if I was closer too.

MOVE!
Member Since: Posts: Comments:
Does anybody think the line of storms over Ohio will affect the area between York, PA and Baltimore, MD later tonight?
Member Since: Posts: Comments:


Uh Oh.... Please not again....
Member Since: Posts: Comments:
There's a HUGE difference between making some wrong statements/predictions about the weather along with other offbeat comments and trolling. And ilovehurricanes13 hasn't been trolling recently, Tribucanes, not under that name.
Maybe never has; I suspect s/he isn't who you think it is.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
996. VR46L
Quoting Tribucanes:
Sweet VR46L, about a quarter of the members of WU it seems like are female. Women multitask so well they often excel in the meteorology field. Not to mention women are now exceeding men in the math and science fields in America. And often it's the same reason men get into the field; some childhood weather event that stuck with them and got them interested. A woman interested in and articulate and informed in meteorology is an attractive quality; just saying.


Why thank you Sir...Most kind of you to say so
Member Since: Posts: Comments:
Quoting Tribucanes:
Sweet VR46L, about a quarter of the members of WU it seems like are female. Women multitask so well they often excel in the meteorology field. Not to mention women are now exceeding men in the math and science fields in America. And often it's the same reason men get into the field; some childhood weather event that stuck with them and got them interested. A woman interested in and articulate and informed in meteorology is an attractive quality; just saying.


I had this girl I met at weather camp last year at Penn State. I wish she didn't live halfway across the country, because if she lived closer, I would ask her out (to stormchase! :P) Plus she already told me that she would if I was closer too.
Member Since: Posts: Comments:


Presslord's "here IT comes" Photo
Member Since: Posts: Comments:
Quoting GeorgiaStormz:


i wonder if the next heat wave will break atlantas new 106F record

btw my AC is working again thank god

Man!
You ain't seen nothing yet!
Member Since: Posts: Comments:
Happy B-Day Grothar! Out of respect, will keep all jokes to myself :)
Member Since: Posts: Comments:
Quoting gulfbreeze:
What will happen to the storms in NC after they reach the Atlantic and the Gulf Stream? Any chance for trop. dev.?


its happened before..it moved to Florida as a TD I believe last year..one of Reed's finest hour
Member Since: August 19, 2006 Posts: 13 Comments: 14439
There's been a little cluster of very shallow(1 mile deep or less around M4 earthquakes in the Baja and relatively shallow ones(20 deep) in the M4-5 repeatedly "off the East Coast near Honshu, Japan"...which are stronger. In the last day or 2.
Link
Member Since: August 3, 2005 Posts: 10 Comments: 5526
Quoting hydrus:
I did not think 13 was a troll. I would not have posted..
jason.gets.a.bad.rap.that.character.has.carried.t his.blog.on.its.sholder.in.slow.times
Member Since: Posts: Comments:
For those interested:

Radiation goes wherever the weather patterns a and the wind blows....

Arnie Gundersen on CCTV: Three Mile Island, Chernobyl, Fukushima Daiichi: What is the Link?

CCTVs Margaret Harrington
June 27, 201

Link
Member Since: Posts: Comments:
Sweet VR46L, about a quarter of the members of WU it seems like are female. Women multitask so well they often excel in the meteorology field. Not to mention women are now exceeding men in the math and science fields in America. And often it's the same reason men get into the field; some childhood weather event that stuck with them and got them interested. A woman interested in and articulate and informed in meteorology is an attractive quality; just saying.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
I had another 'Singing in the rain' moment. I wasn't expecting to get any rain today, but it turns out a nice thunderstorm formed right over my house. :-D
Member Since: August 9, 2009 Posts: 10 Comments: 4898
Quoting beell:
my ducks are quick, quick, quicking for rain also
Quick ducks can be a problem.
Member Since: August 3, 2005 Posts: 10 Comments: 5526
983. VR46L
Quoting hydrus:
Yes sir. If its as bad as it looks, there is serious trouble down there.


Yep dont look good ..BTW I am a Female....LOL
Member Since: Posts: Comments:
I figured as much hydrus, he's been here for the better part of the week; have no idea why he hasn't been kicked again. Maybe they know he will come back immediately. So they let him stay now as is; we just all know it now and can ignore. Would sound smart to me if he's just going to come back anyway. Ya you rock hydrus, I was like this Troll is sending people off.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
981. beell
my ducks are quick, quick, quicking for rain also
Member Since: Posts: Comments:
Quoting VR46L:
there are some serious big blobs coming through the Mid Atlantic States at the moment..Be Careful folks


Yes sir. If its as bad as it looks, there is serious trouble down there.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting Tribucanes:
Hydrus why in the world are you quoting the world's largest known troll? Hurricane13 is Jason, the known troll of WU. No one please open any of his crude, sad, little, comments. He feeds off it big time. If no one quotes, reads, pays any attention to; then the attentions seeker has no attention. Give him NONE, that's the only thing that feeds this little, mean, petty, inappropriate git.
I did not think 13 was a troll. I would not have posted..
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting Grothar:


Isn't is funny, my birthday July 1, is the same as Canadian Independence day. :)


Happy Birthday Sensei,
Member Since: Posts: Comments:
Quoting GeorgiaStormz:


i wonder if the next heat wave will break atlantas new 106F record

btw my AC is working again thank god
No..The next one is further west and stays there. I wish it was us, for the sake those folks over there. I really do not think that area can handle anymore.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
I know you were trying to be funny hydrus
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Hydrus why in the world are you quoting the world's largest known troll? Hurricane13 is Jason, the known troll of WU. No one please open any of his crude, sad, little, comments. He feeds off it big time. If no one quotes, reads, pays any attention to; then the attentions seeker has no attention. Give him NONE, that's the only thing that feeds this little, mean, petty, inappropriate git.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Quoting aspectre:
923 KEEPEROFTHEGATE:

Kelvin–Helmholtz instability over the Appalachians?
No. Floodman exhaling.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Quoting hydrus:
A little warm for mine too. 107 Friday 106 Saturday 104 today....I am ready for a cold front or some rain.


i wonder if the next heat wave will break atlantas new 106F record

btw my AC is working again thank god
Member Since: Posts: Comments:
ABNT20 KNHC 012317
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT SUN JUL 1 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS.

$$
FORECASTER PASCH

ABPZ20 KNHC 012318
TWOEP

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
500 PM PDT SUN JUL 1 2012

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS.

$$
FORECASTER PASCH
Member Since: October 15, 2011 Posts: 0 Comments: 4004
971. VR46L
there are some serious big blobs coming through the Mid Atlantic States at the moment..Be Careful folks


Member Since: Posts: Comments:
923 KEEPEROFTHEGATE:

Kelvin-Helmholtz instability over the BlueRidgeMountains?
Member Since: August 21, 2007 Posts: 0 Comments: 4860
What will happen to the storms in NC after they reach the Atlantic and the Gulf Stream? Any chance for trop. dev.?
Member Since: Posts: Comments:
Quoting GeoffreyWPB:
The big picture...



Is normal to see this picture in July but after all the tropical activity that we have seen in past weeks to suddenly turn very quiet looks errie.If anyone wants to comment about what to expect in July, you can visit my blog.



Link
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting ilovehurricanes13:
hot weather for my dicks today over 100F
A little warm for mine too. 107 Friday 106 Saturday 104 today....I am ready for a cold front or some rain.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Third line slowly gaining momentum in Southern Minnesota and will try to gets it's act together and impact South Central Wisconsin, but dew point and humidity remain low here in Wisconsin. Lack of instability may make this third line unable to do much more than it's doing now I think. We need the rain so bad in South and South Central Wisconsin, but I'm skeptical that we'll get much from this. Maybe tomorrow, but I guess careful what you wish for with this heat induced SW.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Member Since: Posts: Comments:
to me the storm cluster in nw ohio is looking pretty mean right now..
Member Since: Posts: Comments:
You know its bad as far as power outages when the actual power company is experiencing their own power outages..

Public Information (New Hanover County)
@progressenergy No more real time updates via outage map? Major loss for Emerg. Mgmt
Member Since: August 19, 2006 Posts: 13 Comments: 14439
960. VR46L
Quoting wunderkidcayman:
hey guys just popping in to say that: there seem to be a surface low level circulation forming in the extreme SE caribbean, this is according to surface obs, ASCAT, and vort map at 850 and 925mb. there is convection in the area and in the upper levels, there is a upper level anticyclone in the area causing 10-20kt of shear and it is dropping. so I am just noting that and its just something to keep one eye on. hey maybe its EX-97L trying to make a comeback but this is all I am sayin


If I was living in the Caymans I would be hoping any invest dies a death before it makes it to the Herbert Boxes...but I guess each to their own...and if it becomes an invest I will be eating crow
Member Since: Posts: Comments:
Quoting WxTracker15:
That is a wild image..Looks like a Hubble pic.:)
Member Since: September 27, 2007 Posts: 1 Comments: 20493
The big picture...

Member Since: Posts: Comments:
Quoting aspectre:
Remind you of anyone?
My brothers wife.
Member Since: September 27, 2007 Posts: 1 Comments: 20493
Ya Packman lot of similarities.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
I see why the SPC couldn't put out at least a moderate warning, it would have been for a thousand mile stretch from the Carolina's all the way to Central Illinois. Would have looked wild and threatening though; and this day has been that again.
Member Since: April 18, 2012 Posts: 0 Comments: 2437

Viewing: 1005 - 955

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.