Dr. Jeff Masters' WunderBlog

Extreme storms and extreme heat hit the U.S.

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

+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)

Summer Heat (gardner48197)

Smokey Clouds (LarrySmit)

Asperatus Clouds

And the Sky Opened Up! (webgal)

Much needed thunderstorms came through west-central Illinois late this evening. The lightning was absolutely incredible!

Categories: Extreme Weather Heat

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1051. AussieStorm 1:41 AM GMT on July 02, 2012
Quoting Ameister12: Anybody here? Yep, I'm here. A balmy 58.3°F after an overnight low of 39°F. Member Since: September 30, 2007 Posts: 5 Comments: 13262

1052. washingtonian115 1:44 AM GMT on July 02, 2012
Ah stick'in great another nasty line of storms coming my way... Quoting VAbeachhurricanes: Wind: Hail: What day is that for?. Member Since: August 14, 2010 Posts: 5 Comments: 10585

1053. Ameister12 1:44 AM GMT on July 02, 2012
Quoting AussieStorm: Yep, I'm here. A balmy 58.3°F after an overnight low of 39°F. Hey, Aussie. How you doing? Member Since: August 9, 2009 Posts: 9 Comments: 3421

1054. aspectre 1:44 AM GMT on July 02, 2012
995 WxGeekVA: ...this girl I met at weather camp last year at Penn State. I wish she didn't live halfway across the country... 1011 WxGeekVA: I'm going out stormchasing next spring there, so I want to hang with her then. I hope it works out, I like everything about her. Sucks I only got to hang for a week last time. Just remember, "...brains... I want your brains... brains..." ain't a good pickup line. Member Since: August 21, 2007 Posts: 0 Comments: 4846

1055. TropicalAnalystwx13 1:49 AM GMT on July 02, 2012
Not sure if this has been posted yet, so I'll post it again. I found it funny. Member Since: July 6, 2010 Posts: 89 Comments: 25128

1056. AussieStorm 1:49 AM GMT on July 02, 2012
Quoting Ameister12: Hey, Aussie. How you doing? other than cold, drinking a cuppa tea, also looking after 3 kids as it's school holidays and dealing with to many health problems, I'm 100% perfect. How are you? Member Since: September 30, 2007 Posts: 5 Comments: 13262

1057. WxGeekVA 1:50 AM GMT on July 02, 2012
Quoting aspectre: 995 WxGeekVA: ...this girl I met at weather camp last year at Penn State. I wish she didn't live halfway across the country... 1011 WxGeekVA: I'm going out stormchasing next spring there, so I want to hang with her then. I hope it works out, I like everything about her. Sucks I only got to hang for a week last time. Just remember, "Brains. I want your brains. Brains..." ain't a good pickup line. Unless you're a zombie.. and I think I see what you did there... Member Since: September 3, 2011 Posts: 13 Comments: 3311

1058. WxGeekVA 1:52 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Not sure if this has been posted yet, so I'll post it again. I found it funny. I'm going to guess 634/49 for Wednesday. The GFS Ensembles agree with me. Member Since: September 3, 2011 Posts: 13 Comments: 3311

1059. presslord 1:54 AM GMT on July 02, 2012
Quoting aspectre: 995 WxGeekVA: ...this girl I met at weather camp last year at Penn State. I wish she didn't live halfway across the country... 1011 WxGeekVA: I'm going out stormchasing next spring there, so I want to hang with her then. I hope it works out, I like everything about her. Sucks I only got to hang for a week last time. Just remember, "Brains. I want your brains. Brains..." ain't a good pickup line. and remember: whenever you see a really hot girl...some guy somewhere is just sick of her crap Member Since: August 13, 2007 Posts: 0 Comments: 10377

1060. AussieStorm 1:55 AM GMT on July 02, 2012
Quoting presslord: and remember: whenever you see a really hot girl...some guy somewhere is just sick of her crap speaking from experience? When you coming to pick up this 1.125L of Jim Beam Black, it won't drink itself. Member Since: September 30, 2007 Posts: 5 Comments: 13262

1061. Ameister12 1:58 AM GMT on July 02, 2012
Quoting AussieStorm: other than cold, drinking a cuppa tea, also looking after 3 kids as it's school holidays and dealing with to many health problems, I'm 100% perfect. How are you? Health problems? That's fantastic (sarcasm). Well, It's been extremely hot and the rain we got today and Friday isn't helping, so I've been cooped up in my house all week and I'm bored. Typical summer in Ohio. Member Since: August 9, 2009 Posts: 9 Comments: 3421

1062. DataPilot 1:59 AM GMT on July 02, 2012
Quoting aspectre: 995 WxGeekVA: ...this girl I met at weather camp last year at Penn State. I wish she didn't live halfway across the country... 1011 WxGeekVA: I'm going out stormchasing next spring there, so I want to hang with her then. I hope it works out, I like everything about her. Sucks I only got to hang for a week last time. Just remember, "Brains. I want your brains. Brains..." ain't a good pickup line. That's an AWESOME pickup line. It would have worked on me! (I'm a girl-geek.) @WxGeekVA, give it a shot. Here in Eugene, Oregon, we have 68F and yet more drizzle. That's rotten weather for making hay, which I badly need. But after reading about the heat and storms back East, I'm not kvetching about the drizzle. Besides, cool temps and a little drizzle are not bad for the Track and Field Olympic Trials, which are finishing up right now. Member Since: January 5, 2009 Posts: 9 Comments: 1035

1063. presslord 1:59 AM GMT on July 02, 2012
Quoting AussieStorm: speaking from experience? When you coming to pick up this 1.125L of Jim Beam Black, it won't drink itself. soon...pinned down at the moment by horrile lightening Member Since: August 13, 2007 Posts: 0 Comments: 10377

1064. KoritheMan 2:00 AM GMT on July 02, 2012
Quoting DataPilot: That's an AWESOME pickup line. It would have worked on me! (I'm a girl-geek.) @WxGeekVA, give it a shot. Here in Eugene, Oregon, we have 68F and yet more drizzle. That's rotten weather for making hay, which I badly need. But after reading about the heat and storms back East, I'm not kvetching about the drizzle. Besides, cool temps and a little drizzle are not bad for the Track and Field Olympic Trials, which are finishing up right now. Kvetching? Seriously? slow clap Member Since: March 7, 2007 Posts: 408 Comments: 15417

1065. goosegirl1 2:01 AM GMT on July 02, 2012
Quoting WxGeekVA: Uh Oh Not Good... Just west of where I live too... I'm right in the middle, hoping for the best. They don't look quite as bad as Friday's storms. I just read a report of a confirmed downburst 30 yards wide and one mile wide, with winds at 100 mph near Reedsville WV. We really don't need a repeat. Member Since: December 17, 2009 Posts: 0 Comments: 852

1066. washingtonian115 2:02 AM GMT on July 02, 2012
Does anybody know what date that is for the server weather event in comment 1037. Member Since: August 14, 2010 Posts: 5 Comments: 10585

1068. goosegirl1 2:09 AM GMT on July 02, 2012
Quoting washingtonian115: Does anybody know what date that is for the server weather event in comment 1037. Unfortunately, that's for tonight, after midnight. Here it comes again: ( Member Since: December 17, 2009 Posts: 0 Comments: 852

1069. goosegirl1 2:11 AM GMT on July 02, 2012
Quoting goosegirl1: Unfortunately, that's for tonight, after midnight. Here it comes again: ( Sorry, forgot to say check on noaa.gov severe storm page to get more info. Member Since: December 17, 2009 Posts: 0 Comments: 852

1070. washingtonian115 2:11 AM GMT on July 02, 2012
Quoting goosegirl1: Unfortunately, that's for tonight, after midnight. Here it comes again: ( Wha?.Noooooooooo.People can't go through this again.Nature..I'm starting to hate you... Member Since: August 14, 2010 Posts: 5 Comments: 10585

1071. KoritheMan 2:14 AM GMT on July 02, 2012
Can anybody say... doom? Member Since: March 7, 2007 Posts: 408 Comments: 15417

1072. Ameister12 2:15 AM GMT on July 02, 2012
Quoting KoritheMan: Can anybody say... doom? Nope. Nobody can. Member Since: August 9, 2009 Posts: 9 Comments: 3421

1073. WxGeekVA 2:17 AM GMT on July 02, 2012
It looks weaker, but Friday's did too for a while. I'll be watching it as it goes over the mountains. Member Since: September 3, 2011 Posts: 13 Comments: 3311

1074. jpritch 2:22 AM GMT on July 02, 2012
Hail from a couple of hours ago in Chillicothe, Ohio. Member Since: June 28, 2007 Posts: 0 Comments: 291

1075. washingtonian115 2:23 AM GMT on July 02, 2012
Me and hubby have been busy all afternoon long.We've taken some neighbors that don't have power to cooling centers(Lucky I have a van).Hopefully power is restored to them soon. Member Since: August 14, 2010 Posts: 5 Comments: 10585

1076. Skyepony (Mod) 2:23 AM GMT on July 02, 2012
That's big hail... Member Since: August 10, 2005 Posts: 144 Comments: 29236

1078. KoritheMan 2:25 AM GMT on July 02, 2012
Quoting washingtonian115: Me and hubby have been busy all afternoon long.We've taken some neighbors that don't have power to cooling centers(Lucky I have a van).Hopefully power is restored to them soon. How considerate of you. :) Member Since: March 7, 2007 Posts: 408 Comments: 15417

1079. VirginIslandsVisitor 2:30 AM GMT on July 02, 2012
Quoting GeoffreyWPB: Happy Birthday Gro... lol Good one Geoffrey....and a Happy b'day to you, Grothar!! Other than two 50-drop showers today, my mango tree is dropping more fruit than water. We could really handle some decent rain over here. Lindy Member Since: July 30, 2011 Posts: 0 Comments: 234

1080. TropicalAnalystwx13 2:31 AM GMT on July 02, 2012
Quoting KoritheMan: Can anybody say... doom? Doom. Member Since: July 6, 2010 Posts: 89 Comments: 25128

1081. KoritheMan 2:32 AM GMT on July 02, 2012
It's Grothar's bday? Happy... how many does this make? Is three trillion a fair estimate? Member Since: March 7, 2007 Posts: 408 Comments: 15417

1082. washingtonian115 2:32 AM GMT on July 02, 2012
Quoting KoritheMan: How considerate of you. :) When it comes to disasters like this as a community we have to pull together.That's what makes us better in the future.Americans have always pulled together in these types of situations.It's the american spirit. Member Since: August 14, 2010 Posts: 5 Comments: 10585

1083. KoritheMan 2:33 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Doom. Imagine the ACE such a storm would have. Member Since: March 7, 2007 Posts: 408 Comments: 15417

1084. TropicalAnalystwx13 2:34 AM GMT on July 02, 2012
Quoting KoritheMan: Imagine the ACE such a storm would have. 103.76 units. Member Since: July 6, 2010 Posts: 89 Comments: 25128

1085. KoritheMan 2:35 AM GMT on July 02, 2012
Quoting washingtonian115: When it comes to disasters like this as a community we have to pull together.That's what makes us better in the future.Americans have always pulled together in these types of situations.It's the american spirit. If I get an opportunity to chase a major hurricane this year (Debby sucked), I will make sure to help the victims in any way I can. I think I'd go home feeling guilty otherwise. Member Since: March 7, 2007 Posts: 408 Comments: 15417

1086. Ameister12 2:35 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Doom. 1.7 trillion dollars in damage? Holy @!%! Member Since:* August 9, 2009 Posts: 9 Comments: 3421

1087. RTSplayer 2:35 AM GMT on July 02, 2012
Man what the heck? Are we going to get ANOTHER land-cane move off shore and become tropical over the next few days? Hard to imagine the mass of convection moving through Georgia and the Carolinas NOT holding together over land and water. Speaking of which, it's approaching the flood zones from Florida's experience with Debby, and has isolated 3 and 4 inch per hour rainfall rates... Member Since: January 25, 2012 Posts: 27 Comments: 875

1088. Skyepony (Mod) 2:36 AM GMT on July 02, 2012
Three killed already in that NC storm. Member Since: August 10, 2005 Posts: 144 Comments: 29236

1089. TropicalAnalystwx13 2:37 AM GMT on July 02, 2012
Quoting Ameister12: 1.7 trillion dollars in damage? Holy @!%!* If that storm came to fruition, it would probably be higher than that. Member Since: July 6, 2010 Posts: 89 Comments: 25128

1090. KoritheMan 2:38 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: If that storm came to fruition, it would probably be higher than that. WAY higher. Member Since: March 7, 2007 Posts: 408 Comments: 15417

1091. RTSplayer 2:39 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Doom. Semi-realistic scenario circa 2100 after a few degrees worth of AGW... Member Since: January 25, 2012 Posts: 27 Comments: 875

1092. Ameister12 2:41 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: If that storm came to fruition, it would probably be higher than that. Oh! Yeah it would! O_O Member Since: August 9, 2009 Posts: 9 Comments: 3421

1093. allancalderini 2:41 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Doom. OMG that would truly be an epic disaster. which name did you put to that storm ? Member Since: October 15, 2011 Posts: 0 Comments: 2017

1094. RTSplayer 2:42 AM GMT on July 02, 2012
Fema would be like, "Sorry folks, move to Alaska...that's where we're going." Member Since: January 25, 2012 Posts: 27 Comments: 875

1095. KoritheMan 2:44 AM GMT on July 02, 2012
Quoting RTSplayer: Fema would be like, "Sorry folks, move to Alaska...that's where we're going." Funny thing is, that would probably actually happen. Member Since: March 7, 2007 Posts: 408 Comments: 15417

1096. TropicalAnalystwx13 2:48 AM GMT on July 02, 2012
Quoting allancalderini: OMG that would truly be an epic disaster. which name did you put to that storm ? Marvin. Member Since: July 6, 2010 Posts: 89 Comments: 25128

1097. tropicfreak 2:48 AM GMT on July 02, 2012
Quoting WxGeekVA: Reminds me of Friday... The mets were saying they thought it would weaken but then it didn't... I wasn't really expecting it to weaken. Typically with storms that come from the west... they start off strong but when they pass over the mountains they significantly weaken but once they pass over the Blue Ridge and into the western Peidmont they being to reintensify and by the time they reach I-95 they may be severe. I was never expecting a weak line. I do not want to deal with another storm... done with it. Member Since: September 2, 2006 Posts: 110 Comments: 6565

1098. WxGeekVA 2:49 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Marvin. Chuck Norris Member Since: September 3, 2011 Posts: 13 Comments: 3311

1099. hahaguy 2:51 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Marvin. Sounds about right. Member Since: August 12, 2007 Posts: 2 Comments: 2838

1100. tropicfreak 2:52 AM GMT on July 02, 2012
Quoting TropicalAnalystwx13: Not sure if this has been posted yet, so I'll post it again. I found it funny. Haha that's Aaron Justus from CBS 6 in Richmond VA. I actually know him personally and he never takes himself too seriously. He does have a sense of humor but a great meteorologist. He did this the last day of working at that station last summer. He now lives in San Diego. I wonder how he held himself together throughout the whole thing. Member Since: September 2, 2006 Posts: 110 Comments: 6565

1101. KoritheMan 2:52 AM GMT on July 02, 2012
Quoting hahaguy: Sounds about right. Evening, Brian. Good to see a familiar face. I hope you are doing well. Member Since: March 7, 2007 Posts: 408 Comments: 15417

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