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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705. wpb
Quoting nigel20:

Yeah, it's one of four radars that were constructed in the Caribbean from the European Development Fund
Link
is there a website that has the real time radar displays for these new sites?
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Ascat showing a low with the large tropical wave near 33w
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Quoting Tropicsweatherpr:


Yeah,that is bad. I was hoping that all the islands would get rain from this wave,but I guess the strong ridge pushed the majority of the weather to the south. Our friend pottery in TT will get rain very soon.

Yeah, it has been pretty wet in the southern windward islands, so they are not the ones that need the rain.
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702. MZT
I'll admit, I hope it doesn't get quite as hot as yesterday. I'm trying to save some $ this summer, have left my A/C off. Yesterday, the walls and furniture felt warm. Turn on the tap, and the first slug of water felt warm.

It would be hard to imagine living in an environment where it gets to 105 every day in the era before refrigeration. No wonder the siesta was invested first.
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Quoting Tribucanes:
Be back later have a great day all. And I've heard it a thousand times here for the obvious trolls, just report and ignore. They often post pictures and the whatnot to slow the blog down and cause issues. Best not to even click on em and see what they're saying. Almost always not worth it in the first place.

EXACTLY!!! 

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Quoting GeorgiaStormz:


look at the typical hole around and N of atlanta.
We never get the good stuff.



BTW what can you access on GREarth, is it basically everything?
Can you get all the products the SPC Mesoscale analysis uses?
I know you can zoom.
And how often does it update the current temps?
Does it access models?
And where does it get its info from, the NWS?

Just wondering because i am conidering buying it

For Mesoscale analysis, it can't display everything, but it has a good chunk of it. The current temperatures update every 30 minutes.

Models it uses:

* GFS
* NAM12
* NAM4
* HRW
* RAP
* HRRR

Data on dewpoint, temperature, etc comes from the NWS. Hurricane forecasts come from the NHC (obviously), and Severe Weather forecasts come from the SPC (obviously).
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Quoting wpb:
new radar at barbados???

Yeah, it's one of four radars that were constructed in the Caribbean from the European Development Fund
Link
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This may be the beginnings of something in the Chicago area.

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MONTHLY TROPICAL WEATHER SUMMARY
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN JUL 1 2012

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

TWO TROPICAL STORMS FORMED IN THE BASIN DURING MAY. WHILE IT IS NOT
UNUSUAL TO HAVE TROPICAL CYCLONES FORM BEFORE THE OFFICIAL START OF
THE HURRICANE SEASON...THERE ARE ONLY TWO OTHER YEARS...1887 AND
1908...WHEN TWO TROPICAL CYCLONES OCCURRED BEFORE 1 JUNE. TROPICAL
STORM BERYL MADE LANDFALL NEAR JACKSONVILLE BEACH FLORIDA EARLY ON
28 MAY...MAKING IT THE STRONGEST PRE-JUNE TROPICAL CYCLONE EVER TO
IMPACT THE UNITED STATES COASTLINE.

TWO TROPICAL CYCLONES FORMED IN THE BASIN DURING JUNE...HURRICANE
CHRIS AND TROPICAL STORM DEBBY. BASED ON A 30-YEAR AVERAGE FROM
1981 TO 2010...A NAMED STORM FORMS IN THE BASIN IN JUNE ABOUT ONCE
EVERY OTHER YEAR...WHILE A HURRICANE FORMS IN THE BASIN IN JUNE
ONLY ABOUT ONCE EVERY SEVEN OR EIGHT YEARS. ALSO...THE FORMATION OF
DEBBY ON 23 JUNE MARKED THE EARLIEST FORMATION OF FOUR NAMED STORMS
ON RECORD IN THE BASIN.

IN TERMS OF ACCUMULATED CYCLONE ENERGY...WHICH MEASURES THE COMBINED
STRENGTH AND DURATION OF TROPICAL STORMS AND HURRICANES...TROPICAL
CYCLONE ACTIVITY IN THE BASIN SO FAR THIS YEAR IS WELL ABOVE THE
1981-2010 AVERAGE...AND IS THE HIGHEST VALUE FOR ANY YEAR SINCE
1968.

REPORTS ON INDIVIDUAL CYCLONES...WHEN COMPLETED...ARE AT THE WEB
SITE OF THE NATIONAL HURRICANE CENTER...USE LOWER-CASE LETTERS...
HTTP://WWW.HURRICANES.GOV/2012ATLAN.SHTML

SUMMARY TABLE

NAME DATES MAX WIND (MPH)
------------------------------------------------- --
TS ALBERTO 19-22 MAY 60
TS BERYL 26-30 MAY 70
H CHRIS 19-22 JUN 75
TS DEBBY 23-27 JUN 60
------------------------------------------------- --


$$
HURRICANE SPECIALIST UNIT
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696. wpb
Quoting nigel20:
Most of the precipitation from the tropical wave is missing the islands...not good for the islands that are experiencing drought conditions.

new radar at barbados???
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Quoting MAweatherboy1:

I don't know for sure... It looks that way on the model but it's way north so it may not be.


12z GFS had anything of importance going to July 17th. Yes,some waves moving thru the MDR but nothing of significance. Only at the 17th,it had something in the SW Caribbean.
Member Since: April 29, 2009 Posts: 75 Comments: 14210
SYNOPSIS FOR CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO
19N BETWEEN 55W AND 64W
1034 AM EDT SUN JUL 1 2012

.SYNOPSIS...A TROPICAL WAVE ALONG 64W IS MOVING W AT 17 KT. THE WAVE
WILL APPROACH 68W TONIGHT...NEAR 71W MON MORNING MORNING...NEAR
75W MON NIGHT...THEN MOVE ACROSS THE WESTERN CARIBBEAN TUE
THROUGH WED. THE WAVE WILL BE ACCOMPANIED BY SCATTERED SHOWERS
AND TSTMS WITH GUSTY WINDS. A SECOND LARGE TROPICAL WAVE IN THE
FAR EASTERN TROPICAL ATLC IS EXPECTED TO REACH THE TROPICAL ATLC
WATERS TUE AFTERNOON...ACCOMPANIED BY INCREASING WINDS AND SEAS.
HIGH PRES FROM THE CENTRAL ATLC TO THE SW ATLC WILL SHIFT N THROUGH
THE PERIOD.

SYNOPSIS FOR THE SW N ATLANTIC INCLUDING THE BAHAMAS
1034 AM EDT SUN JUL 1 2012

.SYNOPSIS...A RIDGE FROM 27N65W SW TO THE STRAITS OF FLORIDA WILL
SHIFT N TO 27N MON...AND TO 28N THROUGH THU. A DISSIPATING
TROUGH FROM 25N79W SW TO ACROSS THE SE BAHAMAS WILL MOVE ACROSS
THE REMAINDER OF THE SE BAHAMAS THROUGH TONIGHT...AND ACROSS THE
CENTRAL BAHAMAS MON AND MON NIGHT. E WINDS WILL INCREASE ACROSS
MUCH OF THE SOUTHERN WATERS BEGINNING LATE TONIGHT AND THROUGH
THU.

Member Since: October 25, 2005 Posts: 19 Comments: 21883
Quoting TropicalAnalystwx13:
Current MUCAPE:

Ouch..



look at the typical hole around and N of atlanta.
We never get the good stuff.



BTW what can you access on GREarth, is it basically everything?
Can you get all the products the SPC Mesoscale analysis uses?
I know you can zoom.
And how often does it update the current temps?
Does it access models?
And where does it get its info from, the NWS?

Just wondering because i am conidering buying it
Member Since: February 11, 2012 Posts: 0 Comments: 9725
Member Since: February 11, 2012 Posts: 0 Comments: 9725
Quoting nigel20:
Most of the precipitation is missing the islands...not good for the islands that are experiencing drought conditions.



Yeah,that is bad. I was hoping that all the islands would get rain from this wave,but I guess the strong ridge pushed the majority of the weather to the south. Our friend pottery in TT will get rain very soon.
Member Since: April 29, 2009 Posts: 75 Comments: 14210
Quoting GeorgiaStormz:


fully tropical?

I don't know for sure... It looks that way on the model but it's way north so it may not be.
Member Since: February 11, 2012 Posts: 83 Comments: 7733
Looks like i might get to go to DC on 3 consecutive weekends while my brother is at a weather camp.
I cant wait to see the smithsonians again.

And that derecho doesnt look good again, wonder if theyll upgrade to an MDT
Member Since: February 11, 2012 Posts: 0 Comments: 9725
Most of the precipitation from the tropical wave is missing the islands...not good for the islands that are experiencing drought conditions.

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Quoting MAweatherboy1:
12z GFS 156 hours... That storm is way up north but looks fully tropical...



fully tropical?
Member Since: February 11, 2012 Posts: 0 Comments: 9725
Afternoon, all. Looks like more severe weather coming for parts of the NE and Central US?
Member Since: October 25, 2005 Posts: 19 Comments: 21883
SPC 11:30am update..

...SRN VA/NC THIS AFTERNOON/EVENING...
A SMALL MCS OVER SW VA HAS PRODUCED DAMAGING WINDS AND ISOLATED
LARGE HAIL DURING THE PAST COUPLE OF HOURS. GIVEN THE STRONG
SURFACE HEATING DOWNSTREAM ACROSS VA/NC...MODIFIED 12Z SOUNDINGS
SUGGEST THAT SOME UPSCALE GROWTH AND MORE EXTENSIVE SURFACE-BASED
STORM DEVELOPMENT IS POSSIBLE THIS AFTERNOON. MIDLEVEL LAPSE RATES
ARE UNUSUALLY STEEP OVER THIS AREA...WHICH WILL SUPPORT
STRONG-EXTREME INSTABILITY THIS AFTERNOON AS SURFACE TEMPERATURES
WARM TO NEAR 100 F...ESPECIALLY ALONG AND E OF A WEAK SURFACE TROUGH
ACROSS THE CENTRAL CAROLINAS. GIVEN THE THERMODYNAMIC
ENVIRONMENT...AS WELL AS THE SRN FRINGE OF 30-40 KT MIDLEVEL WNWLY
FLOW...THERE WILL BE THE POTENTIAL FOR AN ORGANIZED DAMAGING WIND
CORRIDOR ACROSS SRN VA AND NC THIS AFTERNOON WITH THE ONGOING MCS.
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Current MUCAPE:

Ouch..

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New SPC outlook...

Member Since: February 11, 2012 Posts: 83 Comments: 7733
Good morning everyone!

Daily SOI: 5.5
30 Day SOI: -10.3
90 Day SOI: -5.8

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We have another super derecho setting up across almost the exact same area that got hit the other day.
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there thats a end of that
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
.
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
O'Hare airport must be a disaster right now... Nasty line of severe storms moving in there.
Member Since: February 11, 2012 Posts: 83 Comments: 7733
Quoting Tribucanes:
Taz please take your hand back from the fence and quit feeding the hungry troll. It's best to keep them completely ignored so they can wallow in what they do best, be miserable. An ignored Troll is a caged Troll. Don't feed them!



am this about ready too poof that troll not wasting my time
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
Taz please take your hand back from the fence and quit feeding the hungry troll. It's best to keep them completely ignored so they can wallow in what they do best, be miserable. An ignored Troll is a caged Troll. Don't feed them!
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Quoting aislinnpaps:
Taz,
Meet 'Maria' as Earnesto2012 told us was his/her real name last night. Notice the join date and the posts made. Says it all...



am starting too wounder if this guy is JFV or this other troll that likes haveing death and doom too evere one
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
12z GFS 156 hours... That storm is way up north but looks fully tropical...

Member Since: February 11, 2012 Posts: 83 Comments: 7733
Be back later have a great day all. And I've heard it a thousand times here for the obvious trolls, just report and ignore. They often post pictures and the whatnot to slow the blog down and cause issues. Best not to even click on em and see what they're saying. Almost always not worth it in the first place.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Quoting ernesto2012:
taz you are just full of good news ...think of something positive like a cat 4 is knocking on your door...




how in the heck is that positive? do you like have deaths and haveing people liveing homeless after there house is heavy damage or gone? whats worng with you i dont want a cat 4 knocking on my door or do i think any one in FL would or any one on the gulf coast would



i dont mine haveing a cat 4 has long has they are tracking safey out too sea with out hurting any one
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
MESOSCALE DISCUSSION 1332
NWS STORM PREDICTION CENTER NORMAN OK
1111 AM CDT SUN JUL 01 2012

AREAS AFFECTED...THE NORTHEAST/UPPER MID-ATLANTIC

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY

VALID 011611Z - 011715Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SCATTERED TSTMS SHOULD FORM THIS AFTERNOON WITH ATTENDANT
THREATS FOR SEVERE HAIL AND DAMAGING WIND. AREA WILL BE UPGRADED TO
SLIGHT RISK WITH THE 1630Z D1 OUTLOOK AND WATCH ISSUANCE WILL BE
CONSIDERED IN THE NEXT COUPLE OF HOURS.

DISCUSSION...CU HAS INITIATED ALONG THE HIGHER TERRAIN OF SRN NY
INTO CNTRL PA ALONG A WEAK LOW-LEVEL BAROCLINIC ZONE BENEATH THE
INFLUENCE OF SUBTLE UPPER-LEVEL IMPULSES CROSSING THE LOWER GREAT
LAKES. 12Z OPERATIONAL GUIDANCE ALONG WITH RECENT HRRR RUNS HAVE A
PRONOUNCED SIGNAL FOR CONVECTIVE DEVELOPMENT...LEADING TO INCREASING
CONFIDENCE THAT POTENTIALLY SCATTERED TSTMS SHOULD FORM CENTERED
TOWARDS THE HUDSON VALLEY. SURFACE TEMPERATURES HAVE WARMED INTO THE
UPPER 80S AND LOWER 90S WITH DEW POINTS HOLDING IN THE MIDDLE TO
UPPER 60S...WHICH IS YIELDING MODERATE BUOYANCY /INCREASING WITH SRN
EXTENT/ PER MODIFIED 12Z IAD/OKX RAOBS. MODERATELY STRONG NEARLY
UNIDIRECTIONAL WLY FLOW WILL BE SUFFICIENT FOR ORGANIZING UPDRAFTS
WITH THREATS OF SEVERE HAIL AND DAMAGING WIND.

..GRAMS/THOMPSON.. 07/01/2012
Member Since: February 11, 2012 Posts: 83 Comments: 7733
Taz,
Meet 'Maria' as Earnesto2012 told us was his/her real name last night. Notice the join date and the posts made. Says it all...
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I feel pretty lucky... Only 84 degrees here :)
Member Since: February 11, 2012 Posts: 83 Comments: 7733
667. Tygor
Quoting flsky:

So where is this?


Sorry, just outside of San Antonio
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RTS your right, December 21st won't be the end; I couldn't agree with you more there. Doesn't mean something really unpredictably bad won't happen, whether it be financial collapse, mega natural disaster, or God forbid, another war that escalates this time. I'm not saying it will or it won't. I'm just saying when we get to that date with none of those things happening, I'll feel much better. If any of the before mentioned happens, I fear it could signal the beginning of the Tribulation. That's just my personal belief.
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Quoting GeorgiaStormz:
temp went from 88 to 97 in 1 hr at the county airport near my house

DP 66F
RH 36%
DI 101

Currently now 99F at my house
and i have to go mow the lawn

Mow it later.
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temp went from 88 to 97 in 1 hr at the county airport near my house

DP 66F
RH 36%
HI 101

Currently now 99F at my house
and i have to go mow the lawn
Member Since: February 11, 2012 Posts: 0 Comments: 9725
Quoting Tazmanian:
if EL nino really gets going in in mid too late july AUG and SEP could be dead has far for name storms gos



but i can say the same for the E PAC

Waters in the east Pacific have already [unofficially] reached the 0.5 °C threshold. This will be seen in the CPC update.

Most of our activity will come in August/September. It will be far from dead, considering things should shut off quickly after September.
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Quoting ernesto2012:
well at least we will have some excitement with the sun....we need a cat 4 in the caribbean..



we do not need a cat 4 in the caribbean




that would be vary bad
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
if EL nino really gets going in in mid too late july AUG and SEP could be dead has far for name storms gos



but i can say the same for the E PAC
Member Since: May 21, 2006 Posts: 5091 Comments: 114919
Just natural cooling feature on the Sun, very cool and imposing looking but not DOOM!
Member Since: April 18, 2012 Posts: 0 Comments: 2437
Quoting Tropicsweatherpr:


Yes,I know. There is no TC around the world now,imagine that.There are two wimpy invests in WPAC.


Strangely quiet.
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I'm not sure I like Coronal Holes
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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.