Major severe thunderstorm outbreak expected; U.S. drought intensifies

By: Dr. Jeff Masters , 2:16 PM GMT on July 26, 2012

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A dangerous outbreak of organized severe thunderstorms with strong, damaging winds is expected this afternoon from Ohio eastwards through Pennsylvania and into New England, says NOAA's Storm Prediction Center (SPC). They have put the region, which includes Columbus, Pittsburgh, Philadelphia, and New York City, in their "Moderate Risk" area for severe weather, just one notch below the highest level of alert. Much of the region is also under advisories for extreme heat, with temperatures in the upper 90s expected. This extreme heat will help energize the thunderstorms by making the atmosphere very unstable. A cold front passing through the region will trigger the severe weather episode beginning around 2 pm EDT this afternoon, near the Indiana/Ohio border. This front already triggered a round of severe thunderstorms early this morning across Michigan, which knocked out power to 16,000 customers. This afternoon, severe thunderstorms may organize into a complex that features a bow-shaped echo. If such a complex brings violent straight-line winds in excess of 58 mph (93 km/hr) over a swath of at least 240 miles (about 400 km), it will be called a derecho (from the Spanish phrase for "straight ahead".) The atmosphere is not as unstable as was the case for the June 29 - 30 Mid-Atlantic and Midwest derecho, however. That storm was one of the most destructive and deadly fast-moving severe thunderstorm complexes in North American history. It killed 22 people, knocked out power to at least 3.7 million customers, and did hundreds of millions in damage.


Figure 1. Severe weather risk for Thursday, July 26, 2012, from NOAA's Storm Prediction Center (SPC).

U.S. drought intensifies
The great U.S. drought of 2012 held constant in size but grew more intense over the past week, said NOAA in their weekly U.S. Drought Monitor report issued Thursday, July 26. The area of the contiguous U.S. covered by drought stayed constant at 64% , but the area covered by severe or greater drought jumped from 42% to 46%. These are truly historic levels of drought, exceeded only during the great Dust Bowl drought of the 1930s and a severe drought in the mid-1950s. The July 2012 drought is second only to the great Dust Bowl drought of July 1934 in terms of the area of the contiguous U.S. covered by moderate or greater drought (if we assume the drought conditions measured in mid-July are representative of the entire month of July, which is a reasonable approximation given the lastest drought forecast.) The five months with the greatest percent area in moderate or greater drought, since 1895, now look like this:

1) Jul 1934, 80%
2) Jul 2012, 64%
3) Dec 1939, 60%
4) Jul 1954, 60%
5) Dec 1956, 58%

If we consider the area of the contiguous U.S. covered by severe or greater drought, drought conditions as of July 24, 2012 now rank in 3rd place:

1) Jul 1934, 63%
2) Sep 1954, 50%
3) Jul 2012, 46%
4) Dec 1956, 43%
5) Aug 1936, 43%


Figure 2. July 24, 2012 drought conditions showed historic levels of drought across the U.S., with 64% of the contiguous U.S. experiencing moderate or greater drought, and 46% of the county experiencing severe or greater drought. Image credit: U.S. Drought Monitor.

Extreme heat continues in the Heartland
St. Louis, Missouri's summer of extreme heat reached record levels on Wednesday, when the city hit 108°F. This marked the 11th day this summer in St. Louis with temperatures of at least 105°F, beating the old record of ten such days in 1934. The minimum temperature in the city fell to just 86°F, tying with July 24, 1901, as the warmest minimum temperature ever recorded in the city. St. Louis has seen just 0.53" inches of rain this month, far below the normal 3.35" it usually records by this point in July.

Jeff Masters

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1549. CaribBoy
3:30 PM GMT on July 27, 2012
Quoting StormTracker2K:




What's the h............ :(
Member Since: October 6, 2007 Posts: 0 Comments: 6429
1548. hydrus
3:12 PM GMT on July 27, 2012
Quoting kwgirl:
Well, I hope it stays away from the Keys or at least hits before my windstorm policy renews. Citizens sent me a letter saying they are decreasing my contents insurance to equal 25% of the house coverage. If I want more coverage to contact my agent. A round about way of increasing my rate and decreasing their exposure. Of course, I have not seen the premium yet, but I am sure it will not go down. They know I live in a mobile home, so they deem their risk very high. I guess if a windstorm happens, I better set fire to it before I call the insurance adjuster. Then maybe I will get something out of the loss:(
Insurance companies realize there situation with all the natural disasters that have occurred. People realize what insurance companies will do when things are bad. Be sure to sign and fill everything out correctly. They will take advantage of any situation that will profit the company.
Member Since: September 27, 2007 Posts: 1 Comments: 21766
1547. kwgirl
2:53 PM GMT on July 27, 2012
Quoting hydrus:
I will go out on a branch and say Florida gets a hurricane this year...Hopefully a weak one.This pattern in general has Florida written all over it.
Well, I hope it stays away from the Keys or at least hits before my windstorm policy renews. Citizens sent me a letter saying they are decreasing my contents insurance to equal 25% of the house coverage. If I want more coverage to contact my agent. A round about way of increasing my rate and decreasing their exposure. Of course, I have not seen the premium yet, but I am sure it will not go down. They know I live in a mobile home, so they deem their risk very high. I guess if a windstorm happens, I better set fire to it before I call the insurance adjuster. Then maybe I will get something out of the loss:(
Member Since: March 28, 2008 Posts: 0 Comments: 1532
1546. HurricaneHunterJoe
2:50 PM GMT on July 27, 2012
Quoting Grothar:


Look next to your teeth. LOL


That where you find yours eh?
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1545. HurricaneHunterJoe
2:49 PM GMT on July 27, 2012
BTW Good Morning Gro :)
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1544. LargoFl
2:48 PM GMT on July 27, 2012
FLOOD WARNING
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
849 AM CDT FRI JUL 27 2012

...THE NATIONAL WEATHER SERVICE IN MIDLAND HAS ISSUED A FLOOD WARNING
FOR THE FOLLOWING RIVERS IN TEXAS...

RIO GRANDE AT CANDELARIA 3N AFFECTING PRESIDIO COUNTY

RECENT HEAVY RAINFALL JUST UPSTREAM OF CANDELARIA HAS RESULTED IN
RISES ON THE RIO GRANDE. AS A RESULT...THE RIVER AT CANDELARIA IS
EXPECTED TO RISE TO JUST ABOVE FLOOD STAGE BY THIS AFTERNOON.

IF THIS FLOODING PERSISTS...OR MORE RAINFALL OCCURS UPSTREAM OF
CANDELARIA...ADDITIONAL FLOOD STATEMENTS MAY BE ISSUED LATER TODAY.

RIVER LEVELS ARE HIGH. RANCHERS AND FARMERS SHOULD MOVE LIVESTOCK
AND MACHINERY AWAY FROM FLOOD PRONE AREAS IF TIME PERMITS.

MOTORISTS ARE URGED TO USE CAUTION THROUGH THIS AREA. IF YOU
ENCOUNTER A FLOODED STRETCH OF ROADWAY... DO NOT ATTEMPT TO CROSS IT.
YOUR VEHICLE COULD BE SWEPT DOWNSTREAM IN RUSHING FLOODWATERS.

FOR ADDITIONAL INFORMATION...PLEASE GO TO OUR LOCAL WEBPAGE LOCATED
AT... WWW.WEATHER.GOV/MIDLAND ...SELECT RIVERS AND LAKES AHPS UNDER
CURRENT CONDITIONS.
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1543. WunderAlertBot (Admin)
2:48 PM GMT on July 27, 2012
JeffMasters has created a new entry.
1542. HurricaneHunterJoe
2:48 PM GMT on July 27, 2012
Quoting washingtonian115:
Expect to see nothing on the Atlantic side until the end of August.


By nothing, you mean? No TD? TS? Hurricane? Major Hurricane?
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1541. MAweatherboy1
2:46 PM GMT on July 27, 2012
Quoting TropicalAnalystwx13:

The NHC initiated it this time, and the numbering is correct. The next test invest would be 87E, and this is 91E.

Also it's up on the Navy site:



I could see that having 50kt winds and a 996mb pressure.
Member Since: February 11, 2012 Posts: 84 Comments: 7948
1540. Grothar
2:45 PM GMT on July 27, 2012
Quoting HurricaneHunterJoe:
Im an old man and it is only 730am and I did go to bed at 2am........ I can't find my glasses to find my Ensure!


Look next to your teeth. LOL
Member Since: July 17, 2009 Posts: 71 Comments: 26895
1539. LargoFl
2:45 PM GMT on July 27, 2012
.......................................some of the dry area's of Texas finally getting the rains..there are flash flood warnings til noon there in those area's
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1537. Tropicsweatherpr
2:44 PM GMT on July 27, 2012
Quoting washingtonian115:
Expect to see nothing on the Atlantic side until the end of August.


But you didn't elaborate more on why it will occur that way.
Member Since: April 29, 2009 Posts: 75 Comments: 14571
1536. TropicalAnalystwx13
2:44 PM GMT on July 27, 2012
Quoting Tropicsweatherpr:


Maybe another test invest as there is nothing at that position.

The NHC initiated it this time, and the numbering is correct. The next test invest would be 87E, and this is 91E.
Member Since: July 6, 2010 Posts: 113 Comments: 32529
1535. yoboi
2:44 PM GMT on July 27, 2012
i noticed something on this blog yesterday eve, nobody could agree on what to call a line of storms...how do you really expect people to agree with gw????
Member Since: August 25, 2010 Posts: 7 Comments: 2408
1534. CosmicEvents
2:43 PM GMT on July 27, 2012
Quoting StormTracker2K:


I saw the Tower Cam shot NEA it rained literally 5 minutes real hard then it was over.
The whole event was a normal moderate to severe thunderstorm typical of summer, with the type of spotty widespread damage we see all the time.
Member Since: August 3, 2005 Posts: 10 Comments: 5648
1533. washingtonian115
2:43 PM GMT on July 27, 2012
Expect to see nothing on the Atlantic side until the end of August.
Member Since: August 14, 2010 Posts: 10 Comments: 17486
1532. Tropicsweatherpr
2:41 PM GMT on July 27, 2012
Quoting MAweatherboy1:
What is this?

EP, 91, 2012072712, , BEST, 0, 150N, 1150W, 50, 996, DB


Maybe another test invest as there is nothing at that position.
Member Since: April 29, 2009 Posts: 75 Comments: 14571
1531. yoboi
2:40 PM GMT on July 27, 2012
Quoting Pocamocca:

Vanity over environmentalism.


why not just pour paint down the sewer drain would be the same.
Member Since: August 25, 2010 Posts: 7 Comments: 2408
1530. HurricaneHunterJoe
2:39 PM GMT on July 27, 2012
I actually saw a puff of convection near the circulation on our leading Tropical Wave.

Link
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1529. MAweatherboy1
2:39 PM GMT on July 27, 2012
What is this?

EP, 91, 2012072712, , BEST, 0, 150N, 1150W, 50, 996, DB
Member Since: February 11, 2012 Posts: 84 Comments: 7948
1527. Skyepony (Mod)
2:37 PM GMT on July 27, 2012
Drought reactions..People are paying get their lawn painted with a green latex paint.
Member Since: August 10, 2005 Posts: 193 Comments: 38689
1526. weathermanwannabe
2:36 PM GMT on July 27, 2012
1490. Grothar 9:56 AM EDT on July 27, 2012

I can appreciate that; I was not a mariner but had nice shortwave radio receiver with marine bands and antenna in the backyard when I was a kid (Father got it for me for Christmas when I was 12-13) and used to listen to you folks talking in the 70's as well as BBC world service, Voice of America and Radio Moscow as I got older as I got into politics (my dad was a CIA operative in the 60's).
Member Since: August 8, 2006 Posts: 0 Comments: 9330
1525. LargoFl
2:35 PM GMT on July 27, 2012
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1524. TropicalAnalystwx13
2:35 PM GMT on July 27, 2012
USA! USA! USA!
Member Since: July 6, 2010 Posts: 113 Comments: 32529
1523. stormchaser19
2:35 PM GMT on July 27, 2012
After nearly a three-year absence, forecasters are predicting El Nio will develop over the next few months, which could portend a quiet end to the hurricane season.
"We're not officially there yet," AccuWeather senior meteorologist Brett Anderson says, "but we are trending toward an El Nio."
An El Nio climate pattern is a periodic warming of tropical Pacific Ocean water that affects weather around the world.
The likely development of a full-fledged El Nio episode means that Atlantic hurricane activity will probably be suppressed in 2012, according to Weather Underground meteorologist Jeff Masters. That's because of the strong upper-level winds and high wind shear these events typically bring to the tropical Atlantic.
Wind shear tends to tear apart hurricanes before they develop.
Anderson says that El Nio will most likely form by September, which is the heart of the Atlantic hurricane season.
Depending on how quickly it develops, AccuWeather reports there could be a quick shutdown of tropical storm and hurricane activity during the latter part of the Atlantic season in September and October.
However, there could still be storms in August and early September, before the full effects of El Nio come into play.
Right now, after a quick start to the hurricane season with four named storms in May and June, July has been remarkably quiet in the Atlantic, with no named storms. This would be the first July since 2009 with no named storms, Masters says.
The lack of named storms in July is not related to El Nio but rather is due to disrupting dry air and wind shear -- along with cool waters -- over the tropical Atlantic, according to
AccuWeather tropical weather expert Dan Kottlowski.
Overall, other than a quiet hurricane season, the greatest weather impacts in the USA from El Nio tend to occur in winter, says Michelle L'Heureux, a meteorologist with the Climate Prediction Center.
Usually, L'Heureux says, El Nio produces wetter and cooler-than-average weather across the southern tier of the USA and warmer and drier-than-average conditions across the northern half of the country, which is not good news for the parched upper Midwest.

And for me the only way to see some storm is that EL NINO don't develops until late october


by the way a good sign is the SAL is little weaker
Member Since: June 20, 2012 Posts: 0 Comments: 2169
1522. Tropicsweatherpr
2:31 PM GMT on July 27, 2012
Quoting Grothar:
Not all that much dry air for the waves in the Atl.
With the Atlantic high moving a little to the East, a system getting close to the coast of the US could possibly recurve. Even though this is only 36 hours.







Although the first wave is getting better presentation on the TC formation forecast.



Hi Grothar. I still like the wave that will emerge on Sunday,but that one just offshore looks good.
Member Since: April 29, 2009 Posts: 75 Comments: 14571
1521. HurricaneHunterJoe
2:31 PM GMT on July 27, 2012
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1520. HurricaneHunterJoe
2:30 PM GMT on July 27, 2012
Quoting Grothar:


You finally woke up?
Im an old man and it is only 730am and I did go to bed at 2am........ I can't find my glasses to find my Ensure!
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1518. LargoFl
2:26 PM GMT on July 27, 2012
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1517. HurricaneHunterJoe
2:25 PM GMT on July 27, 2012
Are our Atlantic Tropical Waves healthy today? I see the Pacific seems to be staying somewhat busy?
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1516. Grothar
2:25 PM GMT on July 27, 2012
Quoting HurricaneHunterJoe:
Good Morning To All From America's Left Coast!


You finally woke up?
Member Since: July 17, 2009 Posts: 71 Comments: 26895
1515. LargoFl
2:23 PM GMT on July 27, 2012
.........................................who is the Blobologist here..blob is still there now for days..is this going to organize at some point?
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1514. MAweatherboy1
2:23 PM GMT on July 27, 2012
Yikes. Caribbean shear has spiked big time:



And instability has plummeted:

Member Since: February 11, 2012 Posts: 84 Comments: 7948
1513. poknsnok
2:22 PM GMT on July 27, 2012
Based on what facts?? heads or tails??

Quoting hydrus:
I will go out on a branch and say Florida gets a hurricane this year...Hopefully a weak one.This pattern in general has Florida written all over it.
Member Since: August 17, 2008 Posts: 0 Comments: 222
1512. Grothar
2:21 PM GMT on July 27, 2012
Quoting hydrus:
I will go out on a branch and say Florida gets a hurricane this year...Hopefully a weak one.This pattern in general has Florida written all over it.


I think that's "limb". I'm just in a mischievous mood today, hydrus!
Member Since: July 17, 2009 Posts: 71 Comments: 26895
1511. LargoFl
2:20 PM GMT on July 27, 2012
starting to rain here now, light showers so far coming in off the gulf..typical..there goes that 0% chance of rain LOL
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1510. Grothar
2:19 PM GMT on July 27, 2012
Not all that much dry air for the waves in the Atl.
With the Atlantic high moving a little to the East, a system getting close to the coast of the US could possibly recurve. Even though this is only 36 hours.







Although the first wave is getting better presentation on the TC formation forecast.

Member Since: July 17, 2009 Posts: 71 Comments: 26895
1509. HurricaneHunterJoe
2:19 PM GMT on July 27, 2012
Good Morning To All From America's Left Coast!
Member Since: September 18, 2010 Posts: 0 Comments: 5237
1508. hydrus
2:15 PM GMT on July 27, 2012
Quoting Pocamocca:

Hopefully none at all.
The state is overdue. Its not that I want one to hit there. We lost just about everything to Charley and Jeanne.
Member Since: September 27, 2007 Posts: 1 Comments: 21766
1507. Skyepony (Mod)
2:13 PM GMT on July 27, 2012
ASCAT just missed the Central Atlantic wave. Here's OSCAT from lastnight.
Member Since: August 10, 2005 Posts: 193 Comments: 38689
1505. MAweatherboy1
2:12 PM GMT on July 27, 2012
The TCFA I posted was for 93W, but IMO 95W looks even better:



27/0832 UTC 24.6N 148.4E T1.5/1.5 95W -- West Pacific
Member Since: February 11, 2012 Posts: 84 Comments: 7948
1504. Skyepony (Mod)
2:11 PM GMT on July 27, 2012
Couple of hundred thousand without power after the storms yesterday. Atleast two died.. The one, what a way to go. Lightning struck a church causing a scaffold to fall on him. Details..

More storms expected today. Stay safe up there.
Member Since: August 10, 2005 Posts: 193 Comments: 38689
1503. LargoFl
2:10 PM GMT on July 27, 2012
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1502. MAweatherboy1
2:10 PM GMT on July 27, 2012
WTPN21 PGTW 271400
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 11.8N 128.4E TO 16.4N 124.1E
WITHIN THE NEXT 06 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN
THE AREA ARE ESTIMATED TO BE 18 TO 23 KNOTS. METSAT IMAGERY AT
271300Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.7N
127.6E. THE SYSTEM IS MOVING WESTWARD AT 08 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.4N 129.2E, IS
NOW LOCATED NEAR 12.7N 127.6E, APPROXIMATELY 395 NM EAST-SOUTHEAST OF
MANILA, PHILIPPINES. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
SHOWS A VERY BROAD SYSTEM WITH FRAGMENTED FEEDER BANDS THAT HAS
FURTHER CONSOLIDATED OVER THE PAST 12 HOURS. THIS IS SUPPORTED BY A
271144Z SSMI-S MICROWAVE IMAGE THAT CLEARLY OUTLINES THE CONVECTIVE
BANDING AND THE LOW LEVEL CIRCULATION CENTER. UPPER LEVEL ANALYSIS
INDICATES THE VERTICAL WIND SHEAR HAS WEAKENED AS THE STORM MOTION
BECAME IN-PHASE WITH THE UPPER LEVEL WINDS. THE CYCLONE IS BEING
STEERED WESTWARD BY A LOW- TO MID-LAYERED SUBTROPICAL RIDGE TO THE
NORTH. IN ADDITION TO THE IMPROVED UPPER LEVEL CONDITIONS, THE SEA
SURFACE TEMPERATURES IN THE AREA ARE PERENNIALLY FAVORABLE FOR
CYCLOGENESIS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO
23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB.
DUE TO THE IMPROVED BANDING AND SHEAR ENVIRONMENT, THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
281400Z. //
NNNN



Member Since: February 11, 2012 Posts: 84 Comments: 7948
1501. icmoore
2:10 PM GMT on July 27, 2012
Quoting reedzone:


Wrong, this is the type of pattern similar to Frances in 2004. Strong ridge in the Atlantic, weak trough off the East Coast, not strong enough for a recurvature out to sea. This would bring a storm into the Southeast.


Please don't say the "f" word, Frances :)I lived in the interior NE FL at the time and we still lost our lights for a week.
Member Since: July 18, 2005 Posts: 9 Comments: 4146
1500. hydrus
2:09 PM GMT on July 27, 2012
I will go out on a branch and say Florida gets a hurricane this year...Hopefully a weak one.This pattern in general has Florida written all over it.
Member Since: September 27, 2007 Posts: 1 Comments: 21766
1499. LargoFl
2:09 PM GMT on July 27, 2012
Member Since: August 6, 2011 Posts: 4 Comments: 41000

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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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