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

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

Share this Blog
43
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

Sign In or Register Sign In or Register

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: 1399 - 1349

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 | 25 | 26 | 27 | 28 | 29 | 30 | 31Blog Index

Looking at all those radars it really shows how hurricanes moving north after the gulf coast, while destructive near the shore, are so beneficial to inland areas as it brings a deluge of long soaking rains to almost the entire area north and east of where it makes landfall.
Member Since: Posts: Comments:
Quoting Civicane49:


good to see Georgia getting some rain.
Member Since: September 18, 2010 Posts: 0 Comments: 5296
Member Since: Posts: Comments:
Night/morning everyone
See you all later.
Member Since: Posts: Comments:
Something tells me we are headed for dangerous times. It has been too long without a storm, and luck doesn't last forever.
Member Since: Posts: Comments:
Dolly:

Omar:
Member Since: Posts: Comments:
Gustav:

Wilma:

Jeanne:

Frances:
Member Since: Posts: Comments:
Couldn't find a local radar for Ivan. He hit almost exactly where Rita did but a year earlier and thankfully a lot weaker here.
Member Since: Posts: Comments:
1391. TXCWC
18Z and 0z GFS (12Z showed a system in the Bay of Campeche) MAY,MAY be sniffing something out in the 11-15 day range:

18Z 324hr



0Z 264hr
Member Since: Posts: Comments:
Irene:

Charley:

Ivan:
Member Since: Posts: Comments:
Ya beat me to Ike so here's an Humberto. :)

Member Since: Posts: Comments:
1388. JLPR2
Well I'm going to bed then.

Good night everyone!
Member Since: Posts: Comments:
Katrina and Ike at landfall:
Member Since: Posts: Comments:
Quoting Civicane49:

I think this latest wave to exit the African coast looks pretty decent. It is a bit further south than the previous one that came off, and that first wave probably moistened the atmoshpere a bit to allow for this one to have a better shot at development.
Member Since: Posts: Comments:
Rita making landfall. 3 hour gap after she knocked out the radar.

Member Since: Posts: Comments:
Don't consider... its CMC

Member Since: Posts: Comments:
1383. JLPR2
My favorite is Earl...



Archive goes back to 05, would have loved to see Georges in this color scheme, ehh, the one in my PC will have to do.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
1381. bappit
Quoting MrBoujangles:

These little streaks on the radar are pretty interesting. They are all aligned in the same direction and appear to be returns from the radars when they switch to another mode or something. You can see that they all happen in the NW part of the radar, are pretty good distance from the station, and are clearly just wedges of return and not like something actually happening in the atmosphere.

Those streaks are the sun. The sun emits energy at the same wave length that the radar is tuned to. As the sun sinks below the horizon, the radar picks up that energy and displays it as a spike in the direction of the setting sun.
Member Since: Posts: Comments:
Aliens....


(in comment 1373)
Member Since: Posts: Comments:
1379. JLPR2
Now I'm searching for radar loops of storms passing though my area...

Here's pre-Fay...

Member Since: Posts: Comments:
I know this is about oh...forever...late. But a couple of interesting things in the discussion. Not the least of which is who or what are the Jasons. lol

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
230 PM EDT THU JUL 26 2012


------------------------------------------------- ----------------
12Z MODEL UPDATE...
THE 12Z MODEL FORECASTS ARE REASONABLY CONSISTENT WITH THEIR
PREVIOUS RUNS. THE GFS FORECAST WAS RELIED ON FOR MUCH OF THE
FORECAST PERIOD THROUGH TUE. ONE EXCEPTION REMAINS THE TROPICAL
WAVE CURRENTLY NEAR 30W AND EXPECTED TO MOVE INTO THE TROPICAL N
ATLC ZONE ON SUN. THE 12Z ECMWF HAS TRENDED SLIGHTLY STRONGER
WITH THE INVERTED TROUGHING ASSOCIATED WITH THIS WAVE...BUT IS
STILL LESS CONSOLIDATED THAN THE 12Z GFS WHICH DEVELOPS A CLOSED
LOW PRES SYSTEM OVER THE WEEKEND BEFORE IT MOVES THROUGH THE
LESSER ANTILLES. THE FAVORED FORECAST IS STILL WEAKER THAN THE
GFS.

CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W...
THE TROPICAL WAVE PASSING THROUGH THE NW CARIBBEAN SHOULD EXIT
THE AREA BY FRI. SHOWERS AND TSTMS ARE PRIMARILY CONFINED TO THE
AREA WITHIN 150 NM N OF HONDURAS NEAR THE WAVE AND ARE BEGINNING
TO MOVE INTO THE GULF OF HONDURAS. TO THE E OF THIS WAVE...HIGH
PRES N OF THE AREA IS MAINTAINING FRESH TO STRONG E-NE WINDS
ACROSS THE BASIN. EXPECT WINDS TO INCREASE TO AROUND 30 KT NEAR
COAST OF COLOMBIA LATER OVERNIGHT TONIGHT THROUGH FRI EVENING
WITH MAX SEAS BUILDING TO 11-14 FT ACROSS THE SOUTH-CENTRAL
CARIBBEAN. THE AREA OF FRESH-STRONG WINDS WILL ALSO EXPAND
WESTWARD REACHING THE COAST OF NICARAGUA BY FRI. THE GFS IS
DOING A REASONABLY GOOD JOB DEPICTING THE TRADE WINDS AND THE
WAVE IN THE NW CARIBBEAN. A SECOND TROPICAL WAVE LIES ALONG 47W.
THIS WAVE WILL CONTINUE WESTWARD THROUGH THE TROPICAL N ATLC FRI
INTO SAT MORNING...THE E CARIBBEAN SAT AFTERNOON THROUGH
SUN...AND INTO THE CENTRAL CARIBBEAN MON. THE WAVE IS EMBEDDED
IN AN AREA OF DRY AIR AND AFRICAN DUST THAT IS INHIBITING
CONVECTION. WINDS ARE ONLY A MODERATE BREEZE WITH THE SYSTEM. A
SIMILAR AIRMASS IS ALSO IMPACTING THE TROPICAL WAVE ALONG 30W.
THE CYCLONIC CIRCULATION ASSOCIATED WITH THIS WAVE IS VERY BROAD
AT THE MOMENT. THE 06Z GFS AND 00Z UKMET SHOW CONSOLIDATION OF
THIS SYSTEM INTO A BETTER DEFINED LOW PRES CENTER AS IT MOVES
INTO THE TROPICAL N ATLC SUN/MON COMPARED TO THE 00Z ECMWF.
THESE THREE MODELS ARE IN REASONABLE AGREEMENT ON THE TIMING OF
THE SYSTEM. GIVEN ITS CURRENT ENVIRONMENT AND STRUCTURE...
CONFIDENCE IS LOW IN CARRYING A SYSTEM AS STRONG AS THE
GFS/UKMET IN THE MEDIUM RANGE. THE GRIDS WERE ADJUSTED TOWARD A
BLEND OF THE GFS AND THE WEAKER ECMWF.

SW N ATLC S OF 31N W OF 65W...
A COLD FRONT LIES FROM 31N62W TO 29N68W AND BECOMES STATIONARY
TO 31N74W. SHIP OBSERVATIONS AND THE 0122 UTC ASCAT AND 0330 UTC
OSCAT PASSES SHOW FRESH S TO SW WINDS STILL LIE N OF 29N E OF
THE BOUNDARY TO 50W. JASON1 AND JASON2 PASSES ALSO CAPTURED SEAS
IN THE 8-9 FT RANGE AHEAD OF THE FRONT. THE FRONT HAS FORCED THE
SUBTROPICAL RIDGE SOUTHWARD FROM ITS USUAL POSITION.
THE RIDGE
AXIS CURRENTLY EXTENDS ACROSS THE REGION FROM 24N65W TO 26N80W
BUT WILL LIFT TO 28N BY MON. MODERATE TO FRESH TRADE WINDS WILL
PERSIST S OF THE RIDGE AS THE NORTH END OF TWO TROPICAL WAVES
MAKE THEIR WAY THROUGH SE WATERS. THE FIRST WAVE IS EXPECTED TO
MOVE THROUGH PUERTO RICO EARLY SUN WHILE THE SECOND WAVE WILL
BEGIN TO APPROACH FAR SE WATERS MON. SEE THE SECTION ABOVE FOR
MORE DETAILS ON THESE ATLC TROPICAL WAVES.
Member Since: Posts: Comments:
Quoting MrBoujangles:

These little streaks on the radar are pretty interesting. They are all aligned in the same direction and appear to be returns from the radars when they switch to another mode or something. You can see that they all happen in the NW part of the radar, are pretty good distance from the station, and are clearly just wedges of return and not like something actually happening in the atmosphere.
Its called a sun echo and here is an explaination:
Radar receivers in the national network of Doppler radars (WSR-88D) can detect sunsets. Here, in a composite of reflectivity images across the east-central U.S., seven sites did so. A radar antenna was located at each location numbered in yellow, with the sun at a low enough angle to the ground to be intercepted head-on by the radar beam.

Since it was winter -- only a few days after solstice -- the sun sets in the southwest in these areas; so the sunset echoes appear as blue line segments southwest of each radar site. The tilt of the earth causes the sun to set later at more southerly latitudes in winter, which is why the sunsets show up farther east as you look from Minnesota to Tennessee. By contrast, in the summer, the sunset echoes would be facing northwest; and they would appear farther west as you go southward. At the start of spring and fall, each sunset echo would face east-west, and the whole series of them would be arranged in a north-south band. In nationwide radar reflectivity loops, the sunset can often be tracked east-west across the country by following the appearance of the sun echoes over several hours.

[The large area of blues and greens over Iowa was a belt of snow. Some radars failed to show sunsets because of precipitation and dense cloud cover obscuring the sun.]

These radars can pick up the sun as an echo because the sun transmits radiation at all wavelengths. This includes the 10-cm long microwaves sent and received by the radars. When the sun is low in the sky, and a radar beam moves across it, the sun's 10-cm microwave emissions are strong enough to register in the radar receiver. Unfiltered, these echoes pass through the computer software processing and show up on radar displays. They are easily distinguished from precipitation echoes by their character: occurring only around sunrise or sunset, shaped straight, nearly uniform in intensity, elongated with the radar beam and facing the direction of the sun.

And a picture:
Member Since: Posts: Comments:
1280 spathy: Waiting for the No politics responses for this... [from] 1276 sunlinepr
More storms may trigger ozone depletion in populated areas far from the Poles
If you think this comment is not politics then you don't know how to get the results that this agenda wants. Not to mention how this mindset has gotten this far.

Could you explain what you just wrote?
What mindset? How far has that mindset gotten?
What agenda? What results does that agenda want?
Why is that excerpt from NationalGeographics political?
What would you consider to be a no-politics response?
Member Since: Posts: Comments:
Next wave please step forward.
Member Since: Posts: Comments:
I know this is 384hrs and it is useless but it shows a strong wave/low coming off Africa.

And as for boredom I have recovered from a broken arm, made my lawn almost perfect, watched every storm chasers episode for season 1-4 multiple times, looked back at some big hurricanes/tornado outbreaks in the 2000s/2010s, and became a storm spotter. Im pretty bored but not at the top of the boredom chart.
Member Since: Posts: Comments:

These little streaks on the radar are pretty interesting. They are all aligned in the same direction and appear to be returns from the radars when they switch to another mode or something. You can see that they all happen in the NW part of the radar, are pretty good distance from the station, and are clearly just wedges of return and not like something actually happening in the atmosphere.
Member Since: Posts: Comments:
1372. vanwx
Quoting Pirate999:


Why thank you kind sir but I should have put quotes around that comment and entire article since I cannot lay claim to that comment..

Regarding papers that counter that, I do not have immediate access but offer the scientist blog here. http://dartmouthigert.wordpress.com/2012/07/21/new -summit-melt-layer/

Unfortunately you seem to believe that I am challenging the idea of melt, but obviously sir you are mistaken. I am challenging NASA's findings based on images and not core samples as well as their statement around unpresidented when a scienctist has determined differenty.


You're way too kind. I'm going to adopt that as my motto; "AGW is just hot air" like 'acid oceans have happened before' or 'We've had dust-bowls before", or "Romans had tax problems too'. 'Galileo should be locked up',"more prison time for Voltaire', 'Columbus is doomed', etc, Thanks Pirate999
Member Since: Posts: Comments:
1371. JLPR2
Quoting KoritheMan:


It's a good time waster, too. Before I knew it, I realized "You know what? I have been doing this for two months."


Yikes! I remember I did that for Hurricane Georges and Hurricane Hugo in 2010 or 09.

And yes, it's an awesome time waster/killer/spender. xD
Member Since: Posts: Comments:
Quoting JLPR2:


Yes it does.
Not bored enough to read all of that.

Though my backyard is beautifully clean and all the plants are trimmed, happy and with lots of attention.

-.-


It's a good time waster, too. Before I knew it, I realized "You know what? I have been doing this for two months."
Member Since: Posts: Comments:
1369. JLPR2
Quoting KoritheMan:


Since the start of the season, I've scoured the NHC advisory archive for each storm (including the Pacific) from 1998 to 2003. Tonight I finished watching (er, reading?) Grace die, and am watching Fabian spread its wings toward Bermuda. I think all of this officially makes me more bored than you.


Yes it does.
Not bored enough to read all of that.

Though my backyard is beautifully clean and all the plants are trimmed, happy and with lots of attention.

-.-
Member Since: Posts: Comments:
Quoting JLPR2:
My God, I'm so bored...

You guys have any idea how many videos of hurricane tracking, loops, chasing I have seen in youtube? XD

Even I lost track.


Since the start of the season, I've scoured the NHC advisory archive for each storm (including the Pacific) from 1998 to 2003. Tonight I finished watching (er, reading?) Grace die, and am watching Fabian spread its wings toward Bermuda. I think all of this officially makes me more bored than you.
Member Since: Posts: Comments:
1367. JLPR2
Quoting TropicalAnalystwx13:

Check the WPAC...two active TD's.


I see two active invests, no TDs.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting wxchaser97:
It will take a couple weeks until anything develops and noting much on the gfs as of now.


according the forecast, in the next two weeks, the environment will become more favorable for tropical storm formation
Member Since: Posts: Comments:
Not much weather news around here for sure. Only thing vaguely tropical I've seen was 12z GFS closed off a low and sent it into Mexico...at the end of the run...wasn't there 18z...probably won't be there this run...lol

Member Since: Posts: Comments:
Quoting JLPR2:


I was hoping for at least an invest, but nothing...

The entire world is currently devoid of tropical systems. *sigh

Check the WPAC...two active TD's.
Member Since: July 6, 2010 Posts: 113 Comments: 33450
Quoting JLPR2:


I was hoping for at least an invest, but nothing...

The entire world is currently devoid of tropical systems. *sigh
It will take a couple weeks until anything develops and noting much on the gfs as of now.
Member Since: Posts: Comments:
KY and WV are getting some heavy training rain right now.
Member Since: Posts: Comments:
1360. vanwx
Quoting MontanaZephyr:
New York Times:

Storms Threaten Ozone Layer Over U.S., Study Says

Link


Thanks for that eye opener MZ, that high energy UV willcertainly not re-radiate into space.
Member Since: Posts: Comments:
1359. JLPR2
Quoting wxchaser97:
It's July, we are all bored.
Not much wx has been going on besides hot and dry except for the occasional severe t-storm but that hasnt given much to talk about.


I was hoping for at least an invest, but nothing...

The entire world is currently devoid of tropical systems. *sigh
Member Since: Posts: Comments:
Quoting JLPR2:
My God, I'm so bored...

You guys have any idea how many videos of hurricane tracking, loops, chasing I have seen in youtube? XD

Even I lost track.
It's July, we are all bored.
Not much wx has been going on besides hot and dry except for the occasional severe t-storm but that hasnt given much to talk about.
Member Since: Posts: Comments:
SAL is being reduced
Member Since: Posts: Comments:
where o where have our tropical cyclones gone? I thought surely we'd have at least one named storm during this month of July, since that is our long-term average for this month anyways. Well, we still have 5 days left in the month so I suppose it can still happen
Member Since: Posts: Comments:
1355. JLPR2
My God, I'm so bored...

You guys have any idea how many videos of hurricane tracking, loops, chasing I have seen in youtube? XD

Even I lost track.
Member Since: Posts: Comments:
Quoting EricSFL:

And if you look closely, you can also see Bimini.
I thought that too, but wasn't sure it wasn't just a different coloured dust spot on my screen... lol... like 1 pixel... lol
Member Since: Posts: Comments:
150 hours and not much change with the low, will contiue to montior it.
Member Since: Posts: Comments:
1352. EricSFL
Quoting BahaHurican:
Hey... u can see Freeport on that...

And if you look closely, you can also see Bimini. This is a better image showing the Keys and Bahamas, as well as the Moon's glare on the ocean.

Image Credit: NASA
Member Since: Posts: Comments:
126hrs has a 1009mb low at the cv islands
Member Since: Posts: Comments:
Quoting EricSFL:
Amazing view of Florida at night. Image credit: NASA
Hey... u can see Freeport on that...
Member Since: Posts: Comments:
120hrs
Member Since: Posts: Comments:

Viewing: 1399 - 1349

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 | 25 | 26 | 27 | 28 | 29 | 30 | 31Blog 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.

Local Weather

Overcast
42 °F
Overcast

JeffMasters's Recent Photos

Carrot Nose in Danger
Deep Snow in Brookline, MA
Sunset at Fort DeSoto
New Years Day Sunset in Death Valley