Midwest heat wave generates a heat index of 131° in Iowa; Bret no threat

By: Dr. Jeff Masters , 1:18 PM GMT on July 19, 2011

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A unusually intense, long-lasting, and widespread heat wave with high humidities continues to plague the Central U.S. The heat index--how hot the air feels when factoring in both the temperature and the humidity--exceeded 100°F in twelve states on Monday and thirteen on Sunday, with the dangerous heat extending from Texas northwards to North Dakota, Minnesota, and Wisconsin. At least thirteen deaths are being blamed on the heat in the Midwest. The heat index hit a remarkable 131°F at Knoxville, Iowa on Monday, and a heat index in excess of 120° was recorded at numerous locations in Iowa, Minnesota, and Illinois.


Figure 1. Predicted maximum heat index for Thursday, July 21, 2011. Portions of 33 states are predicted to have a heat index in excess of 100°F. Image credit: NOAA.

A 1-in-7-year heat wave coming for the Eastern U.S.
The extreme heat will shift slowly eastwards this week, peaking in Chicago on Wednesday, Detroit and Pittsburgh on Thursday, and New York City and the mid-Atlantic states on Friday. Temperatures near 100°F are expected in Detroit on Thursday and New York City on Friday. Detroit has hit 100°F 18 different years in its 137-year record, and New York City 22 years out of the past 140 years, so this heat wave is expected to be about a 1 in 7 year event. While that makes it a notable heat wave, the most remarkable feature of this July 2011 U.S. heat wave is the humidity that has accompanied the heat. A heat index over 130°F, such as was observed yesterday in Iowa, is very rare in the U.S., and extremely dangerous. According to Christopher C. Burt, wunderground's weather historian, the only place in the world where a heat index over 130°F is common is along the shores of the Red Sea in the Middle East. A major reason for the remarkably high humidities accompanying the July 2011 Midwest heat wave is the record flooding the region experienced over the past three months. As pointed out by wunderground's climate change blogger Dr. Ricky Rood in his latest post, with hundreds of thousands of acres of farmland still inundated by flood waters, and soils saturated over much of the Upper Midwest, there has been plenty of water available to evaporate into the air and cause remarkably high humdities. This makes for a very dangerous situation, as the human body is not able to cool itself as efficiently when the humidity is high. The extreme heat will last through Sunday in the mid-Atlantic, but should end on Monday, when a cold front is expected to sweep across the region. However, the latest models suggest the heat will re-amplify over the Midwest next week.


Figure 2. Tropical Storm Bret at peak intensity, at 5:15 pm EDT on Monday, July 18, 2011. At the time, Bret was building an eyewall and had begun to clear out an eye. Image credit: NASA/GSFC.

Tropical Storm Bret weakens
Tropical Storm Bret enjoyed a brief burst of intensification yesterday afternoon that brought the storm's winds up to 65 mph. However, Bret has sucked in a lot of dry air today, and is now a much weaker storm with winds of just 50 mph. Satellite imagery shows that Bret has not improved in organization this morning, thanks to dry air to the northwest that has been blown into the storm's core by upper-level northwesterly winds. Wind shear is a high 20 - 25 knots, and is expected to remain in the high range for the next three days. The combination of high wind shear and dry air nearby should act to keep Bret from strengthening, and the storm should slowly decay as it heads out to sea over the next few days. Bret is not a threat to any land areas.

None of the reliable models predict tropical cyclone development over the remainder of the Atlantic through July 26.

Weakened Typhoon Ma-on nearing Japan
Typhoon Ma-on has weakened to minimal Category 1 typhoon with 75 mph winds, and is battering a large swath of the south coast of Japan with tropical storm-force winds, as the storm slides northeast along the coast. Ma-on is expected to turn eastwards out to sea by Wednesday, and is not likely to bring tropical storm-force winds to the troubled Fukushima Nuclear Plant.

Jeff Masters

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635. beell
Quoting BahaHurican:
There's still Canada and the Azores out there... and I suppose if u really want to get technical the Iberian peninsula and the British Isles...


Sometimes it's Dept. of Defense assets that makes it worth a closer INVESTigation. Navy, etc.
Member Since: September 11, 2007 Posts: 148 Comments: 17284
Quoting BahaHurican:
Thanks Taz.

I note the EPac is 4 for 5.... wonder how much longer that will last...





not sure
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
I think their's a chance 99L could become a storm.Well Sub-tropical in nature.That's MOO(My opinion only).
Member Since: Posts: Comments:
Quoting FrankZapper:
Sometimes I detect a subtle wishing on this blog that CONUS gets hit by a hurricane. There seems to be frustration right now for instance, that nothing is threatening the US. But then it is a hurricane blog.
true
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There is good outflow on the eastern side of 99L, and I do not think it is the outflow that means thunderstorms are collapsing.

Member Since: July 6, 2010 Posts: 113 Comments: 33442
Bret is trying his best to refire convection over his circulation, but that shear is doing a number on him.
Member Since: October 3, 2010 Posts: 40 Comments: 4129
I think the Doc can post that all the time now because one of us is down here in the comments going,

"But Doc! What about 9?L out there, just waiting for u to say that to spin up????"

LOL

Seriously, though, isn't next development projected for sometime after the weekend?
Member Since: October 25, 2005 Posts: 19 Comments: 22830
Quoting RukusBoondocks:
None of the reliable models predict tropical cyclone development over the remainder of the Atlantic through July 26

Every time he says that another invest pops up LOL


Ha ha..I think though the atlantic has a mind of its own now..
Member Since: Posts: Comments:
Quoting snotly:
Don't you mean wel come?



sure what you this said lol
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
Sometimes I detect a subtle wishing on this blog that CONUS gets hit by a hurricane. There seems to be frustration right now for instance, that nothing is threatening the US. But then it is a hurricane blog.
Member Since: Posts: Comments:
Quoting BahaHurican:
Thanks Taz.

I note the EPac is 4 for 5.... wonder how much longer that will last...

maybe the east pacific will have a record for most hurricanes forming in a year?
Member Since: Posts: Comments:
Quoting HurricaneDean07:
Everyone meet 99L, Say goodbye to her in a couple of hours, cuase she is not gonna last long...
Bad call by the NHC...


? What is the basis for your claim?
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Quoting HurricaneDean07:
Everyone meet 99L, Say goodbye to her in a couple of hours, cuase she is not gonna last long...
Bad call by the NHC...


Wrong sir!

*Slaps you with a fish*
Member Since: July 6, 2010 Posts: 113 Comments: 33442
Don't you mean wel come?

Quoting Tazmanian:



welcome
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Quoting HurricaneDean07:
Everyone meet 99L, Say goodbye to her in a couple of hours, cuase she is not gonna last long...
Bad call by the NHC...


I disagree, highly. I called this several days ago actually and this is a legit threat to develop very soon as it just needs to separate from the trough. Looks like it has 24-48 hours of warm water left to. If anything, this call should have been made a few hours ago.
Member Since: July 8, 2005 Posts: 259 Comments: 24682
Thanks Taz.

I note the EPac is 4 for 5.... wonder how much longer that will last...

Member Since: October 25, 2005 Posts: 19 Comments: 22830
Quoting NICycloneChaser:


Nope, they were just explaining something about their previous post. No designation yet.
Ohhh okay.
Member Since: Posts: Comments:
Everyone meet 99L, Say goodbye to her in a couple of hours, cuase she is not gonna last long...
Bad call by the NHC...
Member Since: October 3, 2010 Posts: 40 Comments: 4129
None of the reliable models predict tropical cyclone development over the remainder of the Atlantic through July 26

Every time he says that another invest pops up LOL
Member Since: February 13, 2011 Posts: 0 Comments: 294
Quoting NICycloneChaser:


Not too concerned up here in the British Isles just yet.... :P
I hear the Irish are running out to McLowes... lol

Member Since: October 25, 2005 Posts: 19 Comments: 22830
Quoting Vincent4989:
I don't know why, but the text on this page seems to be larger and more rounded that usual, with the exception of comments, it looks like the font is verdana, a very common font in forums.



you can thank dr m for that
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
Quoting HurricaneDean07:
Invest 99L... ?
Bad call....
just another Bust invest it appears.



nop good call i have seen many TS and STS from out here i can even name a few
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
611. DDR
Quoting Vincent4989:
Nope, you might have yo ur settings different. sort to "Order Posted" to return to normal.

Thanks,i should have figured that out.
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I don't know why, but the text on this page seems to be larger and more rounded that usual, with the exception of comments, it looks like the font is verdana, a very common font in forums.
Member Since: Posts: Comments:
Invest 99L... ?
Bad call....
just another Bust invest it appears.
Member Since: October 3, 2010 Posts: 40 Comments: 4129
Quoting TomTaylor:
Thanks Taz



welcome
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
Quoting BahaHurican:


This is what's got me thinkin'....

Don't want this to get set as the pattern, because minor variations to the east or west [especially west] could mean significant landfall potential for most of the northern Caribbean, TCI, Bahamas, and East Coast US.

I'm wondering where that mean trough is likely to set up. That could be a boon or a curse, depending on exact location at the time a storm approaches the area...


Looks like to me 99L will get turn around with that big High set up in the middle of the atlantic..
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Quoting Tazmanian:
i post a update


1st US

round 1


90L bust

91L bust

92L bust

93L bust

94L bust

95L be comes ARLENE

96L bust

97L bust

98L be comes BERT

99L ?


round 2




here the E PAC



round 1



90E bust

91E be comes ADRIAN

92E be comes BEATRIZ

93E be comes CALVIN

94E be comes DORA





Thanks Taz
Member Since: Posts: Comments:
Quoting help4u:
Taz,spotted any pin-hole eyes yet?



lol
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
Quoting washingtonian115:
Huh?.I'm totally confused to.Is this true?


Nope, they were just explaining something about their previous post. No designation yet.
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Quoting NICycloneChaser:


Don't worry, I'll go put up the shower curtain.



i go put on my dress
Member Since: May 21, 2006 Posts: 5091 Comments: 115605


This is what's got me thinkin'....

Don't want this to get set as the pattern, because minor variations to the east or west [especially west] could mean significant landfall potential for most of the northern Caribbean, TCI, Bahamas, and East Coast US.

I'm wondering where that mean trough is likely to set up. That could be a boon or a curse, depending on exact location at the time a storm approaches the area...
Member Since: October 25, 2005 Posts: 19 Comments: 22830
Taz,spotted any pin-hole eyes yet?
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Quoting Tazmanian:




LOL mode runs have it pointing at the UK so no fish


Don't worry, I'll go put up the shower curtain.
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Quoting NICycloneChaser:


Eh?
Huh?.I'm totally confused to.Is this true?
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Quoting NICycloneChaser:


I'm gonna be the first to call it.

FISH!!!!!

FISHBONES!!!!!!!!
Member Since: Posts: Comments:
Quoting NICycloneChaser:


I'm gonna be the first to call it.

FISH!!!!!




LOL mode runs have it pointing at the UK so no fish
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
Quoting Tazmanian:




hi


Yo..
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Quoting nrtiwlnvragn:


I had posted that 99L needs to detach from the front or the front dissipate in order to be designated. I should have added to the end "as a subtropical/tropical cyclone".


Ah, understood.

Had me worried for a second there.... Haha
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Quoting HCW:
a few more model runs from the NHC for 99L




I'm gonna be the first to call it.

FISH!!!!!
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Quoting NICycloneChaser:


Eh?


I had posted that 99L needs to detach from the front or the front dissipate in order to be designated. I should have added to the end "as a subtropical/tropical cyclone".
Member Since: Posts: Comments:
Quoting GiovannaDatoli:

Oh no. Not at all. You're one of the coolest people on here. It makes sense because your posts show up when I set the filter to "Show Best".
Thanks for that.Sometimes I missspell when I don't check what I'm typing ya know.It totally screws me over sometimes.
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591. HCW
a few more model runs from the NHC for 99L


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Quoting nrtiwlnvragn:


Designated as a tropical cyclone.




????
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
oh ok yes then
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Quoting mcluvincane:



Take it easy MATE.. Did not say it was the same set up. Goodday to you




hi
Member Since: May 21, 2006 Posts: 5091 Comments: 115605
Quoting nrtiwlnvragn:


Designated as a tropical cyclone.


Eh?
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Quoting mcluvincane:
1 storm to mexico, 2 out to sea.... is the CONUS shield up again or what? It seems every time a cylcone developes and heads towards the U.S., a trough digs down and wisps it out to sea. Almost every time last year and already happening again this year.
Yes Captain. Shields are at 100%. A photon torpedo couldn't even dent them.
Member Since: Posts: Comments:
Quoting Tazmanian:




will you plzs stop it we do not have the same setup has last year



Take it easy MATE.. Did not say it was the same set up. Goodday to you
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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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