A heat wave recap; generally quiet tropics

By: Dr. Jeff Masters , 4:45 PM GMT on July 25, 2011

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Last week's U.S. heat wave has finally subsided, and most of the Northeast will see some cool highs in the 70s today. Unfortunately, the Midwest, and mid-Atlantic will continue to see high temperatures in the 90s for the rest of this week, and the southern Plains will be forced to continue to endure triple-digits.

According to the National Climatic Data Center (NCDC), 2,100 daily high maximum temperature records have been set so far in July 2011, and 51% of those were set last week. 4,734 daily high minimum temperature records have been set so far this month, and 55% of those were set last week. Here's a breakdown of last week's records for the period July 18 through July 24:

High Maximum:

• 1,076 warmest maximum temperature for the date
• 90 warmest maximum temperature for the month of July
• 56 warmest maximum temperature of all time

High Minimum:

• 2,595 warmest minimum temperature for the date
• 207 warmest minimum temperature for the month of July
• 123 warmest minimum temperature of all time

The number of warm minimum temperatures is especially disturbing, as these tend to have more of an impact on health than the high maximums. When the temperature remains high at night, it prevents the body from being able to recover from the day's heat. According to NOAA, from July 1 through July 19, there were 22 heat-related deaths in the United States. Reuters is reporting that 34 deaths resulted from this heat wave. In an average year, heat remains the number one weather-related killer in this country. In some ways, the overnight low temperatures are the best way to quantify a heat wave, possibly even better than the heat index.


Figure 1. Map of daily high maximum temperature records for the period July 1 through July 25 from NCDC. Red circles without an X denote a broken record; red circles with an X denote a tied record.

Tropical Overview

The wave formerly known as Invest 90L

The wave formerly known as Invest 90L is moving slowly west through the Caribbean near Jamaica. A new burst of convection started this morning, which will undoubtedly produce some heavy rain over southern Cuba and Jamaica. While low-level circulation has remained about the same since late last week, the wave has become top-heavy with increased circulation at higher levels (700-500mb). None of the models (GFS, ECMWF, CMC, NGPS, UKMET) are developing this wave as tracks into the Gulf of Mexico, and they're all in agreement that the path will be toward far southern Texas or northern Mexico, except for the ECMWF deterministic run, which hints that it will take a turn toward the northern Gulf. However, this model hasn't shown actual development from the wave since Tuesday or Wednesday of last week.

NHC has dropped this invest as of Saturday afternoon, but it remains on their radar. They're giving the wave a 0% chance to form over the next 48 hours. Given the recent uptick in mid-level circulation, I'd imagine they're still a little concerned about the potential for this wave to fire-up again once it's in the Gulf, and it will surely be of concern for Cuba as it tracks westward. However, given the lack of model support for almost 7 days in a row now, I'd say this wave has seen its glory come and go.


Figure 2. Visible tropical Atlantic satellite captured at 11:14am EDT on Monday.

Other North Atlantic waves

There are a couple other waves to speak of that have left the coast of Africa in the past few days, one located near 40W and the other closer to Africa, around 30W, which is tangled up in the monsoon trough. The former is expected to take a southerly track, skirting northern South America, and possibly into the Bay of Campeche. Given this track, none of the models are suggesting it will develop. However, tropical cyclones that spin up in the Bay of Campeche generally have a short forecast lead time, so it's something to watch. The latter wave could take a slightly more northern track through the Caribbean islands, and a couple of the models seem to favor this wave for development at the end of their runs.

Tropical wave activity has been lacking so far this season, but climatologically we should see an increase in African easterly waves in August and September.

Angela

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Quoting Tazmanian:
ex90L is RIP its been RIP whats move on too some in new too track
there's not much else to track though Taz

Few tropical waves, but none of them have a better chance of development at the moment
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x90L is RIP all the way
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Quoting TxHurricanedude11:

read post 870
Its called lack of patience and being confused!
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Quoting spathy:
I tend to agree.
"90L" looks better than it has.
I know thats like saying Phyllis Diller looks better than she ever has but.....!



its x90L
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Quoting washingtonian115:
The storm chasers will be happy this year If a storm(or few) would come to our shores.Well I don't like when it happens.We all know how the story of hurricane Katrina divided the country.
Which is sad, since it should instead have unified it. I like to think Louisianans have done better, by leading by example in times of trial [well most of 'em, anyway - tips hat at LAbloggers]. And IMO Portlight is one of the good things that, indirectly came from the tragedy of Katrina.
Member Since: October 25, 2005 Posts: 19 Comments: 22725
ex90L is RIP its been RIP whats move on too some in new too track
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Quoting yoboi:



just remember NHC can't cry wolf lots of politics keep that in mind........


Nothing to cry wolf about here.
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Quoting TxHurricanedude11:

read post 870



what is your point
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Quoting scott39:
Taz, I give up on xxxxxxxxx90L RIPPPPPPPPPPPP !!


YAY



any one us want too give up on 90L plzs say RIP
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Quoting muddertracker:
wth? Cangialosi wrote that? The world is comming to an end! I would expect at least 10% from Cangi...


I don't think he is the conservative one. When talking about conservation, Stewart is your guy.
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am with the nhc with this
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886. yoboi
Quoting Chucktown:
Just like we have seen over the last few days, storms have fired over the islands due to land/sea breeze interaction giving ex-90L the appearence of some development. Granted, there is some twist there, but this is a no go. I'd be surprised if the 8 PM TWOAT is anything different than 0% chance.



just remember NHC can't cry wolf lots of politics keep that in mind........
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Quoting Tazmanian:
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUL 25 2011

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

A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SEA CONTINUES TO PRODUCE
DISORGANIZED SHOWERS AND THUNDERSTORMS OVER CUBA...JAMAICA...THE
CAYMAN ISLANDS...AND THE NEARBY WATERS. ATMOSPHERIC CONDITIONS ARE
NOT EXPECTED TO BE CONDUCIVE FOR SIGNIFICANT DEVELOPMENT...AND THIS
SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT
10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOS





ahhhhhhhhhhhhhhhhhh why wont they drop this
Taz, I give up on xxxxxxxxx90L RIPPPPPPPPPPPP !!
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Quoting TropicalAnalystwx13:
Still at Near 0%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUL 25 2011

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

A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SEA CONTINUES TO PRODUCE
DISORGANIZED SHOWERS AND THUNDERSTORMS OVER CUBA...JAMAICA...THE
CAYMAN ISLANDS...AND THE NEARBY WATERS. ATMOSPHERIC CONDITIONS ARE
NOT EXPECTED TO BE CONDUCIVE FOR SIGNIFICANT DEVELOPMENT...AND THIS
SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT
10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOSI

What?!
Good Evening.
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Quoting TxHurricanedude11:
mr.c didnt see it so he made it up



????
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wth? Cangialosi wrote that? The world is comming to an end! I would expect at least 10% from Cangi...
Member Since: August 16, 2007 Posts: 1 Comments: 2351
Quoting FLdewey:

I want some of the pills you're taking... they must be wicked awesome. (that was with a boston accent)


haha never said i believed it though
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Just like we have seen over the last few days, storms have fired over the islands due to land/sea breeze interaction giving ex-90L the appearence of some development. Granted, there is some twist there, but this is a no go. I'd be surprised if the 8 PM TWOAT is anything different than 0% chance.
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wow! ex90l is really getting its act together! i have to say i'm impressed with all you regulars. you all called it before any news or weather channel. good job! my hats off to ya:)
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Still at Near 0%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUL 25 2011

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

A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SEA CONTINUES TO PRODUCE
DISORGANIZED SHOWERS AND THUNDERSTORMS OVER CUBA...JAMAICA...THE
CAYMAN ISLANDS...AND THE NEARBY WATERS. ATMOSPHERIC CONDITIONS ARE
NOT EXPECTED TO BE CONDUCIVE FOR SIGNIFICANT DEVELOPMENT...AND THIS
SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT
10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOSI
Member Since: Posts: Comments:
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUL 25 2011

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

A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SEA CONTINUES TO PRODUCE
DISORGANIZED SHOWERS AND THUNDERSTORMS OVER CUBA...JAMAICA...THE
CAYMAN ISLANDS...AND THE NEARBY WATERS. ATMOSPHERIC CONDITIONS ARE
NOT EXPECTED TO BE CONDUCIVE FOR SIGNIFICANT DEVELOPMENT...AND THIS
SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT
10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOS





ahhhhhhhhhhhhhhhhhh why wont they drop this
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Quoting FLdewey:
LOL Mudder... it should be RDB

It's not often I miss the joke...but I don't get this one? What's RDB?
Member Since: August 16, 2007 Posts: 1 Comments: 2351
Oh boy, Oh boy!

It's going to rain tonight :D
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You can't simply ignore something because it hasn't developed yet, it isn't over until this moves permanently over land or completely dissipates. Completely ignoring something is just plain daft and foolish.
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Quoting Neapolitan:

My, Taz, you are quick; that was up for all of ten seconds before I deleted the comment. No, ATCF hiccuped, which it does from time to time, and I was a bit too fast on the trigger. It happens... ;-)


ok lol
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Quoting Tazmanian:




they skip 91L lol

My, Taz, you are quick; that was up for all of ten seconds before I deleted the comment. No, ATCF hiccuped, which it does from time to time, and I was a bit too fast on the trigger. It happens... ;-)
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Quoting brazocane:


Rapid Intensification Possible

oh..lol
Member Since: August 16, 2007 Posts: 1 Comments: 2351
Quoting neutralenso:

now its 92L?!!?! what was the point of that?



Quoting Neapolitan:
Nevermind; ATCF glitch



this for that i got some crow for him
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Quoting muddertracker:

rapid infrared progress?


Rapid Intensification Possible
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Quoting P451:


It's still too close to land to significantly organize - also eastern Cuba does have high mountains to contend with.

However it has become gradually better organized throughout the day. Also doing a few things it had not yet done through it's history. So I'd look for persistence.

The big things for me is if it will maintain convection and take advantage of DMax - or will it repeat history of fading once day time heading ends. Whether or not the mid level vorticity will now work it's way down to the surface since we do have a discernible surface feature and we do now have surface convergence and better divergence aloft - two things we also had not had the past couple of days.

It's got a ways to go but for the first time in ~3 days it appears to be organizing.

Quoting P451:


It's still too close to land to significantly organize - also eastern Cuba does have high mountains to contend with.

However it has become gradually better organized throughout the day. Also doing a few things it had not yet done through it's history. So I'd look for persistence.

The big things for me is if it will maintain convection and take advantage of DMax - or will it repeat history of fading once day time heading ends. Whether or not the mid level vorticity will now work it's way down to the surface since we do have a discernible surface feature and we do now have surface convergence and better divergence aloft - two things we also had not had the past couple of days.

It's got a ways to go but for the first time in ~3 days it appears to be organizing.

Thanks for the explanation. Why is the NHC so low on its % to develope?
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Quoting muddertracker:
Link

LSU low cloud product...improvement, yes....there yet? not even close.


Whoa! Look at that blow-up over S Florida!
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Link

LSU low cloud product...improvement, yes....there yet? not even close.
Member Since: August 16, 2007 Posts: 1 Comments: 2351
Quoting Neapolitan:
Nevermind; ATCF glitch



dran you lol
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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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