African tropical wave 99L has potential to develop

By: Dr. Jeff Masters , 3:10 PM GMT on July 30, 2012

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The first African tropical wave of 2012 with a potential to develop is Invest 99L, located in the Eastern Atlantic near 9°N 36°W, midway between the Lesser Antilles Islands and the coast of Africa. Visible satellite loops show a large area of the surrounding atmosphere has a pronounced counter-clockwise spin, though there is no surface circulation. The disturbance's heavy thunderstorm activity is pretty sparse, but appears to be slowly increasing. Water vapor satellite loops show that 99L has a reasonably moist environment, and the latest Saharan air layer analysis shows that the dry air from the Sahara lies well to the north of 99L. WInd shear over the disturbance is a light 5 - 10 knots, and ocean temperatures are 28°C, (82°F) which is well above the 26.5°C (80°F) threshold typically needed to allow formation of a tropical depression.


Figure 1. Morning satellite image of Invest 99L.

Forecast for 99L
Wind shear is expected to remain light for the next five days, and ocean temperatures will remain near 28°C, according to the 8 am EDT run of the SHIPS model. The disturbance is at 9°N, which is close enough to the Equator that the storm will have some difficultly getting spinning. Most of the models are showing some slow development of 99L, with the storm reaching the Lesser Antilles Islands on Saturday, August 3. NHC gave 99L a 20% chance of developing into a tropical depression by Wednesday morning. I expect the storm will have trouble with dry air at times this week as it crosses the Atlantic, but I give 99L a 50% chance of eventually developing into Tropical Storm Ernesto sometime in the next ten days. Residents and visitors to the Lesser Antilles Islands should anticipate heavy rains and strong winds from 99L beginning to affect the islands as early as Friday night. The long-range fate of 99L is uncertain, but a trough of low pressure is expected to be present over the Eastern U.S. early next week, which would be capable of turning 99L more to the northwest.

Hot in the Central U.S.
The heat in America's heartland continued on Sunday, with Wichita, KS hitting 111°F, just 3° short of their all-time hottest temperature of 114° set on 8/12/1936. Other notable highs on Sunday:

111° Coffeyville, KS
111° Winfield, KS
110° Chanute, KS
110° Parsons, KS
109° Joplin, MO (all-time record is 115° on July 14, 1954)

The low temperature in Tulsa, Oklahoma this Monday morning dropped to only 88°F. This is the all-time warmest low temperature in the city since record keeping began in 1905. The previous record warmest minimum temperature was 87°F set on August 2, 2011 and July 16, 1980. The high in Tulsa Monday - Wednesday is expected to reach 110° - 111°, close to the city's all-time hottest temperature of 115° set on August 10, 1936.

Jeff Masters

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Quoting TropicalAnalystwx13:

Wind shear is not an issue, trade winds are.
And if 99L goes into the Caribbean the trade winds rip it apart.
Member Since: March 16, 2012 Posts: 127 Comments: 7927
Quoting wunderkidcayman:
Hey guys remember that I said that shear will drop in the caribbean well I am not the only one to say it after watching The Weather Channels Tropical Update and they talk about the wind shear droping and they have a forecast graphix to show what I mean if you want see what I am talking about watch it and skip to 00:45 sec and you will see it and then play the vid

Link

Wind shear is not an issue, trade winds are.
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Quoting HurricaneDean07:

Currently, only 2 models out of the 7 support movement north of the islands.


I dont think they mean in terms of concensus or what will happen, but in terms of strength

if 99L goes into the Caribbean it is going to get sheared to bits, its why the GFS constantly is showing it dying out there. If it goes north of the Islands, it will be stronger
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Corrected my mistake, I've belived a close to US landfall/ US landfall. I just didn't want to go over the blob of the Carolinas.
Member Since: March 16, 2012 Posts: 127 Comments: 7927
Quoting LargoFl:
..still have to watch that blob off the carolina's


Definitely a blob.

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215. Skyepony (Mod)
ASCAT Leeward Islands, missed 99L.
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Quoting stormchaser19:


looks like north path is the best way to 99l

Currently, only 2 models out of the 7 support movement north of the islands.
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Quoting Waltanater:
This would be the right blog to post this in right?

Get ready to pay more for your steak!

http://money.cnn.com/2012/07/30/pf/food-prices-dr ought/index.htm?hpt=hp_t2


There will be food riots throughout the developing world later this year and next, because of the drought pushing up grain prices. And it won't be the price of steak they'll be rioting about.
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Hey guys remember that I said that shear will drop in the caribbean well I am not the only one to say it after watching The Weather Channels Tropical Update and they talk about the wind shear droping and they have a forecast graphix to show what I mean if you want see what I am talking about watch it and skip to 00:45 sec and you will see it and then play the vid

Link
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test
Member Since: September 30, 2007 Posts: 9 Comments: 15932
Quoting ncstorm:
Nogaps..finished run..







looks like north path is the best way to 99l
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Too much attention is being placed on tracks considering there is no discernable center of circulation on 99L on which to base possible tracks.

I would assign a low confidence level on any track at this stage of 99L's development.
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Quoting ncstorm:
Nogaps..finished run..





Quoting ncstorm:
Nogaps..finished run..





Taking it toward SE Coast... going to be a close call.
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Thank you for the tropical update on 99L Dr, Masters. IMO it needs to gain some latitude if it's going to spin up. But it sure is great to have something to watch, even if it's way the heck out there now
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Quoting HurricaneDean07:

I dont think the 2nd path, would take 99L out to sea, the closest chance 99L has to recurve is, scraping the east coast...
The 2nd path isnt exact, it is just showing two separate paths. I realized that and I think a re-curve would take 99L very close to the east coast.
Member Since: March 16, 2012 Posts: 127 Comments: 7927
Quoting wxchaser97:


It's not going out to sea.. The ridge is too strong, possibly skirts the East Coast but not recurving that far east.
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204. Skyepony (Mod)
Leelee~ That wave approaching PR now should give them some rain tomorrow, Hispaniola on Wednesday..should get even more. Breaks up a bit on Cuba. Then heavier rains for the Bahamas (thurs into Fri) & increased chance of rain for FL (Fri & sat).

This wave looks more moist than expected a few days ago. Still choking a bit on dust but probably more rain than originally expected.
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.........................GFS at 60 Hours
Member Since: August 6, 2011 Posts: 4 Comments: 36880
This is what drought looks like:

http://ireport.cnn.com/topics/810896?hpt=hp_t2
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Quoting wxchaser97:

I dont think the 2nd path, would take 99L out to sea, the closest chance 99L has to recurve is, scraping the east coast...
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Nogaps..finished run..





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This would be the right blog to post this in right?

Get ready to pay more for your steak!

http://money.cnn.com/2012/07/30/pf/food-prices-dr ought/index.htm?hpt=hp_t2
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.........................GFS at 48 hours
Member Since: August 6, 2011 Posts: 4 Comments: 36880
Quoting Patrap:
O Lordy..

O Admin, most high, grant us a reprieve from idiocy this day.

Thanks be to Invest 99L.

"Ohmmm"


Ya know, it wouldnt be so bad if these trolls showed some degree of intelligence, but none seems available for them. Maybe if they studied instead of posting we could tolerate trolls rather than report them..
Member Since: September 27, 2007 Posts: 1 Comments: 20505
Member Since: March 16, 2012 Posts: 127 Comments: 7927
Member Since: August 6, 2011 Posts: 4 Comments: 36880
Quoting LargoFl:
..this is the one I am watching,radar off NC shows some rotation,surprising it doesnt have an invest yet
It is non tropical so no circle not every thunderstorm off the coast gets a circle
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Quoting TropicalAnalystwx13:
Regardless...

Blob, don't even attempt it.

So it's missing two wind directions to be closed... should be interesting since we're both under this blob.
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Quoting ncstorm:
surface low forming near Georgia

..this is the one I am watching,radar off NC shows some rotation,surprising it doesnt have an invest yet
Member Since: August 6, 2011 Posts: 4 Comments: 36880
So we finally got something in Atlantic huh? And got a chance to be a strong East Coast storm, eh? Hopefully it's not Irene part 2 or Earl part 2.
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.............................wow north Florida is lighting up big time
Member Since: August 6, 2011 Posts: 4 Comments: 36880
surface low forming near Georgia

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Regardless...

Blob, don't even attempt it.

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187. Skyepony (Mod)
Tail of the Carolina blob firing up a line of showers across North & Central Florida today. Click pic for animation.



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Quoting JrWeathermanFL:
At 2PM:
A. Yellow circle on 99L and NC Blob
B. Yellow circle on 99L
C. Orange circle on 99L
D. Orange circle on 99L and Yellow circle on NC Blob
E. Other

Just give opinions

Im gonna go out on a limb and say
99L is given a 30%.
and the Carolina blob is given a 10%.
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lol
Quoting sunlinepr:
Here comes the BLOB, with his mouth open....

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Member Since: August 6, 2011 Posts: 4 Comments: 36880
B
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B or C!! but C for now
Quoting JrWeathermanFL:
At 2PM:
A. Yellow circle on 99L and NC Blob
B. Yellow circle on 99L
C. Orange circle on 99L
D. Orange circle on 99L and Yellow circle on NC Blob
E. Other

Just give opinions
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SHIPS bringing 99L up to 75 knots at day 5.

It appears we might be getting 90L very soon off the east coast, as well...
Very interesting couple of days ahead of us.
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Quoting leelee75k:
What's up with the wave near PR and the islands?
Any chance of homegrown development with it?
where is it heading? Florida? Texas?
I would like a rainy weekend if I can have one
Unfortunately, the masses in this blog don't do requests! LOL.
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99L looks to be getting a tighter center!!
Link
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Quoting MississippiWx:
Surprise surprise. Another frontal development possible.


It's just rain moving ashore. That's what my NWS said anyways.
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123 BahaHurican: ...it's possible for storms to regenerate and come back strong even after crossing Hispaniola or eastern Cuba.

As long as you're giving examples: Ike crossed easternCuba, then grew to GINORMOUS proportions.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
Quoting JrWeathermanFL:
At 2PM:
A. Yellow circle on 99L and NC Blob
B. Yellow circle on 99L
C. Orange circle on 99L
D. Orange circle on 99L and Yellow circle on NC Blob
E. Other

Just give opinions


B
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Quoting MississippiWx:
Surprise surprise. Another frontal development possible.

..watching that one closely
Member Since: August 6, 2011 Posts: 4 Comments: 36880
I see some people have been listening to Levi's blog post.
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Quoting wxchaser97:
..THE ACTIVITY OVER E
CARIBBEAN AND THE LESSER ANTILLES IS DUE TO THE TROPICAL WAVE
JUST E OF THE ISLANDS
Member Since: August 6, 2011 Posts: 4 Comments: 36880
Quoting TropicalAnalystwx13:
Storm says that 99L needs to enter the Caribbean to survive and that if it moves north of the islands, wind shear will rip it apart.

Levi says that 99L needs to move north of the islands to survive and that if it moves into the Caribbean, trade winds will rip it apart.

:\

So basically no one really knows what will happen, kind of like Debby.
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Member Since: March 16, 2012 Posts: 127 Comments: 7927
At 2PM:
A. Yellow circle on 99L and NC Blob
B. Yellow circle on 99L
C. Orange circle on 99L
D. Orange circle on 99L and Yellow circle on NC Blob
E. Other

Just give opinions
Member Since: Posts: Comments:

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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.