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 Patrap:

When the Music's over



Uploaded by jessycalewilliamson on Feb 14, 2012

Jim Morrison's last night on stage with The Doors was at The Warehouse in New Orleans Louisiana on December 12, 1970. This short film uses interviews with The Warehouse owners, employees and a fan to tell the story of what really happened that night. This is a small portion of my larger documentary "A Warehouse on Tchoupitoulas" which delves into all the goings on at New Orleans' most infamous music venue.


I never saw them... Though they were ahead of time and marked that decade...

Jefferson Airplane, Gratefull Death and others were in our ears...

Thanks for the Youtube link and the info...
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NHC wants to see if it detaches from the ITCZ.
Member Since: August 14, 2010 Posts: 10 Comments: 16971
JTWC's new warning on Saola is out... they kept it at 55kts:

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1267. maeko
Quoting maeko:
Hey, is it just me (which is highly likely 'cause I'm no weather expert) or does the storm activity around the SC coast starting to look a little 'tropical'? Just curious...


I saw a couple posts of maps with a swirly thing...is that about what I was referring to? Or am I totally off-base?
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For me this is the path of ernesto:

Yellow 20%
Orange 30%
Red 50%
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1265. KEEPEROFTHEGATE (Mod)
POSS T.C.F.A.
XX/INV/99L
MARK
9.8795N/36.40W


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Quoting TropicalAnalystwx13:
This should be up to 40%.



NHC will downplay and say 20% still.
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Quoting washingtonian115:
It took are sanity away from us..


Yeah, right into the swirling vortex of confusion.
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Quoting sunlinepr:


Track is highly uncertain at least until 99L develops...
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This should be up to 40%.

Member Since: July 6, 2010 Posts: 113 Comments: 32023
Quoting nofailsafe:
I really just hope that if anything develops from this disturbance that The Cone for this storm is better defined than that of Debby. Ugh. Uncertainty is expensive.
It took are sanity away from us..
Member Since: August 14, 2010 Posts: 10 Comments: 16971
Quoting JRRP:
red color tomorrow... IMO


That quick? Not so fast.
Member Since: April 29, 2009 Posts: 75 Comments: 14252
I really just hope that if anything develops from this disturbance that The Cone for this storm is better defined than that of Debby. Ugh. Uncertainty is expensive.
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Quoting JRRP:
red color tomorrow... IMO


nop
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Quoting JrWeathermanFL:
99L could follow a track like Earl in 2010 or possibly Irene in 2011 IMO.
Or Floyd..Did I dare say the name?.Lol.
Member Since: August 14, 2010 Posts: 10 Comments: 16971
99L could follow a track like Earl in 2010 or possibly Irene in 2011 IMO.
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1254. JRRP
red color tomorrow... IMO
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Quoting MAweatherboy1:

Geography isn't my strength :)


some decent effects on Nova Scotia if this pulls through. Long runs of the models love giving Nova Scotia a big one and they fail almost all of the time.
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1252. Patrap
Thats creepy sunlinepr..

Jims last show was here a long time ago, about 2 miles from where I live here.



When the Music's over



Uploaded by jessycalewilliamson on Feb 14, 2012

Jim Morrison's last night on stage with The Doors was at The Warehouse in New Orleans Louisiana on December 12, 1970. This short film uses interviews with The Warehouse owners, employees and a fan to tell the story of what really happened that night. This is a small portion of my larger documentary "A Warehouse on Tchoupitoulas" which delves into all the goings on at New Orleans' most infamous music venue.
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Florence is that you?!?.
Member Since: August 14, 2010 Posts: 10 Comments: 16971
I wouldn't be too much surprised if 99l (should it develops) affects the same islands as hurricane Earl did : the northern lesser antilles, then the virgin islands, then turning north west and avoiding the bahamas; we shall see what happens...
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384HR
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1247. KEEPEROFTHEGATE (Mod)
Quoting pottery:

It's been pretty dry last week or so.
Some rains would be nice, actually.
Nice, gentle soakers.

See you Tomorrow....
i will see what i can do
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Quoting MAweatherboy1:
Second one wants to pay TA 13 a visit:


Well isn't that nice of it.
Member Since: July 6, 2010 Posts: 113 Comments: 32023
Ok, me and MA had the same idea and posted the same image at the same time so I removed my image.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
Second one wants to pay TA 13 a visit:

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Quoting Patrap:
..and now, the end is near, I feel I face, my final Blog post..


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Quoting WeatherNerdPR:

It's hitting Newfoundland, not Nova Scotia. :P

Geography isn't my strength :)
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Quoting MAweatherboy1:
The 18z GFS individual ensemble members are coming in... First one wants fish:



And Nova Scotia:


It's hitting Newfoundland, not Nova Scotia. :P
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1239. pottery
Quoting washingtonian115:
i think it'll be close enough to bring some rain to you guys.

It's been pretty dry last week or so.
Some rains would be nice, actually.
Nice, gentle soakers.

See you Tomorrow....
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1238. hydrus
Quoting SFLWeatherman:
Now it going S FL!!
One model takes it into southern Costa Rica, and another recurves it close to Bermudy..Model spread is fierce. When they slap a moniker on 99, da models will tighten there grip and nail the suckah.
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1237. KEEPEROFTHEGATE (Mod)
925

WHXX01 KWBC 310032

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS NATIONAL HURRICANE CENTER MIAMI FL

0032 UTC TUE JUL 31 2012



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



DISTURBANCE INVEST (AL992012) 20120731 0000 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

120731 0000 120731 1200 120801 0000 120801 1200



LAT LON LAT LON LAT LON LAT LON

BAMS 8.9N 36.6W 9.5N 39.9W 10.0N 43.3W 10.1N 47.0W

BAMD 8.9N 36.6W 9.1N 38.6W 9.6N 40.6W 10.1N 42.5W

BAMM 8.9N 36.6W 9.4N 38.8W 10.0N 41.2W 10.6N 43.5W

LBAR 8.9N 36.6W 9.1N 38.7W 9.6N 41.3W 9.9N 44.0W

SHIP 20KTS 24KTS 30KTS 40KTS

DSHP 20KTS 24KTS 30KTS 40KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

120802 0000 120803 0000 120804 0000 120805 0000



LAT LON LAT LON LAT LON LAT LON

BAMS 9.7N 50.4W 8.9N 56.6W 8.2N 62.2W 8.5N 66.9W

BAMD 10.6N 44.5W 11.5N 48.3W 13.1N 52.7W 15.4N 58.0W

BAMM 11.1N 45.8W 11.9N 50.3W 12.9N 55.1W 14.0N 60.4W

LBAR 10.1N 46.6W 10.2N 51.8W 10.6N 56.4W 12.7N 59.2W

SHIP 47KTS 60KTS 66KTS 66KTS

DSHP 47KTS 60KTS 66KTS 66KTS



...INITIAL CONDITIONS...

LATCUR = 8.9N LONCUR = 36.6W DIRCUR = 280DEG SPDCUR = 8KT

LATM12 = 8.7N LONM12 = 35.5W DIRM12 = 270DEG SPDM12 = 3KT

LATM24 = 8.7N LONM24 = 34.7W

WNDCUR = 20KT RMAXWD = 80NM WNDM12 = 20KT

CENPRS = 1010MB OUTPRS = 1011MB OUTRAD = 150NM SDEPTH = S

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN
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The 18z GFS individual ensemble members are coming in... First one wants fish:



And Nova Scotia:

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1235. pottery
I have to check my shower curtains.
You all keep an eye on things!

Laters>>>>>>>>>>>>>>>>>>>>>>>>
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Quoting pottery:

Yeah, I'm seeing that possibility.
It's not unusual for one of two things to happen in these cases...

1) it passes north and drags the moisture with it leaving us dry for 10 days.

2) It is close enough to bring real heavy rain here.

I'm rooting for #1.
i think it'll be close enough to bring some rain to you guys.
Member Since: August 14, 2010 Posts: 10 Comments: 16971
Quoting spathy:


Its not good to second guess Mother Nature?

Ma Nature is way older.
She has ways of doing things that she has been doing for ever!

There might be some day when we get closer to understanding her path.

For now we just speculate with the tidbits we think we have uncovered recently.


On a serious tone, true...

We rely on all this technology to observe and try to pronosticate or like you wrote, understand her path or the way Nature will behave and we always get surprises...
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1232. Patrap
..a Lil Elvis is all.

In honor of Civccane49 departure
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Quoting washingtonian115:
The faster 99L develops the quicker it'll make it's turn north.It appears to be developing at a good clip.Now don't be surprised to see a strong tropical storm impacting the islands mid-week.


115,it will take a little more time to arrive at the islands by friday is a better estimate.
Member Since: April 29, 2009 Posts: 75 Comments: 14252
1230. pottery
Quoting washingtonian115:
The faster 99L develops the quicker it'll make it's turn north.It appears to be developing at a good clip.Now don't be surprised to see a strong tropical storm impacting the islands mid-week.

Yeah, I'm seeing that possibility.
It's not unusual for one of two things to happen in these cases...

1) it passes north and drags the moisture with it leaving us dry for 10 days.

2) It is close enough to bring real heavy rain here.

I'm rooting for #1.
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Quoting Articuno:
99L

Earlier:


Now:



Definitely strengthening, could have a TD by Tues. Afternoon.


Wednesday evening at the earliest IMO.
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1228. Patrap
00z Early Cycle NHC model tracks
Invest99

Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)




Early Model Wind Forecasts

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99L

Earlier:


Now:



Definitely strengthening, could have a TD by Tues. Afternoon.
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1226. Grothar
Member Since: July 17, 2009 Posts: 71 Comments: 26118
??? why???
Quoting Patrap:
..and now, the end is near, I feel I face, my final Blog post..
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Quoting GeorgiaStormz:


beryl already took that
I thought it was Debby.
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Quoting Civicane49:


I have to go because I have a lot of work to do starting tomorrow. I will try to come back from time to time, if time permits.

Goodbye.
going to miss you and your blog hope you can come more frequent take care.
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Quoting pottery:

They generally do!
The joys of living at 11n.

(hope I have not crapped on my own front-step, there. LOL)
The faster 99L develops the quicker it'll make it's turn north.It appears to be developing at a good clip.Now don't be surprised to see a strong tropical storm impacting the islands mid-week.
Member Since: August 14, 2010 Posts: 10 Comments: 16971
1221. Patrap
..and now, the end is near, I feel I face, my final Blog post..
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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.