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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Overall:
I give 99L a 65% chance of formation into a tropical cyclone...
and a 40% chance of it forming within the next 48 hours.
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dont.want.99.in.the.nw.carib.or.gulf
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Quoting JrWeathermanFL:
I say 99L makes it to 60 mph if it goes in the carribbean

I say 99L makes it to 70 mph if it goes to hispanola

I say 99L makes it to a cat one if it misses the carribbean

I say a bunch dont i?

Maximum intensity for this storm is Category 2. If it can cleanly get away from the caribbean islands...
If it goes through the caribbean it should only reach 60 mph TOPS. and if it goes through the northern caribbean islands it might get to 70 mph.. might not.
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Quoting Bluestorm5:
Just finished making my forecast. This is the second time I've created forecast (Emilia was first), but first time with the keys. Hope y'all like it! As for the forecast, I've created narrow cone because it's gonna stay going west/northwest most of the time until around HR 96. From there, the cone get wider. I really think 99L will be a slow organizing storm so I stick with the tropical storm forecast 120 hours from now. I didn't forecasts any farther than 120 hours because things changes pretty quickly. I do think this storm will go over the eastern edge of Hispaniola as a 70 mph tropical storm and weaken to 60 mph tropical storm before regaining strength to low Category 1 toward SE USA, but things changes pretty fast in the tropics. Again, this is not OFFICIAL FORECAST.


Right around my forecast:
"
I like your map Blue, it looks cool and is easy to read.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
1416. Grothar
Quoting Huracaneer:


That's a cool link! It's weird how some years were insanely active and then nothing for a dozen years. Random? or is there a pattern?


I believe it had a lot to do with the abandonment of so many Spanish settlements, especially in Puerto Rico. Therefore, very little was reported from certain areas. It had remained a little of a mystery why the 16th century had so many and the 17th didn't. Then historians began to look at the turmoil of the period and realized there were very few people left to report them and communications were not that great between the
British and the Spanish settlements. They occurred, but no one reported them. I would have, but my Spanish was not that good in those days.
Member Since: July 17, 2009 Posts: 71 Comments: 26118
Were right on par with 2011 it appears...
Emily formed on August 1st (Remembering off the top of my head), and we should get Ernesto around that time as well.
Good night everyone.
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I say 99L makes it to 60 mph if it goes in the carribbean

I say 99L makes it to 70 mph if it goes to hispanola

I say 99L makes it to a cat one if it misses the carribbean

I say a bunch dont i?
Member Since: Posts: Comments:
Whoops... should have time stamped it at 23:30 and not 11:30... oh well.
Member Since: August 1, 2011 Posts: 28 Comments: 8007
1412. 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

Member Since: July 3, 2005 Posts: 424 Comments: 128259
NHC models for develops

Member Since: June 20, 2012 Posts: 0 Comments: 2159
1410. JLPR2
Quoting Bluestorm5:
Just finished making my forecast. This is the second time I've created forecast (Emilia was first), but first time with the keys. Hope y'all like it! As for the forecast, I've created narrow cone because it's gonna stay going west/northwest most of the time until around HR 96. From there, the cone get wider. I really think 99L will be a slow organizing storm so I stick with the tropical storm forecast 120 hours from now. I didn't forecasts any farther than 120 hours because things changes pretty quickly. I do think this storm will go over the eastern edge of Hispaniola as a 70 mph tropical storm and weaken to 60 mph tropical storm before regaining strength to low Category 1 toward SE USA, but things changes pretty fast in the tropics. Again, this is not OFFICIAL FORECAST.



It is interesting that is your forecast, check CLIP5, which is a climatology based model.


Pretty much the same, lets see if climatology wins.
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The NHC's descriptions of the AOI are becoming lengthier each Discussion:
Atlantic Tropical Weather Discussion
------------------------------------------------- -------------------------------


000
AXNT20 KNHC 302351
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON JUL 30 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 17N36W TO A 1009 MB LOW AT 9N36W. THE WAVE/LOW IS MOVING W AT ABOUT 10-15 KT. THE WAVE IS FAIRLY LOW AMPLITUDE WITH A WEAK SIGNAL IN TOTAL PRECIPITABLE WATER.
HOWEVER...AN ANALYSIS OF THE SAHARAN AIR LAYER SHOWS A CLEARING IN THE WIDESPREAD DUST NEAR THE WAVE AXIS INDICATING ITS PRESENCE. THE SURFACE LOW IS EMBEDDED WITHIN THE MONSOON TROUGH AND HAS BEEN FOR THE PAST SEVERAL DAYS. MODEL GUIDANCE INDICATES THAT THE LOW WILL PERSIST FOR THE NEXT FEW DAYS AND THE SYSTEM WILL BE MONITORED FOR POSSIBLE DEVELOPMENT.
CURRENTLY...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LIMITED TO THE MONSOON TROUGH REGION FROM 6N-10N BETWEEN 35W-41W.

Good to know we're not the only ones watching this one.


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Quoting Grothar:


Yep, I was watching it melt.


Well, thanks.
I'm sure it is quite a beautiful postcard, and it undoubtedly has a witty and poignant inscription.

My wife and I (will) absolutely love it!

Yer da best kiddo...
Member Since: Posts: Comments:
Just finished making my forecast. This is the second time I've created forecast (Emilia was first), but first time with the keys. Hope y'all like it! As for the forecast, I've created narrow cone because it's gonna stay going west/northwest most of the time until around HR 96. From there, the cone get wider. I really think 99L will be a slow organizing storm so I stick with the tropical storm forecast 120 hours from now. I didn't forecasts any farther than 120 hours because things changes pretty quickly. I do think this storm will go over the eastern edge of Hispaniola as a 70 mph tropical storm and weaken to 60 mph tropical storm before regaining strength to low Category 1 toward SE USA, but things changes pretty fast in the tropics. Again, this is not OFFICIAL FORECAST.

Member Since: August 1, 2011 Posts: 28 Comments: 8007
1406. JLPR2
Quoting JrWeathermanFL:
We go without a storm in july
A. Yes. 99L wont form tomorrow
B. No. We get a TD tomorrow


I'll go with B.
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Quoting JrWeathermanFL:
We go without a storm in july
A. Yes. 99L wont form tomorrow
B. No. We get a TD tomorrow


A yes but not official. The NHC will wait till Aug 1 to classify it. The're usually a day late
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Quoting zillaTX:


I stayed away from the blog due to all the non weather related nonsense. I come back tonight and there it is. Meh!



Hey don't quote my comment I wasn't the one who started it. :( I hate being off the mark but it's a passionate topic to me, any other OT subject I wouldn't have spoke up.
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is it time for another party in tropics chat?
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Quoting wxgeek723:


You're not getting my point. To call them views or thoughts is a misnomer.


I am not trying to sound rude, but what is your point. I am sure that I don't understand what you are trying to convey. I am sure that this blog is not the appropriate place to carry on, but please message me and I would love to carry on this conversation in a respectable manner.
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1401. Grothar
Quoting mikatnight:


No, I absolutely did not get it or you'd have heard from me!

Who can I blame for this outrageous sling of fortune!!!???

(It wasn't the melty one, was it?)


Yep, I was watching it melt.
Member Since: July 17, 2009 Posts: 71 Comments: 26118
We go without a storm in july
A. Yes. 99L wont form tomorrow
B. No. We get a TD tomorrow
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1399. ncstorm
Spathy, TW13..well said!
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Where do you all think 99L will stand tomorrow morning at 0500 in regards to percentage of forming? I think it should at least be orange.
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1397. zillaTX
Quoting wxgeek723:


You're not getting my point. To call them views or thoughts is a misnomer.


I stayed away from the blog due to all the non weather related nonsense. I come back tonight and there it is. Meh!

Member Since: Posts: Comments:
Quoting Grothar:


How do? It looks like the parade has passed up by hydrus. Sometimes I don't even know what people are talking about half the time. There are commercials on TV that are selling things for which I have not a clue as to their use or function.


and some for things with whose functionality I am well acquainted....but just do not ever want to think about...
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1395. Grothar
Quoting russm1:



Wow. Watched this when it was aired live. Haven't seen it since. WOW!!!


Sometimes I think we need a little of that old humor on here sometimes.
Member Since: July 17, 2009 Posts: 71 Comments: 26118
Is it too soon to bring up the XTRP (Extrapolated) hurricane model for 99L?


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Quoting Grothar:


YO!!! Look who's still among the living? Did you get the last postcard I sent you from Greenland last month?


No, I absolutely did not get it or you'd have heard from me!

Who can I blame for this outrageous sling of fortune!!!???

(It wasn't the melty one, was it?)
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
My opinion on this whole gay/straight debate over the past few months especially:

Mind your own business and don't tell others how to live their lives.

Back to 99L.
Well said. 99L is looking much better than this morning.
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The HWRF, GFDL, NOGAPS, GFS, CMC, GFS ensembles, CMC ensembles are all showing development.

Only the ECMWF and UKMET are not showing development.
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Even though for the first time in a while there is a good looking system(exclude 98L) and now still some of the talk is off-topic. But I'm not mad, 99L is looking good and should have its chances increased tomorrow. Also the gfs will begin soon.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
Member Since: July 6, 2010 Posts: 113 Comments: 32016
Quoting crzyboutncweather:



OK, views, thoughts , ideas. I believe that each are entitled to their own thoughts, beliefs and views. However does ridiculing one for theirs make yours any better.


You're not getting my point. To call them views or thoughts is a misnomer.
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Well blog is going strange again, hope we could actually talk about the tropics. Oh well. Good Night.
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My opinion on this whole gay/straight debate over the past few months especially:

Mind your own business and don't tell others how to live their lives.

Back to 99L.
Member Since: July 6, 2010 Posts: 113 Comments: 32016
1385. Grothar
Quoting hydrus:
Its a chicken shaped like a fillet...Good evening ancient one...


How do? It looks like the parade has passed up by hydrus. Sometimes I don't even know what people are talking about half the time. There are commercials on TV that are selling things for which I have not a clue as to their use or function.
Member Since: July 17, 2009 Posts: 71 Comments: 26118
Quoting wxgeek723:


LOLOL you did not just call them beliefs.



OK, views, thoughts , ideas. I believe that each are entitled to their own thoughts, beliefs and views. However does ridiculing one for theirs make yours any better.
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Quoting Astrometeor:
Hey everyone. I have now completely recovered from my wisdom teeth surgery last Wednesday. Like a lot of people on here, I am itching for a storm in the Atlantic. (stupid chiggers)

My birthday is coming up and I was thinking about asking my parents for a handheld anemometer. Does anyone have any suggestions on what to buy? Thanks in advance.
Just had a tooth pulled last week so I could get braces:( My b-day is August 12th and I'm also asking for an anemometer for my b-day. As for what one look around on Scientificsales.com, AnythingWeatherStore.com, google.com, and Amazon.com to find what you want.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
1381. Grothar
Quoting CosmicEvents:
It's basically a firm breast, of chicken....placed on hot buns, of wheat.
.
Simple and quite good.


I must lead a sheltered life.
Member Since: July 17, 2009 Posts: 71 Comments: 26118
1380. Grothar
Quoting mikatnight:


It's Chick Filet???

I thought it was Chicks 4 Gays!

So it's not weird nightclub, just a chicken restaurant...


YO!!! Look who's still among the living? Did you get the last postcard I sent you from Greenland last month?
Member Since: July 17, 2009 Posts: 71 Comments: 26118
Quoting MelbourneTom:
The CMC is the only model I see showing any kind of real development.




I wouldn't go as far and say that, if real you mean into a major system then yes, but the GFS has also been showing development into a Tropical Storm.
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1378. russm1
Quoting GeoffreyWPB:





Wow. Watched this when it was aired live. Haven't seen it since. WOW!!!
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Quoting Grothar:
I really don't want to get in the middle of anything, but what is a Chick Filet? I honestly never heard of it.
It's basically a firm breast, of chicken....placed on hot buns, of wheat.
.
Simple and quite good.
Member Since: Posts: Comments:
Quoting Grothar:


Could you imagine the blog?
What blog, most of the eastern 1/3 of the country is gone if all of those storms happen in one year. But whose ever evacuates or is not really affected would be here and the blog would explode.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
Quoting Grothar:
I really don't want to get in the middle of anything, but what is a Chick Filet? I honestly never heard of it.

It is a fast food chain that sells chicken fillet sandwiches as their main item.
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Quoting crzyboutncweather:


I believe that everyone is entitled to their own opinion. Chik fil a is just stating theirs. Why does the gay/lesbian community have to try and push their beliefs upon others? Now on to the weather.


LOLOL you did not just call them beliefs.
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1371. hydrus
Quoting Grothar:


Here is a link for you.

Link
.
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Quoting Grothar:


Here is a link for you.

Link


That's a cool link! It's weird how some years were insanely active and then nothing for a dozen years. Random? or is there a pattern?
Member Since: Posts: Comments:

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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.