African tropical wave 99L slowly organizing

By: Dr. Jeff Masters , 1:26 PM GMT on July 31, 2012

Share this Blog
38
+

A tropical wave (Invest 99L) near 9°N 41°W, halfway between the Lesser Antilles Islands and the coast of Africa, has the potential to develop into a tropical depression later this week as it moves westward at 10 - 15 mph. Visible satellite loops show that the disturbance now has a moderate amount of poorly-organized heavy thunderstorms that continue to slowly increase in intensity and areal coverage. There is no surface circulation, but some counter-clockwise rotation of the large-scale cloud pattern is evident. Water vapor satellite loops show that 99L has a reasonably moist environment. The latest Saharan air layer analysis shows that the dry air from the Sahara lies to the north of 99L and is currently not affecting the storm. 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 through Friday, and ocean temperatures will remain near 28°C, according to the 8 am EDT run of the SHIPS model. However, a band of high wind shear of 20 - 40 knots associated with the subtropical jet stream lies just to the north of 99L, and it would not be a surprise to see 99L experience some higher shear conditions than are currently forecast. The farther north 99L gets, the higher the shear it will experience, and the SHIPS model is predicting shear in the moderate range, 10 - 20 knots, for Saturday - Sunday, as the storm works its way to 15°N. 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. There are some major differences in the predicted forward speed of 99L, with the ECMWF and UKMET models predicting the storm will reach the Lesser Antilles on Friday, and the GFS predicting a later arrival, on Saturday. At 8 am Tuesday, NHC gave 99L a 20% chance of developing into a tropical depression by Thursday morning. I expect the storm will begin having trouble with tendrils of dry air reaching down from the north at times this week, but 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 morning. The long-range fate of 99L next week is uncertain. A track west to west-northwest through the Caribbean, or to the northwest towards the U.S. East Coast are both possible. The storm is less likely to survive if it heads northwest towards the U.S.

Extreme heat in the Central U.S.
The withering heat in America's heartland continued on Monday, with high temperatures of 112° recorded in Winfield, Kansas and Searcy, Arkansas. Little Rock, Arkansas hit 111°, their 3rd hottest temperature ever record, behind the all time record of 114° set just last year on August 3, and the 112° reading of 7/31/1986. Wichita and Coffeyville in Kansas both hit 111° Monday, and in Oklahoma, Enid, Tulsa Jones Airport, and Chandler all topped out at 111°. Carr Creek, Missouri hit 110°, the hottest temperature measured in the state so far this year. Highs temperatures Tuesday and Wednesday in this region could reach 110° again, as the most extreme heat this week will stay focused over Oklahoma and surrounding states.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1571 - 1521

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48Blog Index

Quoting ilovehurricanes13:
wow!! look at the next tropical wave ready to come in the water its big!!

yeah I'm more looking at that low south of CV islands
Member Since: June 13, 2009 Posts: 2 Comments: 9592
Quoting Tropicsweatherpr:


1.56 inches fell in the San Juan NWS office and that is a record for this date. In parts of the island,a bit more fell.


Thanks for the update I just came back TWPR
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting sunlinepr:


1.56 inches fell in the San Juan NWS office and that is a record for this date. In parts of the island,a bit more fell.
Member Since: April 29, 2009 Posts: 75 Comments: 13311
I see two spinning blobs in the East Atlantic, which is the real one?
Member Since: Posts: Comments:
Typhoon Saola and Tropical Storm Damrey in the same image.

Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

How 'bout Hurricane Chuck Norris?


roflmao! Great!
Member Since: Posts: Comments:
Member Since: March 16, 2012 Posts: 123 Comments: 7887
Member Since: Posts: Comments:
Quoting sunlinepr:
Looks like CMC made adjustments, had 99l passing N of PR now it passes S


yep and by the looks of it it may go south further
Member Since: June 13, 2009 Posts: 2 Comments: 9592
Quoting Patrap:
Best to just use a post number on idiocy, as quoting it well, just gives us who have it on ignore a clean view.




Will do.
Member Since: October 9, 2008 Posts: 0 Comments: 8242
Dude, we get it. The ice is melting.

There's storms be needing watchen!
Member Since: Posts: Comments:
Member Since: Posts: Comments:
1557. wxmod
July 31 and open Arctic water from Alaska to Greenland.

Member Since: Posts: Comments:
Looks like CMC made adjustments, had 99l passing N of PR now it passes S

Member Since: Posts: Comments:
...
Member Since: June 13, 2009 Posts: 2 Comments: 9592
Quoting muddertracker:


They forgot: Don't post pictures of chuck norris.

How 'bout Hurricane Chuck Norris?

Member Since: Posts: Comments:
Member Since: Posts: Comments:
I can see this headed toward the north western Gulf coast.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting Skyepony:
Fresh ASCAT


Still not much definition to the circulation.
Member Since: Posts: Comments:
Quoting Patrap:
All the bloggers comparing any entity,invest, Storm to another years ago is well, spinning their wheels as no two Storms rarely, if ever have the same synoptic patterns..even with climatology in play.

Its not how it works.
You got that RIGHT!
Member Since: Posts: Comments:
Quoting flsky:
Due to the high amount of traffic that Dr. Masters' blog receives, a special community standard has been established for the blog. The following list comprises the "Rules of the Road" for Dr. Masters' blog.

Keep it civil. Personal attacks, bickering, flaming, and general trollish behavior will not be tolerated. Disagreements are fine, but keep them civil and short.
Stay on topic.
No monomania.
No hot linking external or copyright images without the image owner's permission.
Do not circumvent a ban. Most bans last 24 hours or less, please accept the ban. If you create a new username to circumvent a ban, you will be blocked from the site completely.
No comments that contain only personal notes such as, "Good Morning!", or "You've got mail, X".
Do not "1st!", "1st post!", or any of the numerical/linguistic derivatives. This is a worthless use of blog space.
No spamming.
No spamming.
Seriously, no spamming. Spamming includes but is not limited to, trying to sell products, trying to solicit traffic for your own blog, trying to solicit traffic for other commercial entities, etc. Do not post links to your own site unless they are directly relevant and even then, use sparingly.

Tips

Do not enter games of oneupmanship with trolls or bloggers you find to be annoying. You will be banned along side them, as your verbal jousts consume the space and time everyone else is sharing. If you come across a troll or another blogger whom you find to be irritating, please use the site reporting tools and your ignore list.


They forgot: Don't post pictures of chuck norris.
Member Since: Posts: Comments:
1547. ncstorm
Quoting KoritheMan:


No it doesn't, and as far as I know it never did. I thought that was NOGAPS.


The GFS and CMC are showing a storm off the SC coast starting tomorrow and riding up both coasts..Im not going back and posting model runs but the CMC had a 1004mb and the 12z GFS had it clearly at warm core..the 18z I dont count as far as reliable when it comes to the GFS..

Good Night Everyone!
Member Since: Posts: Comments:
Quoting wxchaser97:

Thanks, yours is also nice!
Thank you :)
Member Since: Posts: Comments:
1545. Patrap
The Arctic Northwest Passage is now open, very early too.
Member Since: Posts: Comments:
Member Since: March 16, 2012 Posts: 123 Comments: 7887
1543. Skyepony (Mod)
SAOLA~ click pic to loop.
Member Since: Posts: Comments:
1542. wxmod
Arctic inland passage across Canada. MODIS satellite photo today from Arctic Mosaic.

Member Since: Posts: Comments:
Quoting PensacolaDoug:




How do they know!!!!

Global warming, of course! ;^)
Member Since: Posts: Comments:
Quoting Bluestorm5:
Nice!

Thanks, yours is also nice!
Member Since: March 16, 2012 Posts: 123 Comments: 7887
Quoting trHUrrIXC5MMX:
the storm is gone at the end of this run
Thats because Models are not worth a D that far out!!
Member Since: Posts: Comments:
1538. flsky
Due to the high amount of traffic that Dr. Masters' blog receives, a special community standard has been established for the blog. The following list comprises the "Rules of the Road" for Dr. Masters' blog.

Keep it civil. Personal attacks, bickering, flaming, and general trollish behavior will not be tolerated. Disagreements are fine, but keep them civil and short.
Stay on topic.
No monomania.
No hot linking external or copyright images without the image owner's permission.
Do not circumvent a ban. Most bans last 24 hours or less, please accept the ban. If you create a new username to circumvent a ban, you will be blocked from the site completely.
No comments that contain only personal notes such as, "Good Morning!", or "You've got mail, X".
Do not "1st!", "1st post!", or any of the numerical/linguistic derivatives. This is a worthless use of blog space.
No spamming.
No spamming.
Seriously, no spamming. Spamming includes but is not limited to, trying to sell products, trying to solicit traffic for your own blog, trying to solicit traffic for other commercial entities, etc. Do not post links to your own site unless they are directly relevant and even then, use sparingly.

Tips

Do not enter games of oneupmanship with trolls or bloggers you find to be annoying. You will be banned along side them, as your verbal jousts consume the space and time everyone else is sharing. If you come across a troll or another blogger whom you find to be irritating, please use the site reporting tools and your ignore list.
Member Since: Posts: Comments:
Just found another WindSat surface wind display site:

http://www.nrl.navy.mil/WindSat/data/wind/Ascendi ngWindMap.php

see if image will post... Nope nrl site doesn't hot link
Member Since: Posts: Comments:
By the way... just joking. I didn't think anyone would take seriously that storms might somehow align themselves sequentially in alphabetical order.
Member Since: Posts: Comments:
1535. Skyepony (Mod)
There is some doom...SAOLA is pulling it together...
Member Since: Posts: Comments:
1534. Skyepony (Mod)
Fresh ASCAT
Member Since: Posts: Comments:
Quoting wxchaser97:
Nice!
Member Since: Posts: Comments:
1532. Patrap
Best to just use a post number on idiocy, as quoting it well, just gives us who have it on ignore a clean view.




Member Since: Posts: Comments:
Quoting Patrap:
A Hammer will not get you out of a Submerged car,thats why we carry a center punch in our Pockets whenever we cross the 24 Mile Causeway across Lake Pontchartrain.

Spring Loaded Center Punch w/ FETT lanyard Attachment
[FE103]
Price: $38.00




you dont get a second chance most times.




This will cut a seat belt too, but I like your idea to break that window in a hurry. I have taken a hammer to tempered glass and some of it doesn't play nice. There isn't any arguing with a pointy object though is there. Good to have both.
Member Since: Posts: Comments:
Quoting kipperedherring:
It's reassuring to have Stormpetrol here when faced with any type of tropical development. Besides his uncanny accuracy in predicting the tracks and intensities of tropical systems he's very sexy (and he knows it) !
Foolish comments like that are really not needed.
Member Since: October 9, 2008 Posts: 0 Comments: 8242
ASCAT is letting me down. It has not loaded for two days.
Member Since: Posts: Comments:
1527. Patrap
All the bloggers comparing any entity,invest, Storm to another years ago is well, spinning their wheels as no two Storms rarely, if ever have the same synoptic patterns..even with climatology in play.

Its not how it works.
Member Since: Posts: Comments:
Quoting allancalderini:
Looks like 99L is poise to be Ernesto could be near hurricane status when it nears the windward islands btw do the Gfs still develop the storm near NC?

The cold-core one..? Yeah. But not an actual tropical cyclone.

I've started writing my blog, Kori.
Member Since: Posts: Comments:
Member Since: March 16, 2012 Posts: 123 Comments: 7887
the storm is gone at the end of this run
Member Since: Posts: Comments:
Quoting allancalderini:
Looks like 99L is poise to be Ernesto could be near hurricane status when it nears the windward islands btw do the Gfs still develop the storm near NC?


No it doesn't, and as far as I know it never did. I thought that was NOGAPS.
Member Since: Posts: Comments:
1521. Patrap
A Hammer will not get you out of a Submerged car,thats why we carry a center punch in our Pockets whenever we cross the 24 Mile Causeway across Lake Pontchartrain.

Spring Loaded Center Punch w/ FETT lanyard Attachment
[FE103]
Price: $38.00




you dont get a second chance most times.
Member Since: Posts: Comments:

Viewing: 1571 - 1521

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48Blog Index

Top of Page

About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.