Lesser Antilles may see a tropical storm late this week
A concentrated area of intense thunderstorms near 9N 36W, midway between Africa and the Lesser Antilles Islands, has become more organized this morning. NHC has labeled this system Invest 91L, and is giving it a 60% chance of developing into a tropical depression by 8am Tuesday. Wind shear is a moderate 10 - 20 knots, sea surface temperatures are at record highs, and the dust and dry air of the Saharan Air Layer (SAL) are far enough to the north of 91L to potentially allow further development. The main negatives for development are the current phase of the Madden-Julian Oscillation, which favors downward motion over the tropical Atlantic, and the fact that 91L is too close to the Equator to take much advantage of the Earth's spin to get spinning. Last night's ASCAT pass of the region did show a large region of westerly winds south of 91L, indicating that a surface circulation is trying to form. Satellite imagery shows that the intensity and areal extent of 91L's heavy thunderstorms is increasing. However, there are no signs of a surface circulation, and low-level spiral bands and upper-level outflow are not apparent yet.
Forecast for 91L
There is strong model support for 91L developing into a tropical depression. The GFS, ECMWF, NOGAPS, and UKMET models all develop 91L into a tropical depression by Tuesday or Wednesday. A west to west-northwest motion is predicted, and residents of the Lesser Antilles Islands should anticipate the possibility of a tropical storm arriving in the islands as early as Thursday. It is possible that 91L would pass northeast of the islands, as predicted by the UKMET model, and it is too early to speculate on which of the islands is at most risk. As the storm approaches the Lesser Antilles late this week, 91L will encounter a strong upper-level low pressure system centered north of Puerto Rico. This upper-level low will likely bring high levels of wind shear to the waters just north of Puerto Rico and Hispaniola. Thus, if 91L stays to the south, in the Caribbean, it is far more likely to attain hurricane status than if it pushes north of the Caribbean. As always, long range forecasts of this sort are speculative, and it is too early to reliably say what the long-term risks of 91L becoming a hurricane are. The latest intensity forecast from the SHIPS model shows 91L peaking in strength four days from now, then weakening as it encounters the high wind shear area north of Puerto Rico.
Figure 1. Morning satellite image of Invest 91L.
Next update
I'll have an update Monday morning.
Jeff Masters
Reader Comments
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That would still seem to indicate a poorly defined surface circulation, unless the report was to the southwest of the estimated center position.
sometime ya just got to wonder if the consensus they come up with is individual..or a group thought.
Seems things have a decidedly "slow to recognize the obvious" trend this season.
But thats just one guys opine and obs of the overall performance.
So far.
That was at 18z.
Here is the dinger... the way the ridges are set up in that same time frame this system should come extremely close to the Carolina coast before curving which means areas of the eastern Seaboard or Northeast could actually get a landfall.
It is to the southwest
Totally wrong.
Tru Dat
Your Boss is talking to you, DDR......
heheheh
Hey Orc. I'll make a Deal.
Send that Blob to the cleaners, and I will lift my Dry Spell that I put on you.......
Time is of the Essence.
I am unsure of whether these guys think a tropical cyclone can leave the pouch that it formed in and take a different track, or if the pouch remains with the storm.
Thats the Navy site message .
it will clear when the post falls off the current page.
mummble mumble...
Strange you should mention that, my kaspersky anti-virus stopped a Trojan earlier as well. And the only things I had in my tabs were the nhc site and here.
i see other wave what be hid it
Careful, Ho might become an issue, western or eastern or where ever.
a downcaster?
wishcaster
Your pretty safe for now. Did you notice that the rain blob never makes it past that line in the picture... sort of like an invisible shield.
Then again it could be the edge of the SAT coverage... I guess only time will tell :)
Hey I got it too was wondering what was going own in here....
Taco
That led to the Link prompt here too.
Easily when it comes to banner ad threats.
Like last August.
LOL Yeah, I wondered about that line.
Thought it was some sort of Halo Effect or something.
Powerful mojo, man.
Maybe someone tried posting images from the Navy site or something.
That forecast is about 3 days old, from the 2010073000 cycle.
yes but they need to fix that up a little
Looks like 91L is setting up for the races tonight, it's going to be busy tomorrow.
Thats best if one dosent use the membership.
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