Invest 94L and the Lesser Antilles

By: Dr. Jeff Masters , 9:51 AM GMT on August 30, 2009

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Hi, this is Dr. Rob Carver filling in for Dr. Masters. The convection associated with Invest 94L has intensified, prompting the NHC to issue an early Tropical Weather Outlook to update the situation. Essentially, people in the Lesser Antilles need to start paying attention to the seas and skies. Looking at the computer track models, the set of model solutions are fairly similar to the Saturday model runs. A set of dynamical models (GFDL, HWRF, NOGAPS) runs to the NE of the Antilles, while the simpler models (LBAR, BAM family) are more easterly and take 94L over the Antilles. I do not ascribe any significance to the 00Z GFS track following the simpler models over the dynamical models. From my examination of the 00Z GFS run, it looks like the simulated 94L weakens too much, so the automatic vortex tracker picks up another vorticity feature. As for the future of 94L, there is a large area of large wind shear to it's north. It will need to keep it's track at WNW-W for intensification.

Update at 6AM EDT
I would be remiss if I didn't mention the major hurricane in the Eastern Pacific, Jimena At this time, Jimena has a satellite-estimated maximum wind speed of 115 mph, making it a Category 3 storm on the Saffir-Simpson scale. Jimena has an impressive presentation in satellite imagery with a large area of cold anvil cirrus in the center of the storm. The following microwave imagery indicate the formation of a relatively potent central eyewall, which is responsible for intensification.


Fig. 1 SSMI 85 GHz PCT at 0244Z Aug 30. Image courtesy of NRL.


People along the western coast of Mexico and along along the Baja need to pay close attention to this dangerous storm. I emphasize that using the current track and intensity forecast, Jimena will be a Category 4 storm when it approaches the tip of Baja and a Category 3 storm when it makes landfall up the coast.

It is worth noting that if Jimena follows the more easterly tracks presented in the computer track forecasts, the remnants of Jimena could impact NM and western Texas.


I'll update this entry further in response to 94L's development.


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2408. Drakoen
Early 00z runs have shifted to the north
Member Since: October 28, 2006 Posts: 57 Comments: 29714
Yeah it does look similar like yesterday but better circulation and convection is still persistant, unlike yesterday if poofed out.But tnight convection is still here and hasn't poofed out fully yet, therefore DMAX will even help it more if convection holds for another 6-8 hours.
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Quoting JLPR:


it looks identical to yesterday before d-max
but now it has better structure


Quoting GatorWX:
94L looks pretty good this evening, structurally. Convection is pretty spread out with not much if any over center and there is no really heavy convection. The core of the system however, is very intact and given a good diurnal maximum, could very well inch it up to depression status overnight. As soon as it builds and holds moderate to strong convection over or very near its center, it will be classified as a depression.

The storm that still really captures my attention, is the wave over Africa. Been tracking it for six days now. Continues to look quite impressive. The low pressure looks mostly mid-level, but could very well be at the surface too. We'll see tomorrow as it finally departs the coast. The wave has become much more compact than a couple days ago, allowing me to think it may have development a closed low and is concentrating its convection over the center. The wave should have similar conditions as 94L for at least the first 4 days of its existence, which, for the eastern Atlantic, are good. We'll see how it adapts to the aquatic lifestyle by Tuesday. By that time it will have had plenty of time to adjust. Some times waves over Africa that are very well developed structurally have and stay that way for some time have trouble upon first entering the ocean. They usually adjust and come back after a day or two, but sometimes they never fully recover. I imagine this wave here will become an invest almost immediately, within a day or two. All it will need to do most likely is hold on to its convection and close off it llc if it hasn't already done so. Sorry this post is so long.

African wave nearing the coast. Nexsat animated loop.


Good observations!
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2405. Patrap
94L 18 Z Dynamic Model Suite

Member Since: July 3, 2005 Posts: 414 Comments: 125592
Quoting DestinJeff:


1. Copy the image properties address or url address

2. Click the "Image" button above where you type your post.

3. You may get an IE warning, just click thru it.

4. Paste url into window that pops up.

5. Hit enter on keyboard (may have to hit it a few times, then the html code will appear in the text box for your post.

6. Click Post Comment

And if it is something you cannot link in here directly, goto tinypic.com and upload it. You will get a URL there to past into the box here.
Member Since: Posts: Comments:
Quoting watchdog40:
I am so confused, just curious as why the models are all so different? Also what are the experts predictions on where 94 will go?

Thanks.


Here's my tropical update
Member Since: July 24, 2005 Posts: 407 Comments: 19076
thanks for the reply.
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Take a look at the track of Hurricane Edna in 1954:

Link

Wowza! What a strange track. Powerful storm though....
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LOL


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I'd put the ill-defined center around 14N, 48W...
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2398. JRRP
Member Since: August 16, 2007 Posts: 0 Comments: 5081
I am so confused, just curious as why the models are all so different? Also what are the experts predictions on where 94 will go?

Thanks.
Member Since: Posts: Comments:
Quoting StormW:



Haven't seen him!
hey storm how is the steering layer now?
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2395. Dakster
As much as I disagree with 94L going NW, I have to disagree with the DUE WEST statement. If it truly was going due west then it would still be lower than 10N.
Member Since: March 10, 2006 Posts: 0 Comments: 9717
Quoting spathy:
456 Bite your tongue!

"I fogot to buy Global Warming Insurance"

You will give someone ideas


cant image the premiums.

But I'm getting it before 2012
Member Since: July 24, 2005 Posts: 407 Comments: 19076
LOL StormW is here.
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Quoting pcolasky:


A new geico commercial?

Hmm. I know where you got that. Unless you are MW, himself.
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LOL. Hi Storm! Good to see you are here!
Member Since: Posts: Comments:
2390. GatorWX
94L looks pretty good this evening, structurally. Convection is pretty spread out with not much if any over center and there is no really heavy convection. The core of the system however, is very intact and given a good diurnal maximum, could very well inch it up to depression status overnight. As soon as it builds and holds moderate to strong convection over or very near its center, it will be classified as a depression.

The storm that still really captures my attention, is the wave over Africa. Been tracking it for six days now. Continues to look quite impressive. The low pressure looks mostly mid-level, but could very well be at the surface too. We'll see tomorrow as it finally departs the coast. The wave has become much more compact than a couple days ago, allowing me to think it may have development a closed low and is concentrating its convection over the center. The wave should have similar conditions as 94L for at least the first 4 days of its existence, which, for the eastern Atlantic, are good. We'll see how it adapts to the aquatic lifestyle by Tuesday. By that time it will have had plenty of time to adjust. Some times waves over Africa that are very well developed structurally have and stay that way for some time have trouble upon first entering the ocean. They usually adjust and come back after a day or two, but sometimes they never fully recover. I imagine this wave here will become an invest almost immediately, within a day or two. All it will need to do most likely is hold on to its convection and close off it llc if it hasn't already done so. Sorry this post is so long.

African wave nearing the coast. Nexsat animated loop.
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2388. Patrap
Member Since: July 3, 2005 Posts: 414 Comments: 125592
2387. JLPR
Quoting Relix:
Screw you 94L =P


xD
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Quoting Patrap:


Moisture doesn't seem to be an issue for 94L. It has moistened its environment quite well. The issue is that it hasn't established a strong enough low pressure area yet to keep the convection persistent and if I had to guess, the convergence/divergence isn't the best (haven't looked at a map though). Another thing is that the downward pulse of the MJO isn't helping either.
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Quoting atmoaggie:
Goofy in the IR:

That is downright eerie.....

Hope somebody is archiving these loops....
Member Since: October 25, 2005 Posts: 19 Comments: 20725
2381. JLPR
Quoting Patrap:


it looks identical to yesterday before d-max
but now it has better structure
Member Since: Posts: Comments:
Quoting pcolasky:
For those of you with patience, how do I post an image, all I get is url address.


Look up to the right on this page and see link:

How to start your own blog, and add blog images and links


and then click on:

How do I add an image?



Member Since: Posts: Comments:
Is StormW out for the weekend? I haven't seen him post all day. Would love to get his perspective.
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I fogot to buy Global Warming Insurance
Member Since: July 24, 2005 Posts: 407 Comments: 19076
2377. JRRP
Quoting Weather456:
Notice that not even the experts agree on loacation

lol lol

25kts-1007mb-121N-475W
30/2345 UTC 12.4N 48.4W T1.0/1.5 94L -- Atlantic
AL 94 2009083100 BEST 0 126N 483W 25 1007 DB
WITH AN ASSOCIATED 1007 MB SURFACE LOW CENTER NEAR 11N48W.

The most accurate center appears to be:

94L is located somewhere in the Atlantic

lol asi no se vale
Member Since: August 16, 2007 Posts: 0 Comments: 5081
2376. JamesSA
Quoting atmoaggie:
Goofy in the IR:



If you focus on other features such as cloud bands you can see that the entire image is doubled.
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Quoting okieviewer:
long time reader. i see a lot of comments and info on 94L and not near as many on the large hurricane that is now in the pacific. Is the reason for this because the hurricane does not appear to do damage to the US? I am just curious as I am try to follow along and learn.

Well I am pretty sure there are other blogs that deal with the E PAC in spanish or English.This is more of the Atlantic basin blog because Dr. Jeff Masters makes blogs mostly based on the US and Atlantic, therefore we are the Atlantic bloggers.But I have seen many other bloggers on here from Europe and Australia and such and such.
Member Since: Posts: Comments:
Quoting okieviewer:
long time reader. i see a lot of comments and info on 94L and not near as many on the large hurricane that is now in the pacific. Is the reason for this because the hurricane does not appear to do damage to the US? I am just curious as I am try to follow along and learn.


Okie, right or wrong, I think it is because it is lest often that the pacific storms impact the US or Mexico. Fewer people from those areas are on the blogs; therefore fewer posts concerning the very impressive Jimena.

Member Since: August 17, 2005 Posts: 26 Comments: 15472
Quoting atmoaggie:
Goofy in the IR:



A new geico commercial?
Member Since: Posts: Comments:
Quoting oddspeed:
impressive outflow in gom
Produced the first little bit of dampness in 45 days here in Port A. Thanks!!
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Quoting atmoaggie:
Goofy in the IR:



that is so creepy looking
Member Since: July 24, 2005 Posts: 407 Comments: 19076
2370. Patrap
Member Since: July 3, 2005 Posts: 414 Comments: 125592
2369. Drakoen
Quoting nrtiwlnvragn:


12.1 47.5 was the 18Z position, but yes SSD and TAFB almost always have a different position from Dvorak analysis.


Exactly. This is nothing surprising.
Member Since: October 28, 2006 Posts: 57 Comments: 29714


XtremeHurricanes.com

This video was produced in Hi-Definition. As of this time, YouTube has not yet finished processing the video, so although it can be seen, it still cannot be seen in HD.

Wait for it! :)
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Goofy in the IR:

Member Since: Posts: Comments:
Quoting Weather456:
Notice that not even the experts agree on loacation

lol lol

25kts-1007mb-121N-475W
30/2345 UTC 12.4N 48.4W T1.0/1.5 94L -- Atlantic
AL 94 2009083100 BEST 0 126N 483W 25 1007 DB
WITH AN ASSOCIATED 1007 MB SURFACE LOW CENTER NEAR 11N48W.

The most accurate center appears to be:

94L is located somewhere in the Atlantic


12.1 47.5 was the 18Z position, but yes SSD and TAFB almost always have a different position from Dvorak analysis.
Member Since: Posts: Comments:
2365. JLPR
Quoting Weather456:
Notice that not even the experts agree on loacation

lol lol

25kts-1007mb-121N-475W
30/2345 UTC 12.4N 48.4W T1.0/1.5 94L -- Atlantic
AL 94 2009083100 BEST 0 126N 483W 25 1007 DB
WITH AN ASSOCIATED 1007 MB SURFACE LOW CENTER NEAR 11N48W.

The most accurate center appears to be:

94L is located somewhere in the Atlantic


lol xD the confusion =P
Member Since: Posts: Comments:
Quoting Drakoen:


NHC observations based on 18z. Not current.
But they are using 2315 imagery.

This is a weird storm.
Member Since: October 25, 2005 Posts: 19 Comments: 20725
2362. NARCHER
recon in rimena tomorrow

rough ride
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2361. Patrap
Member Since: July 3, 2005 Posts: 414 Comments: 125592
long time reader. i see a lot of comments and info on 94L and not near as many on the large hurricane that is now in the pacific. Is the reason for this because the hurricane does not appear to do damage to the US? I am just curious as I am try to follow along and learn.
Member Since: Posts: Comments:
My wish is to see at least one Fujiwhara Effect in my lifetime.It would be a miracle.
Member Since: Posts: Comments:
Notice that not even the experts agree on loacation

lol lol

25kts-1007mb-121N-475W
30/2345 UTC 12.4N 48.4W T1.0/1.5 94L -- Atlantic
AL 94 2009083100 BEST 0 126N 483W 25 1007 DB
WITH AN ASSOCIATED 1007 MB SURFACE LOW CENTER NEAR 11N48W.

The most accurate center appears to be:

94L is located somewhere in the Atlantic
Member Since: July 24, 2005 Posts: 407 Comments: 19076

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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.