Invest 94L and the Lesser Antilles

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

Share this Blog
1
+

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.


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: 2708 - 2658

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 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Quoting kmanislander:


Hi Pottery

These weak systems are a pain in the you know what. They appear to be going in several different directions at once.

Weak as it is I just don't see what would pull a Twave to the WNW. The low level flow controls the motion.
So the question is not when will it turn, but when will it intensify!
Member Since: August 19, 2008 Posts: 6 Comments: 2490
2707. Relix
StormW ban should have waited. He's a great resource especially now, it was a pretty minor offense compared to other things here.
Member Since: August 3, 2006 Posts: 0 Comments: 2741
2706. pottery
Kman, I think that the fact that it is an Invest, with potential, is making a couple of people think it is a stronger system than it is.
That may change, but for now, it's not much more that a wave, as you say.
Had an inch of rain today. Nice!
Member Since: Posts: Comments:
Quoting duprk452:
That came through here earlier tonight... my poor dog nearly had a panic attack! Poor thing was trembling so bad he couldnt even stand up on his own!


nothing here in New Iberia,,,,,not even a drizzle
Member Since: Posts: Comments:
2704. hydrus
Quoting GeoffreyWPB:
Storm gets banned for a pic...and ? does not for ?. IMO...94 should be declared a depression sometime tomorrow.
Did storm.W.really get a 24 hour ban?
Member Since: September 27, 2007 Posts: 1 Comments: 22617
2702. amd
Quoting hunkerdown:
shear is a result of the anticyclone, not going to affect 94L...plus, you say "keep 94L an open wave", it is not currently an open wave...


you are correct on the second part, a 1007-1009 mb low has been analyzed by the nhc so it is not an open wave.

However, i respectfully disagree on the first statement. Yes, the shear may technically be a part of an anticyclone, but the anticyclone is weak at best, being stretched like a rubber band (using IKE's term from earlier today). This suggests that the digging ULL is eroding that anticyclone, as heavy shear is so close to the center of the anticyclone. This means that there is a chance that the anticyclone weakens to the point that the center becomes affected by the heavy shear. BTW, if 94L tries to form a more concrete LLC further to the north, the shear becomes more intense.

I still believe that shear will keep 94L weak, whether it becomes an open wave is just a matter of semantics that frankly is irrelevant.

BTW, a real anticyclone exist in the upper levels near 15 N 35W. Notice how far any crippling shear is away from that anticyclone.
Member Since: August 29, 2005 Posts: 0 Comments: 1024
2701. Patrap
tornadude just wu-mailed and said he also got a 24 hour Bann for off topic Images

I feel like "Publishers Clearinghouse" for the Banned.


Banned on the Run
Member Since: Posts: Comments:
Shows you how complex weather is...within a few posts...clearly a northern component and another moving due west.

Member Since: Posts: Comments:
Quoting pottery:
Hi Kman.
I agree with you. Not seeing a north component as yet....


Hi Pottery

These weak systems are a pain in the you know what. They appear to be going in several different directions at once.

Weak as it is I just don't see what would pull a Twave to the WNW. The low level flow controls the motion.
Member Since: Posts: Comments:
Currently, its jogging more westward, but it has been in a general WNW motion all day.
Member Since: Posts: Comments:
Quoting Funkadelic:

What!! Stormw gets banned for that, but not weatherstudent for plagirism?


I got banned for 24 hours for an off-topic pic Friday. From now on, I link to my humorous pics.

Member Since: Posts: Comments:
Quoting Patrap:
Geeezum,..just had Pea Sized hail for 45 secs then a wisp of 30 Plus under the wood threshold and that wicked ,Hummmmmmmmmmmmmmmmmmm...


I hate that sound
Member Since: September 5, 2007 Posts: 0 Comments: 3488
2695. Patrap
Quoting atmoaggie:

I am jealous. We got nary a drop out of this frotal passage.


Check out the winds thru the Levels in this Line atmo..

Member Since: Posts: Comments:

Hurricane Wilma at her peak


Hurricane Jimena earlier today

Now I want to say that Wilma was the most impressive storm I have ever seen, and rightfully so with being the most intense pressure reading ever recorded in an Atlantic Basin Hurricane - 882mb, Jimena lowest pressure was 945mb and at 11pm it will be 940mb I believe. So with that said, Jimena's appearance is much more ragged than Hurricane Wilma's and never void of convection in her outflow pattern. Just a tremendous hurricane.
Member Since: Posts: Comments:
Quoting Patrap:
Rock and Rolling T storms along that frontal Boundary Fetch here..

Start the frigging Pumps COE's..



That came through here earlier tonight... my poor dog nearly had a panic attack! Poor thing was trembling so bad he couldnt even stand up on his own!
Member Since: Posts: Comments:
2692. pottery
Hi Kman.
I agree with you. Not seeing a north component as yet....
Member Since: Posts: Comments:
Quoting SavannahStorm:


It's also visibly gaining latitude on the precipitable water imagery.



94L is not vertically stacked. Much of the cloud cover is displaced to the NE of the surface low along with the moisture field but if you all think it is going that way then so be it.
Member Since: Posts: Comments:
Storm gets banned for a pic...and ? does not for ?. IMO...94 should be declared a depression sometime tomorrow.
Member Since: Posts: Comments:
2689. Patrap
Quoting Funkadelic:

What!! Stormw gets banned for that, but not weatherstudent for plagirism?


I have sent a inquiry as to that post by WS,..seems the Table needs balancing for sure.
Member Since: Posts: Comments:
Quoting NOVArules:



It won't hit Virginia! We have an invisible hurricane shield :D


You must shop at the same hurricane shield store as we do down in Georgia.
Member Since: Posts: Comments:
Quoting Patrap:
Rock and Rolling T storms along that frontal Boundary Fetch here..

Start the frigging Pumps COE's..




I am jealous. We got nary a drop out of this frotal passage.
Member Since: Posts: Comments:
2685. Patrap
Geeezum,..just had Pea Sized hail for 45 secs then a wisp of 30 Plus under the wood threshold and that wicked ,Hummmmmmmmmmmmmmmmmmm...

Member Since: Posts: Comments:
Quoting canesrule1:
NEW PERCENTAGES UPDATE!!!!


U.S Eastern Coast: 79%

Out-to-sea: 20%

Caribbean: 1%




It won't hit Virginia! We have an invisible hurricane shield :D
Member Since: Posts: Comments:
Quoting kmanislander:


The models are out to lunch and as for extrap well, short term motions do not a trend make.



It's also visibly gaining latitude on the precipitable water imagery.

Member Since: Posts: Comments:
Quoting Patrap:
As per Senior Chief StormW's wu -mail to me..


StormW has been Banned for 24 Hours for the GEICO Lizard pic,so he and I advise all to belay any off topic Humor Pic for the extended busy week ahead.

As you were Senior Chief StormW says,..He'll be back in 23.45 hrs,or in his Blog till then.

whoa...thanks for the heads up Pat.
Member Since: September 5, 2007 Posts: 0 Comments: 3488
So when does 94L "Go North"?
Member Since: Posts: Comments:
You'all talking bout 94L, did you see what's coming off Africa like that other guy said?
Member Since: Posts: Comments:
2678. Patrap
Rock and Rolling T storms along that frontal Boundary Fetch here..

Start the frigging Pumps COE's..



Member Since: Posts: Comments:
2677. GatorWX
Structure is the most important factor in upgrading to depression. Remember, Bill didn't have much convection when it was upgraded, actually it was quite similar to 94 in appearance.

The area in the GOM is under a tremendous amount of shear, no threat at all! The areas to watch are, at the moment 94L and down the road, African wave!!! Can't wait to see the latter in a couple days! It already looks teriffic.
Member Since: Posts: Comments:
Quoting canesrule1:
Well, the models had it moving WNW, XTRP has it moving WNW, and the satellite itself to the trained eye, has 94L moving WNW, oh and the Dvorak numbers have it moving WNW.


The models are out to lunch and as for extrap well, short term motions do not a trend make.

Member Since: Posts: Comments:
2674. Genex
I'm looking at the satellite images of Jimena. If I read this correctly,it's drawing up moisure from the Gulf onto South Texas from its' center off the Pacific coast. Amazing.
Member Since: Posts: Comments:
IF 94L becomes a TD tomorrow, TS watches should be posted.

See you all in the morning! Have a great night!
Does 94L look like its tighting up????
Member Since: Posts: Comments:
2671. Patrap
Quoting StormFreakyisher:
Pat, why is it that when you post the water vapor loop, it looks like 94L is moving north but visible loop or any others it looks like it is going west.



Good Question.I also use thew Floater RGB Loop to check out motion...check the Lat/Lon Boxes
Member Since: Posts: Comments:
Quoting btwntx08:

sunrise
11PM to about 5AM.
Quoting kmanislander:


That outlook has failed to verify for a long time now. I only pay attention to what is actually happening out there and the fact of the matter is that 94L persistently refuses to go off to the WNW or points further N.
Well, the models had it moving WNW, XTRP has it moving WNW, and the satellite itself to the trained eye, has 94L moving WNW, oh and the Dvorak numbers have it moving WNW.
I'll stick by my opinion that TS watches will be put up for a portion of the Islands sometime tomorrow.
Member Since: Posts: Comments:
2667. JLPR
well im out till 12am tonight
later
Member Since: Posts: Comments:
Quoting KATRINABILOXIGIRL:
I don't know about you but I am definitely keeping my eye on it


Yes indeed....I say anything is possible.
Member Since: Posts: Comments:
Quoting gordydunnot:
Over the years I believe there have been several storms with two eyes, especially when that get that intense. I may be wrong, I am sure I will find out after this post.

Ehh, you might be thinking double eyewall (one inside the other)
Nooooo wayyyy, like I said the first time it got posted.
Member Since: Posts: Comments:
Quoting atmoaggie:

And QuikScat has the ability to show a closed circulation where there is none.

I don't disagree that it probably going to be a TD in the next day. But there is a chance it does nothing. And in this business any chance is a chance to consider.
true
Quoting canesrule1:
True, but the actual outlook has it moving WNW:

"AS IT MOVES WEST-NORTHWESTWARD AT AROUND 15 MPH."


That outlook has failed to verify for a long time now. I only pay attention to what is actually happening out there and the fact of the matter is that 94L persistently refuses to go off to the WNW or points further N.
Member Since: Posts: Comments:
2661. Patrap
As per Senior Chief StormW's wu -mail to me..


StormW has been Banned for 24 Hours for the GEICO Lizard pic,so he and I advise all to belay any off topic Humor Pic for the extended busy week ahead.

As you were Senior Chief StormW says,..He'll be back in 23.45 hrs,or in his Blog till then.
Member Since: Posts: Comments:
Poor Funktop presentation:

2659. will40
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED ABOUT 850 MILES EAST OF THE WINDWARD ISLANDS HAVE
DECREASED DURING THE LAST FEW HOURS. HOWEVER...ENVIRONMENTAL
CONDITIONS STILL APPEAR FAVORABLE FOR DEVELOPMENT...AND THIS SYSTEM
HAS THE POTENTIAL TO BECOME A TROPICAL DEPRESSION DURING THE NEXT
DAY OR SO AS IT MOVES WEST-NORTHWESTWARD AT AROUND 15 MPH. From the 8:00
Member Since: Posts: Comments:
Pat, why is it that when you post the water vapor loop, it looks like 94L is moving north but visible loop or any others it looks like it is going west.
Member Since: Posts: Comments:

Viewing: 2708 - 2658

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 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Top of Page

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.

Local Weather

Overcast
30 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron