Gulf of Mexico disturbance 96L close to tropical storm status

By: Dr. Jeff Masters , 1:26 PM GMT on June 23, 2012

Share this Blog
32
+

An area of low pressure and heavy thunderstorms in the Central Gulf of Mexico (96L) is close to tropical depression or tropical storm status, and all interests along the Gulf of Mexico coast should pay attention to the progress of this disturbance. The disturbance has brought heavy rains to Western Cuba, South Florida, and Mexico's Yucatan Peninsula over the past two days, but the disturbance's heaviest rains are located well offshore over the Eastern Gulf of Mexico, where heavy thunderstorms are generating winds near tropical storm-force. A buoy 243 miles east of Naples, FL measured sustained winds of 31 mph, gusting to 38 mph, with 10-foot waves, at 8 am EDT Saturday morning. Our wundermap for the surrounding ocean areas shows a large region of the northern and eastern Gulf of Mexico is experiencing winds of 20 - 30 mph. Satellite-based surface wind measurements taken at 7:22 am EDT Saturday from the newly-available Oceansat-2 scatterometer, courtesy of India, showed a broad, elongated surface circulation over the Central Gulf of Mexico that was not well defined. The satellite saw top surface winds of 30 - 40 mph over the Eastern Gulf of Mexico. Visible satellite loops show that the circulation of 96L has become more defined this morning, and the heavy thunderstorm activity is slowly expanding and growing more intense. Upper-level winds out of the west are creating a moderate 10 - 20 knots of wind shear over the region. Water vapor satellite loops show a modest region of dry air over the Central Gulf of Mexico, which is interfering with development and keeping the western side of 96L's circulation free of heavy thunderstorms. Ocean temperatures are about 28.5°C (83°F) in the Central Gulf of Mexico, which is about 1°F above average. A hurricane hunter mission is scheduled to investigate 96L this afternoon to see if a tropical depression or tropical storm has formed.


Figure 1. Saturday morning satellite image of tropical disturbance 96L in the Gulf of Mexico.


Figure 2. Radar-estimated precipitation for South Florida from tropical disturbance 96L.

Forecast for 96L
Wind shear is predicted to remain in the moderate range through Sunday night, which is likely low enough to allow 96L to develop into a tropical depression or tropical storm by Sunday; NHC gave 96L a 90% chance of developing into a tropical depression by Monday morning, in their 8am EDT Tropical Weather Outlook. The future path of 96L is still unclear. The disturbance will drift slowly northwards through Sunday night, which will likely bring heavy rains of 2 - 4 inches to the Gulf Coast from Central Louisiana to Central Florida. A storm surge of 1 - 3 feet is also likely along the Southeast Louisiana coast on Sunday; coastal flood advisories have already been posted there. By Monday, the majority of the reliable models, including the ECMWF, NOGAPS, HWRF, and UKMET, agree that a ridge of high pressure will build in over the Southern U.S., forcing 96L westwards across the Gulf of Mexico and into South Texas by Wednesday. However, the GFS model, which has been our 2nd most reliable track model over the past two years (behind the ECMWF), has consistently been predicting that a trough of low pressure pushing off of the U.S. East Coast will be capable of grabbing the disturbance and accelerating it to the northeast across Florida north of Tampa Bay on Monday. The GFDL model splits the difference between these extremes, taking 96L northwards to a landfall near the Alabama/Florida border on Tuesday. Given that the majority of the models predict a westward track to Texas, that should be viewed as the most probable path for 96L, but this is a low-confidence forecast. None of the models is predicting 96L will become a hurricane, and the SHIPS model is predicting just a 4% chance of rapid intensification for 96L. Given the moderate levels of wind shear and dry air over the Gulf, only slow to modest intensification of 96L is likely over the next few days.

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: 346 - 296

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 | 40Blog Index

Shear tendency reveals shear is decreasing to the west of 96L.
Member Since: July 8, 2005 Posts: 259 Comments: 23626
Quoting hurricanehunter27:
Making sure that your not trying to make a point of wind shear based on there is no convection. Kind of sounds like that with your wording.
Well convection is 1 sided because of dry air and shear i think.
Member Since: Posts: Comments:
Quoting shawn26:
I do not think thi sis moving west at all. It may appear that way with all of the storms being pushed the the east.
Nope. It's definitely moving SW atm. Use visible satellite and watch the little swirl go go go
Member Since: December 1, 2006 Posts: 2 Comments: 3619
Quoting plywoodstatenative:


If people noticed earlier in the week, there was a trough over the Texas region, that is a blocking notion in itself and if it picked up whatever this storm is to become, would only further to shove it off to the East. For those talking about the other models, figure on this: what time and on what did those models intialize on originally.


This.
Member Since: Posts: Comments:
Quoting hurricanehunter27:
This new convection is over the center right? 96L is now firing on all cylinders.


In that frame, the center is naked at about 25.8N and 87.8W.


We should see convection start firing early afternoon.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
Wind shear tendency...

Member Since: Posts: Comments:
Quoting CaneHunter031472:


Models will be more accurate once it develops into a depression or storm. Models usually have a hard time dealing with smaller or weaker systems.

And often time the first model runs on a system are the most accurate
Member Since: August 14, 2010 Posts: 0 Comments: 183
Quoting sunlinepr:


What's the shear forecast?
15 to 20 knots with the upper low to its west.
Member Since: Posts: Comments:
here are my thoughts on the whole split model thing. that llc is gonna head west today...and another llc will develop under the convection and eventually head east like gfs says. obviously this storm is not gonna be too strong. but given the number of L's the models have been spitting out over the past few days, I think that the stacking in the atmosphere has never really gotten a chance to happen and what you get is the wide divergence on model tracks. i think the convection is too strong to have a typical die off when a llc veers off thus this really interesting possible Debby. just my 2 cents. thanks for the fun blog!
Member Since: Posts: Comments:
Quoting emguy:


GFS does continue to do well with this. It only makes sense though...this model has been consistently locked into a pholosophy way longer than the other models. Interesting notes would be that 96L may be a smidge ahead on schedule in gaining lattitude. Otherwise...Another very interesting note would be that at this general latitude...the GFS saw a wsw-ene egg shaped low with lowest pressures and deepest convection on the eastern side...Now...look at the satellite and 3 words come to mind...dead on target. Later on, this will shead some of that oblong mess on the west side as she tightens up further.


Have you notice that the LLC on the surface maps is moving west away from the main convection. I believe a new LLC will develop or in the process of developing around 25.5N/86.5W and moving North < 5mph.
Member Since: Posts: Comments:
Ok, I'm looking at the newest frame of water vapor, and it appears that the ULL is moving SW, which should tend to push the shear away from the Invest/Storm over the next day or so.

If the ULL holds that motion it would suggest tomorrow or the next day would be much more favorable for the west side of the storm to build convection. Then the storm will have a chance to come in north of the ULL, and have probably at least 3 of the 4 quadrants with heavy convection.

I guess intensity will just depend on how far away the ULL can move before the storm moves through that area.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
These are feisty little storms
Member Since: December 1, 2006 Posts: 2 Comments: 3619
Quoting sunlinepr:
GFS keeps spliting 96L.... Is the shear going to blow some of that convection to the Atl?


Shear should be in the low category by then, so no. It's just the GFS being unrealistic.

That low is the reason it keeps dragging 96L to Florida. The moment it doesn't show that second low anymore, is the second the model will shift to Texas.
Member Since: Posts: Comments:
Quoting Gearsts:
And your point is?
Making sure that your not trying to make a point of wind shear based on there is no convection. Kind of sounds like that with your wording.
Member Since: Posts: Comments:
GFS keeps spliting 96L.... Is the shear going to blow some of that convection to the Atl?

Member Since: Posts: Comments:
Quoting emguy:


Up into last night...this was the case...but the days of belching out swirls and gyres are officially over for 96L now. She really pulled it in this early AM. The winds surge into the Northeast Gulf hurt her earlier...helped her now...when it comes to what we have now...it's on.


What coordinates are you placing the LLC that it's under convection?
Member Since: Posts: Comments:
Quoting hurricanehunter27:
A easy way to see if shear is occuring is by look to see if the lower could tops are moving a different direction then higher ones on the RGB.
And your point is?
Member Since: Posts: Comments:
Quoting Gearsts:
96l naked means that shear is stronger than expected.


What's the shear forecast?
Member Since: Posts: Comments:

Joe Bastardi changing his thinking this morning...now saying system will take a more westward track and miss the trough. He's got the COC at 26 N 87.5 W
Member Since: Posts: Comments:
its struggling but it looks to me like convection MAY BE trying to start wrapping around the center.
Member Since: Posts: Comments:
Quoting Gearsts:
96l naked means that shear is stronger than expected.



Two centers, naked one will head west and dissipate IMO
Member Since: Posts: Comments:
Member Since: September 3, 2011 Posts: 13 Comments: 3468
Quoting Gearsts:
96l naked means that shear is stronger than expected.
A easy way to see if shear is occurring is by look to see if the lower could tops are moving a different direction then higher ones on the RGB.
Member Since: Posts: Comments:
Quoting FSUCOOPman:


Same as it ever it was... convection on the east looks healthier, probably due to Dmax helping this am, but I think we may still have to watch these LLCs getting spit out and reforming.

Still not going to believe ANY model until one can stay within the convection.


Well everyone along the Gulf should be grateful up to now that this system has been fighting with itself over the last 4 days. Whatever decides to come from this I would think we be relatively weak, still could produced catastrophic flooding, but at least we are not dealing with a vertically stacked system over the Gulf Loop current just putting around.

Member Since: Posts: Comments:
12z GFS starts soon, we'll see if it finally flips or sticks to its guns...
Member Since: Posts: Comments:
Hey, all! Jumping on the bandwagon here to see what's going on with 96L. Where is this supposed to go?
Member Since: Posts: Comments:
Recon is still GO for wheels up at 12:15pm EDT (1615z)

Tomorrow recon will be wheels up at 7:15am EDT.
Member Since: July 8, 2005 Posts: 259 Comments: 23626
Quoting BrickellBreeze:


If people noticed earlier in the week, there was a trough over the Texas region, that is a blocking notion in itself and if it picked up whatever this storm is to become, would only further to shove it off to the East. For those talking about the other models, figure on this: what time and on what did those models intialize on originally.
Member Since: Posts: Comments:
Quoting plywoodstatenative:
All of us in South Florida are closely watching this system. Previous of it forming we have been getting slammed with rain for the past few weeks. Anything else would be flood potential. SO if a storm were to form and head this way, worst case is that South Florida becomes a flood zone. Best case is that it heads to Texas where rain is much needed.
Before Tropical Season is over most Floridians may be sick of rain?
Member Since: Posts: Comments:
96l naked means that shear is stronger than expected.
Member Since: Posts: Comments:
I do not think thi sis moving west at all. It may appear that way with all of the storms being pushed the the east.
Member Since: Posts: Comments:


IMO the center is currently is due north of the "I" invest symbol, slowly moving north. I expect this motion to continue to near 28N where I believe 96L will stall for a bit, before resuming a motion generally towrds the west. I'm betting that this system will eventually come ashore in Sw La or Se Texas.
Member Since: Posts: Comments:
HPC Discussion

DESPITE THE AGREEMENT AMONG DETERMINISTIC MODELS AND ENSEMBLE
MEANS...INDIVIDUAL ENSEMBLE MEMBERS OF THE GEFS/ECMWF/CMC STILL
INDICATE A LARGE AMOUNT OF SPREAD WITH THE FLATTENING OF FLOW OVER
THE NORTHERN CONUS LATE IN THE FORECAST PERIOD AND WITH THE
DEVELOPING AREA OF LOW PRESSURE IN THE GULF.
FOR NOW...THE
FORECAST RELIES ON THE CONSISTENCY OF THE ECMWF/ECMWF ENSEMBLE
MEAN. THIS SOLUTION BEST REPRESENTS MODEL CONSENSUS...BUT GIVEN
THE LARGE AMOUNT OF ENSEMBLE SPREAD AFTER DAY 4...MORE WEIGHT WAS
GIVEN TOWARDS THE ECMWF MEAN LATE IN THE FORECAST PERIOD. THIS
REMAINS A LOW CONFIDENCES FORECAST...ESPECIALLY AFTER DAY 4.
MAJOR CHANGES IN THE GULF WILL NOT BE MADE UNTIL AFTER THE 17Z
NHC/HPC COORDINATION CALL.


JAMES/GERHARDT
Member Since: Posts: Comments:
To me the GFS hit the nail on the head showing 2lows
Member Since: Posts: Comments:
My in-laws are heading down to FL on Tuesday.

They are trying to figure out if it does go to FL, will it be out of there by Tuesday night?
Member Since: Posts: Comments:
This new convection is over the center right? 96L is now firing on all cylinders.
Member Since: Posts: Comments:
307. emguy
Quoting FSUCOOPman:


Same as it ever it was... convection on the east looks healthier, probably due to Dmax helping this am, but I think we may still have to watch these LLCs getting spit out and reforming.

Still not going to believe ANY model until one can stay within the convection.


Up into last night...this was the case...but the days of belching out swirls and gyres are officially over for 96L now. She really pulled it in this early AM. The winds surge into the Northeast Gulf hurt her earlier...helped her now...when it comes to what we have now...it's on.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
96L is being sheared some right now, but conditions should continue to improve for it as an upper-level anticyclone develops across the east Gulf and expands. This won't be an asymmetric tropical storm forever..


They are saying if it moves slow enough it could remain under the anticyclone all the way to were ever it landfalls at.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
96L is being sheared some right now, but conditions should continue to improve for it as an upper-level anticyclone develops across the east Gulf and expands. This won't be an asymmetric tropical storm forever..


The longer it remain over water the more true your statement will be.
Member Since: Posts: Comments:
Quoting emguy:


GFS does continue to do well with this. It only makes sense though...this model has been consistently locked into a pholosophy way longer than the other models. Interesting notes would be that 96L may be a smidge ahead on schedule in gaining lattitude. Otherwise...Another very interesting note would be that at this general latitude...the GFS saw a wsw-ene egg shaped low with lowest pressures and deepest convection on the eastern side...Now...look at the satellite and 3 words come to mind...dead on target. Later on, this will shead some of that oblong mess on the west side as she tightens up further.


The GFS looks like it will verify, sorry Texas peeps, it looks like she ain't coming. You couldve used the rain.
Member Since: Posts: Comments:
Quoting seriousman1:


congrats to LEVI he has had this right from day 1...the NHC could really use a guy like him...LEVI the man...


What was Levi's scenario???
Member Since: Posts: Comments:
Quoting FSUCOOPman:


Same as it ever it was... convection on the east looks healthier, probably due to Dmax helping this am, but I think we may still have to watch these LLCs getting spit out and reforming.

Still not going to believe ANY model until one can stay within the convection.


Models will be more accurate once it develops into a depression or storm. Models usually have a hard time dealing with smaller or weaker systems.
Member Since: Posts: Comments:
96L is being sheared some right now, but conditions should continue to improve for it as an upper-level anticyclone develops across the east Gulf and expands. This won't be an asymmetric tropical storm forever..
Member Since: Posts: Comments:
Quoting emguy:
It's unfornate that a lot of folks were not able to see this as it unfolded last night. A wind surge moved up into the NE quadrant of the gulf...Several "gyres" popped out along the way, but it was clear with that wind surge that things would get going further north. The system has worked off all of those gyres and the low is just underneath the western edge of the convection. At this point...the system is north of where the models called...well to the east as well. Ahead of schedule for sure, but will likely slowdown a bit now. As it was, I figured this was an eastern gulf event as eastern gulf systems stay in the eastern gulf in June. As before, I still believe the GFS had a bite on it although not clear cut in it's solution...and now that things are where they are, the door on the westward models has likely been slammed shut. This is a North Florida in June type tropical storm that will likely cross the shore beween Tampa and Apalachicola.
Member Since: Posts: Comments:
299. jpsb
Quoting weatherlover94:
UKMET showing Galveston Texas as a landfall location

Great /s .... Well the good news is that models/tracking always shifts so its good to be the target early.
Member Since: Posts: Comments:
Link

current Wind sear map
Member Since: Posts: Comments:
Quoting NCHurricane2009:

No...I was quoting your comment to highlight how they were saying rapid intensification is unlikely with upper-level cyclonic flow in the area.

Unforutnately...they are probably right about not getting much rain in your area though. With the upper level cyclonic circulation in the west Gulf...that will keep the heaviest precip to the northeast of the storm's center....sorry for the news...
That is OK South Central Texas is desert like anyway with mainly drought with an occasional flood. LOL. Been here over 40 years but alot of droughts and record heat the past 12 years.
Member Since: Posts: Comments:

Viewing: 346 - 296

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 | 40Blog 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

Mostly Cloudy
76 °F
Mostly Cloudy