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: 846 - 796

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

Getting ready to FINALLY get a healthy round of showers/storms here in North Fort Myers, FL! 96L is a weird bird...
Member Since: Posts: Comments:
845. 900MB
Quoting WxGeekVA:
RAMMB 1km visible loop

Another vorticy is emerging from under the convection.


At around 26N a few degrees east of the naked spin?
Member Since: Posts: Comments:
We probably won't have Debby until tomorrow morning.
Member Since: August 14, 2010 Posts: 10 Comments: 16444
Quoting jpsb:
Yes, very helpfull thanks!


I'll 2nd that. I absolutely love graphics where people circle things.

Just like Levi did.

Agree or disagree with what's drawn, you can at least tell what the person is talking about, clearly.

Another thing I love is when people post a motion graphic and site coordinates of what they're looking at.
Member Since: Posts: Comments:
Quoting WxGeekVA:
RAMMB 1km visible loop

Another vorticy is emerging from under the convection.


exactly what I am seeing too
Member Since: Posts: Comments:
Regardless of convection around the center, they need to call this a TD with 30-35mph winds. It's landlocked, and need folks to start paying attention
Member Since: Posts: Comments:
840. Skyepony (Mod)
Quoting FSUCOOPman:


Odd, I thought for sure we'd see TS winds in the heavy convection.

Kind of like Reed's post a few 100 back.


Haven't got to the heavy convection yet.
Member Since: Posts: Comments:
Note the convection channel on the South Side Popping into the inflow.

Member Since: July 3, 2005 Posts: 421 Comments: 127701
Post 807, see my post #25.
Member Since: Posts: Comments:
One thing that will have to be watched is the amount of and intensity of the convection that will occur tonight. Tropical systems seem to intensify at night especially in the formative stages. I think the convection to the east of the center is keeping surface pressures lower there and if that continues I think the center will track more northward instead of turning westward. I would tend to side with the GFS making landfall along the FL/AL border as a result. If the convection can get wrapped around the center, then I think we could see rapid intensification and perhaps more of a westerly direction.
Member Since: Posts: Comments:
GFDL 12z farther east.
Member Since: Posts: Comments:
Quoting Patrap:
Im going with the Pro's and the CoC tagged.


A embedded lil Dinky swirl isnt not another Center,


In this case, with the vortex that the recon plane flew through moving SSW now, it is clearly not the mean center of the storm. It may be the pressure minimum and an isolated wind eddy, but it is not the center of mean circulation.
Member Since: Posts: Comments:
Does anyone know where to find the live hurricane hunter data in google earth? I have installed the "gebweather.kmz" file. Thanks.
Member Since: Posts: Comments:
Quoting Levi32:
There's the 2nd swirl coming out of the convection to the east, verifying that the other swirl is not the main center but just one of multiple vortices.



It would appear the HH agrees, thats where it is heading now.
Member Since: Posts: Comments:
Member Since: August 6, 2011 Posts: 4 Comments: 37102
Quoting Skyepony:
Recon still hasn't seen anything over 32kts.


It shouldn't, they're in the exposed part of the system.
Member Since: Posts: Comments:
Really heavy rains here now .41" in about 15 minutes and climbing fast.
Member Since: Posts: Comments:
I'm curious to see the winds up to 26.2N and 86.9W I want to see if there is a extention of the circulation to these cords. If so, we will find out in about 20-30 minutes as recon is now locating this area on radar and heading due north to it.
We could have the first vortex rotating around it on its sw side.. or the vortex closer to 88W could be it...we will see soon enough.
Member Since: Posts: Comments:
17:38:30Z 25.533N 87.167W 973.5 mb
(~ 28.75 inHg) 266 meters
(~ 873 feet) 1003.5 mb
(~ 29.63 inHg) - From 224° at 16 knots
(From the SW at ~ 18.4 mph) 23.0°C*
(~ 73.4°F*) 23.0°C*
(~ 73.4°F*) 16 knots
(~ 18.4 mph) 14 knots
(~ 16.1 mph) 2 mm/hr
(~ 0.08 in/hr) 14.0 knots (~ 16.1 mph)
87.5%

Time Coordinates Aircraft
Static Air Pressure Aircraft
Geopotential Height Extrapolated
Surface Pressure D-value Flight Level Wind (30 sec. Avg.) Air Temp. Dew Point Peak (10 sec. Avg.)
Flight Level Wind SFMR
Peak (10s Avg.) Sfc. Wind SFMR
Rain Rate Estimated Surface Wind (30 sec. Avg.)
Using Estimated Reduction Factor Peak Wind at Flight Level to
Est. Surface Reduction Factor

HDOB Observations

Independent Calculations from Tropical Atlantic

At 17:29:00Z (first observation), the observation was 349 miles (561 km) to the S (182°) from Pensacola, FL, USA.
Member Since: July 3, 2005 Posts: 421 Comments: 127701
RAMMB 1km visible loop

Another vorticy is emerging from under the convection.
Member Since: Posts: Comments:
825. jpsb
Quoting WxGeekVA:
I mapped out the low clouds from the recent NASA Hi-res pass, and from what I can tell we have a slightly elongated low with 2 eddies in it that are merging. This should be declared a T.S. after the Hurricane Hunters are done.



BTW do you all like me doing these drawings? I do them because I think it helps everyone understand things a little simpler and easier to understand.
Yes, very helpfull thanks!
Member Since: June 30, 2009 Posts: 0 Comments: 1190
Katrina made direct landfalls on 3 states: FL, LA, and MS. But I'm not really sure that matters, it's effects were far more reaching than just it's landfall location. Almost everyone on the Gulf had some impact from the storm. Granted some worse than others.
Member Since: Posts: Comments:
Im going with the Pro's and the CoC tagged.


A embedded lil Dinky swirl isnt not another Center,
Member Since: July 3, 2005 Posts: 421 Comments: 127701
the greatest wind i see on this map is 34.6 north east corner or 30 knot wind
Member Since: August 27, 2006 Posts: 7 Comments: 589
MississippiWx:

I have google earth installed with the "gebweather.kmz" file, but can't find the Hurricane Hunter data?
Member Since: Posts: Comments:
Quoting Skyepony:
Recon still hasn't seen anything over 32kts.


Odd, I thought for sure we'd see TS winds in the heavy convection.

Kind of like Reed's post a few 100 back.
Member Since: Posts: Comments:
819. Skyepony (Mod)
Quoting AllStar17:


They haven't sampled the eastern side.


That's through a little over 20 mins on the southeast side. They may find it in the NE side but they haven't found TS winds yet.
Member Since: Posts: Comments:
LOL..dats a swirl?

LOL
Member Since: July 3, 2005 Posts: 421 Comments: 127701
Quoting Patrap:
Click on FRONTS and MSLP here.

96L Long Floater - RGB Color Imagery Loop
Thanks!
Member Since: Posts: Comments:
Looks like the main center has taking root, went from a small vort to a larger vort and seems to be the real deal now
Member Since: Posts: Comments:
There's the 2nd swirl coming out of the convection to the east, verifying that the other swirl is not the main center but just one of multiple vortices.

Member Since: Posts: Comments:
Member Since: July 3, 2005 Posts: 421 Comments: 127701
Quoting spathy:


But isnt that what...

Didnt you just?

Oh nevermind!


Hey I almost stopped by on Friday, but was too wiped out after work, you guys getting this rain now too?
Member Since: Posts: Comments:
Quoting msglfcst:


Katrina hit Mississippi.....not Louisiana.


Katrina hit Louisiana. Then re-emerged into the Mississippi Sound... then hit Mississippi.
Member Since: Posts: Comments:
It is ATM, but it may just be rotating within the larger gyre of the low, so there's really no way to tell expect to wait for the satellites to update. If it is a "true" LLC it will rotate back to the East on the succeeding satellite updates.

There is ONLY one Low.

Click Fronts, and MSLP here to see it tagged.

96L Long Floater - RGB Color Imagery Loop
Member Since: July 3, 2005 Posts: 421 Comments: 127701
Heavy downpours here now. Upto .25" inches in about 10 mins..
Member Since: Posts: Comments:
Quoting Skyepony:
Recon still hasn't seen anything over 32kts.


They haven't sampled the eastern side.
Member Since: June 29, 2009 Posts: 13 Comments: 5301
807. StP13
The reference "A buoy 243 miles east of Naples, FL measured sustained winds of 31 mph" seems strange to me. Geographically, that bouy would be in the Atlantic Ocean. However, drilling on the link, it looks like the buoy is in the eastern Gulf of Mexico.

Should this actually read "A buoy in the eastern Gulf of Mexico 243 miles west of Naples, FL..."? It makes quite a difference. Just asking...
Member Since: Posts: Comments:
here is a wind field map for you guys .I am just pasting the link .

http://charthorizon.com/m/hm/map
Member Since: August 27, 2006 Posts: 7 Comments: 589
805. Skyepony (Mod)
Recon still hasn't seen anything over 32kts.
Member Since: Posts: Comments:
803. jpsb
Quoting Stormchaser2007:


77 my first year living on the Texas Coast. Anita was the first hurricane I paid attention to, wind gusts of 200 mph definitely got my attention. I was going to ride Allen out in Seabrook, tx. Thank the good lord Allen did not come into Galveston Bay! I am much wiser now, lol.
Member Since: June 30, 2009 Posts: 0 Comments: 1190
Quoting CarolinaHurricanes87:
Amateur questions:

1) Is the naked swirl aka soon to be Debby really moving towards the SW? I swear it looks that way on the visible...

2) Why would it be moving SW right now? I thought she was supposed to be moving North (for now)... slowly stop, maybe meander around for a while, then make her turn E or W depending how things unfold (the strength of the storm, trough, and ridge)???

Thanks in advance for any replies.


It is ATM, but it may just be rotating within the larger gyre of the low, so there's really no way to tell expect to wait for the satellites to update. If it is a "true" LLC it will rotate back to the East on the succeeding satellite updates.
Member Since: Posts: Comments:
801. Skyepony (Mod)
Quoting CarolinaHurricanes87:
Amateur questions:

1) Is the naked swirl aka soon to be Debby really moving towards the SW? I swear it looks that way on the visible...

2) Why would it be moving SW right now? I thought she was supposed to be moving North (for now)... slowly stop, maybe meander around for a while, then make her turn E or W depending how things unfold (the strength of the storm, trough, and ridge)???

Thanks in advance for any replies.


It's wobbling around pretty hard as the two low circulations came around each other to become one.
Member Since: Posts: Comments:
Quoting Drakoen:
The HWRF 12z still taking 96L westward.



Seems much more realistic to me than going into LA.
Member Since: Posts: Comments:
Quoting msglfcst:


Katrina hit Mississippi.....not Louisiana.


I thought it hit Florida...
Member Since: Posts: Comments:
Quoting WxGeekVA:
I mapped out the low clouds from the recent NASA Hi-res pass, and from what I can tell we have a slightly elongated low with 2 eddies in it that are merging. This should be declared a T.S. after the Hurricane Hunters are done.



BTW do you all like me doing these drawings? I do them because I think it helps everyone understand things a little simpler and easier to understand.
Two Thumbs Up
Member Since: Posts: Comments:
12z UKMET
Member Since: Posts: Comments:

Viewing: 846 - 796

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.