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: 1496 - 1446

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

1496. Patrap
Best put a nother case o Fresca on ice, and a Muzzle/Large Hammer for well, u know
Member Since: Posts: Comments:
1495. icmoore
Note to self: Take a speed reading class oh and a typing class in off season!
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
I think the NHC will favor the westward solution but have a large cone of uncertainty.


a bunch of concentric circles getting bigger and bigger with forecast points very close together
Member Since: Posts: Comments:
Quoting weathermanwannabe:
Given the fact that we have a tropical storm now potentially threatening a large portion of the Gulf Coast, and lots of lurkers or first timers may be coming on the Blog for information, it would be appreciated if no one posts any "false" or misleading posts that bear any resemblance to the Official National Hurricane Center products.


1476.
Member Since: March 22, 2012 Posts: 0 Comments: 723
1492. Grothar
Quoting BrickellBreeze:


Thats real helpful.


I thought I would narrow it down a little.
Member Since: Posts: Comments:
Given the fact that we have a tropical storm now potentially threatening a large portion of the Gulf Coast, and lots of lurkers or first timers may be coming on the Blog for information, it would be appreciated if no one posts any "false" or misleading posts that bear any resemblance to the Official National Hurricane Center products.
Member Since: Posts: Comments:
Quoting FLWeatherFreak91:
I'm debating whether or not the big slug of convection is going to continue with its momentum NE into west florida, or if it is going to wrap around the center and just scrape the coast for a couple hours... Any opinions on this west coasters?



I'm expecting much of it to slowly make progress into western Florida, the rain bands aren't just rotating into the area, the whole complex is slowly drifting northeast if you closely examine satellite and long range radar out of Tampa. It may take a while to fully move in and really start soaking us, but once it does it will be around for a while.
Member Since: Posts: Comments:
1488. BA
Quoting TropicalAnalystwx13:
According to GREarth, those two eddies are rotating around a common center in-between.


according to GRE? what does that mean?
Member Since: Posts: Comments:
Quoting Grothar:


Thats real helpful.
Member Since: March 22, 2012 Posts: 0 Comments: 723
Quoting NCHurricane2009:


Error cone is based on a standard they pick...they don't make it larger or smaller in times of uncertainty.

There is a standard radius they use for one..two...three...four...etc days out. They draw that radius for each of their best guess positions....then connect them to make the cone.

The cone may appear fatter or skinnier depending on if the forecast positions are smushed together (for a slow system) or are spread apart (fast moving system)....
That is not true
Member Since: Posts: Comments:
Quoting WxGeekVA:
And here's my revised track. I have favored a west track the whole time, but not too far southwest. I think the NE Texas coast and SW Louisiana are the areas that need to watch out, including Houston. A minimum Cat 1 isn't out of the question, but I think a 70MPH TS is a reasonable peak. I think the flooding after landfall will end up being what Debby gets remembered for.



Again, no offense, but you have it heading NW immedietly when it is clearly stalled out or making a loop. And if it did head west, a ridge would make it go due west into Central or South Texas.
Member Since: March 22, 2012 Posts: 0 Comments: 723
VDM

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 23rd day of the month at 19:27Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 302)
Mission Purpose: Investigate first suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 07
A. Time of Center Fix: 23rd day of the month at 18:37:40Z
B. Center Fix Coordinates: 25°54'N 87°50'W (25.9N 87.8333W)
B. Center Fix Location: 313 miles (503 km) to the SSE (154°) from New Orleans, LA, USA.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 15kts (~ 17.3mph)
E. Location of the Estimated Maximum Surface Wind: 14 nautical miles (16 statute miles) to the ENE (63°) of center fix
F. Maximum Flight Level Wind Inbound: From 165° at 17kts (From the SSE at ~ 19.6mph)
G. Location of Maximum Flight Level Wind Inbound: 73 nautical miles (84 statute miles) to the ENE (65°) of center fix
H. Minimum Sea Level Pressure: 1002mb (29.59 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 24°C (75°F) at a pressure alt. of 340m (1,115ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 24°C (75°F) at a pressure alt. of 338m (1,109ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 24°C (75°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind and Pressure
N. Fix Level: 1,500 feet
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 5 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 17kts (~ 19.6mph) in the northeast quadrant at 18:11:00Z
Maximum Flight Level Wind Outbound: 26kts (~ 29.9mph) in the southwest quadrant at 18:52:00Z
Sea Level Pressure Extrapolation From: Below 1,500 feet
Remarks Section - Additional Remarks...
PEAK SFC WND 32KTS NW QUAD AT 17:08:20Z
Member Since: June 9, 2007 Posts: 4 Comments: 15891
Link

Center appears to have southward drift in this loop.
Member Since: Posts: Comments:
Quoting NCHurricane2009:


Error cone is based on a standard they pick...they don't make it larger or smaller in times of uncertainty.

There is a standard radius they use for one..two...three...four...etc days out. They draw that radius for each of their best guess positions....then connect them to make the cone.

The cone may appear fatter or skinnier depending on if the forecast positions are smushed together (for a slow system) or are spread apart (fast moving system)....



The radius of each circle, and hence the cone, is based on a 66% probability and not a set width.

Which means that the forecast cone means there will be a 66% probability that the storm will be inside that cone, and of course, a 33% probability that the storm will be outside the cone.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
1480. Grothar
Member Since: Posts: Comments:
Northern gulfcoast strike? look at the small weakness over La in the pressure map where debby wants to sneak in before the high builds in.

Member Since: Posts: Comments:
1477. LargoFl
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
325 PM EDT SAT JUN 23 2012

FLZ069-070-075-232015-
COASTAL COLLIER COUNTY FL INLAND COLLIER COUNTY FL MAINLAND MONROE FL
325 PM EDT SAT JUN 23 2012

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SIGNIFICANT WEATHER ADVISORY FOR...
COLLIER COUNTY
NORTHERN MAINLAND MONROE COUNTY

* UNTIL 415 PM EDT

* AT 320 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
A LINE OF THUNDERSTORMS ALONG A LINE EXTENDING FROM 5
MILES NORTH OF NAPLES TO LOOP ROAD EE CENTER...AND MOVING NORTH AT
15 MPH. SOME OF THE STORMS IN THIS LINE ARE SHOWING SOME
ROTATION WHICH COULD PRODUCE FUNNEL CLOUDS AT ANYTIME.

* THE LINE OF STORMS WILL AFFECT...
NAPLES...
COPELAND...
MONROE STATION...
GOLDEN GATE...
OASIS RANGER STATION...
DADE-COLLIER TRAINING AIRPORT...
GOLDEN GATE ESTATES...
AND SURROUNDING COMMUNITIES.

RESIDENTS NEAR THE PATH OF THESE STORMS SHOULD REMAIN ON THE ALERT
FOR ADDITIONAL STATEMENTS AND POSSIBLE WARNINGS.

STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES.

LAT...LON 2632 8167 2642 8167 2643 8156 2636 8127
2625 8127 2626 8090 2566 8089 2582 8137
2585 8140 2586 8144 2611 8181 2633 8185
TIME...MOT...LOC 1922Z 163DEG 13KT 2621 8183 2575 8094

$$
Member Since: August 6, 2011 Posts: 4 Comments: 38500
And here's my revised track. I have favored a west track the whole time, but not too far southwest. I think the NE Texas coast and SW Louisiana are the areas that need to watch out, including Houston. A minimum Cat 1 isn't out of the question, but I think a 70MPH TS is a reasonable peak. I think the flooding after landfall will end up being what Debby gets remembered for.



NOT AN OFFICIAL FORECAST
Member Since: Posts: Comments:
1474. Patrap


Member Since: Posts: Comments:
Flt. Lvl. Wind (30s): From 203° at 35 knots (From the SSW at ~ 40.2 mph)
Member Since: Posts: Comments:
1472. rxse7en
Quoting bigeasystormcaster:
SPECIAL INTERMEDIATE OBSERVATION:

ALTHOUGH IT APPEARS AS THOUGH THE NHC IS GOING TO GO AHEAD AND CALL 96L TS DEBBY, IT IS A VERY POORLY ORGANIZED SYSTEM. IT IS FIGHTING SW WIND SHEAR FROM A STATIONARY ULL IN THE NW GOM RESULTING IN THE CENTER BEING TOTALLY EXPOSED. ALL OF THE THUNDERSTORMS WITH THE SYSTEM ARE WELL EAST OF THE CENTER AND NOT CO-LOCATED WITH THE CENTER LEAVING THIS A VERY WEAK SYSTEM.

FORECAST:

96L IS PRESENTLY MOVING SOUTH AT ABOUT 5 MPH AND IS EXPECTED TO CONTINUE THIS MOTION FOR THE NEXT 6-12 HOURS. AFTER THAT IT WILL BECOME STATIONARY AND/OR MOVE VERY SLOWLY IN AN ERRATIC MANNER. THIS WILL ACTUALLY BENEFIT THE SYSTEM BY MOVING AWAY FROM THE SHEAR ENVIRONMENT IT IS IN NOW ALLOWING SOME STRENGTHENING TO OCCUR. TONIGHT THE SYSTEM MAY OBTAIN TD STRENGTH AND BECOME A TS TOMORROW MORNING. THE SYSTEM IS THEN EXPECTED TO RESUME A SLOW NORTHERLY MOTION APPROACHING THE NORTH-CENTRAL GOM. BY THIS TIME THE STRONG HIGH PRESSURE SYSTEM IN THE SW US WILL BUILD IN OVER THE SOUTHERN US AND BE THE DOMINANT WEATHER FEATURE. THIS WILL RESULT IN A WESTWARD TURN TOWARD THE TEXAS COAST. DIFFICULT TO ESTIMATE HOW CLOSE TO THE NORTH-CENTRAL GULF COAST THE SYSTEM WILL GET. ALSO THE UPPER LEVEL ENVIRONMENT IS EXPECTED TO BE MUCH MORE FAVORABLE IN THIS REGION OF THE GOM ENABLING THE TS TO OBTAIN HURRICANE STRENGTH PRIOR TO LANDFALL EXPECTED TO BE SOMEWHERE ALONG THE TEXAS COAST. THIS WOULD POSSIBLY BE IN THE WEDNESDAY TO THURSDAY TIME FRAME.

NEXT UPDATE WILL BE SUNDAY EVENING AROUND 7:00PM
Huh? Where did you get this? Looks like the old STORMTOP fake posts in all caps that he used to get warned about.
Member Since: Posts: Comments:
Quoting Jedkins01:


It might be, look at Tampa long range radar, there is definitely some sort of center drifting northeast way out of radar range, that is in contrast to the surface low, although this may be a mid level low, with that much heavy convection out there, it would be easy for another surface low to pop much further east and head northeast with all the moisture and energy, it will be very interesting if a second low pops and they both develop and head in different direction, lol, more then likely though if a new low did develop further east it would "beat out" the original low as far as organization due to the focus of moisture and lift in the eastern gulf.


Even at 850 mb moisture transport is ridiculous in the eastern gulf well east of the actual center, which I also find interesting.


I think that is what the GFS has been doing with this.
Member Since: Posts: Comments:
Quoting BrickellBreeze:


Takes 96L NE out over Florida and just south of the Carolina's.

The GFS takes Debby towards the northeast because it develops a second low pressure area off the coast of Georgia which helps amplify the trough across Canada and the Northeast, therefore pulling the system northeastward. None of the other models show this low, so the GFS should be discounted.
Member Since: Posts: Comments:
If I hadn't been observing this storm over the past 5 days and happened to just now look at it on satellite and radar, I would definitely say anything that formed in the vicinity of Debby would move NE.
Member Since: Posts: Comments:
Quoting Jedkins01:


It might be, look at Tampa long range radar, there is definitely some sort of center drifting northeast way out of radar range, that is in contrast to the surface low, although this may be a mid level low, with that much heavy convection out there, it would be easy for another surface low to pop much further east and head northeast with all the moisture and energy, it will be very interesting if a second low pops and they both develop and head in different direction, lol, more then likely though if a new low did develop further east it would "beat out" the original low as far as organization due to the focus of moisture and lift in the eastern gulf.


Even at 850 mb moisture transport is ridiculous in the eastern gulf well east of the actual center, which I also find interesting.


How will the NHC handle this... Very confusing...
Member Since: March 22, 2012 Posts: 0 Comments: 723
Quoting washingaway:
Can't wait to see NHC track on this thing, I expect we will see a large cone of error.


Error cone is based on a standard they pick...they don't make it larger or smaller in times of uncertainty.

There is a standard radius they use for one..two...three...four...etc days out. They draw that radius for each of their best guess positions....then connect them to make the cone.

The cone may appear fatter or skinnier depending on if the forecast positions are smushed together (for a slow system) or are spread apart (fast moving system)....
Member Since: September 15, 2009 Posts: 476 Comments: 3668
1466. Patrap
Quoting BrickellBreeze:


Is that center what the NHC center will designate Debbie?


from the re-number

note the COC


AL 04 2012062318 , BEST, 0, 26.0N, 87.6W, 40, 1001, TS,
Member Since: Posts: Comments:
Relax guys, this is a typical minimum TS configuration.

Wilma: Dvorak T = 3.0:



Rotate it 90 degrees counter clockwise and it's about the same thing.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
Quoting washingaway:
Is it spliting in two?

Link


It might be, look at Tampa long range radar, there is definitely some sort of center drifting northeast way out of radar range, that is in contrast to the surface low, although this may be a mid level low, with that much heavy convection out there, it would be easy for another surface low to pop much further east and head northeast with all the moisture and energy, it will be very interesting if a second low pops and they both develop and head in different direction, lol, more then likely though if a new low did develop further east it would "beat out" the original low as far as organization due to the focus of moisture and lift in the eastern gulf.


Even at 850 mb moisture transport is ridiculous in the eastern gulf well east of the actual center, which I also find interesting.
Member Since: Posts: Comments:
Quoting BrickellBreeze:


What about the GFS?
Disregard the outlier.
Member Since: Posts: Comments:
1460. Patrap
The largest inhibitor for Debby is the S-Sw Shear imparted from the ULL to her West.

Member Since: Posts: Comments:
That is a whole lot of rain!

Member Since: Posts: Comments:
1458. GHOSTY1
Quoting Bluestorm5:
Got to love wishcasters.... Irene only gave me 60 mph winds in North Carolina but it was scary. Tropical storm is to not be messed with.

And Tropical Storm Allison in 2001 that happened around my 8th birthday, was a mess with all the rain, experienced that, then got to see the panic of Houston during Rita, and then see the people not care about Ike because people thought since Rita missed and wasnt all that bad they could stay for Ike and they saw why you dont ignore tropical systems no matter what they are. Sorry I knew you were talking about Tropical Storms but just wanted to add in some hurricanes i had some experience with so people wouldnt say i dont know what its like to have gone through some. :P
Member Since: Posts: Comments:
I'm debating whether or not the big slug of convection is going to continue with its momentum NE into west florida, or if it is going to wrap around the center and just scrape the coast for a couple hours... Any opinions on this west coasters?
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

What about it?


Takes 96L NE out over Florida and just south of the Carolina's.
Member Since: March 22, 2012 Posts: 0 Comments: 723
1455. nigel20
Quoting MAweatherboy1:

Remember, activity should slow down later in the season as El Nino sets in... Early season forecasts of 10-14 storms are still on track.

I'm thinking that as long as the forecasted el nino is not in the moderate to strong range, then we should have at least a slightly above average hurricane season.
Member Since: Posts: Comments:
Quoting Patrap:


Thats just the MEan center spitting out Vortices on the Down stroke or South side.

It will continue to do that until the CoC can sustain a Warm column.


Is that center what the NHC center will designate Debbie?
Member Since: March 22, 2012 Posts: 0 Comments: 723
Quoting BrickellBreeze:


What about the GFS?

What about it?
Member Since: Posts: Comments:
1450. Gorty
This is such a weird TC.
Member Since: Posts: Comments:
We could get a portobello mushroom shaped cone, with the NHC again advising all residents of the Gulf Coast to monitor the progress.
Member Since: Posts: Comments:
1448. Walshy
Don't be such a Debby downer...
Member Since: Posts: Comments:
1447. Patrap
Mobile
NEXRAD Radar

Base Reflectivity 0.50° Elevation
Range 248 NMI

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
I'm thinking a an extremely large cone moving into the Louisiana/Texas border. Peak intensity of 65kts.


What about the GFS?
Member Since: March 22, 2012 Posts: 0 Comments: 723

Viewing: 1496 - 1446

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