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96L Slowly Organizing on its Way to the Lesser Antilles

By: Dr. Jeff Masters, 2:14 PM GMT on August 20, 2014

A tropical wave (96L) located near 11°N 53°W, several hundred miles east of the Lesser Antilles Islands, is headed west-northwestwards at about 10 - 15 mph. Satellite loops on Wednesday morning showed the wave had a broad, elongated surface circulation and a modest amount of heavy thunderstorm activity that was steadily increasing in areal coverage and intensity. Decent upper-level outflow channels were present on the storm's west and south sides. The storm was poorly organized, though, with a clumpy appearance and just a few small low-level spiral bands. An 8:57 pm EDT Tuesday pass from the ASCAT satellite showed top surface winds near 35 mph in a clump of thunderstorms a few hundred miles to the east of center of 96L. Wind shear is moderate, 10 - 20 knots, and water vapor satellite images and the Saharan Air Layer analysis show that while the wave has plenty of dry air to its north to contend with, it has managed to moisten its environment considerably since Monday. Sea Surface Temperatures (SSTs) are near 28°C, which favors development. The outermost thunderstorms of 96L had appeared on Barbados radar by Wednesday morning.


Figure 1. Latest satellite image of 96L.

Forecast for 96L
The wave should continue to organize over the next two days, and pass through the Lesser Antilles Islands Thursday night and Friday morning, bringing heavy rain showers and strong winds--particularly to the southern islands in the chain. The wave will then track west-northwest through the Caribbean a few hundred miles south of Puerto Rico. The 0Z Wednesday runs of our three most reliable models for predicting tropical cyclone genesis, the UKMET, GFS, and European models, had one model, the UKMET, predicting development into a tropical depression south of Puerto Rico. All three models show that on Saturday, 96L will pass over or just south of the island of Hispaniola, whose rugged terrain would likely disrupt the storm. The 8 am EDT Wednesday run of the SHIPS model predicted that wind shear would stay in the moderate range, 10 - 20 knots, for the next five days. With dry air expected to be in the Caribbean, the moderate levels of wind shear would likely be able to drive the dry air into the circulation of 96L, keeping any development slow. In their 8 am EDT Wednesday Tropical Weather Outlook, NHC gave the disturbance 2-day and 5-day development odds of 30% and 50%, respectively. The Hurricane Hunters are on call to investigate the disturbance on Thursday afternoon, if necessary. If 96L does develop, it would likely be similar to Tropical Storm Bertha of early August while in the Caribbean--a disorganized system that struggles against dry air. The most likely day for development into a tropical depression is Friday, when the storm will be south of Puerto Rico.

A second disturbance near 14°N, 46°W, about 1000 miles east of the Lesser Antilles Islands, has a small area of disorganized heavy thunderstorms with some modest rotation. In their 8 am EDT Wednesday Tropical Weather Outlook, NHC gave this disturbance 2-day and 5-day development odds of 10% and 10%, respectively. None of our three reliable models for predicting tropical cyclone genesis predict that this disturbance will develop over the next five days as it heads west-northwest at about 10 mph.

Active in the Eastern Pacific
In the Eastern Pacific, we have Tropical Storm Lowell and Tropical Storm Karina , which are expected to become entangled with each other early next week and die in the cool waters well to the west of Baja Mexico. The models have been consistently predicting that a another named storm (Marie) will form late this week from a tropical wave (Invest 92E) that crossed Central America on Monday and will move parallel to the Mexican coast a few hundred miles offshore. This storm, which NHC is giving 5-day odds of development of 80%, is something residents of the Baja Peninsula should monitor next week, though current model runs show the storm staying well offshore. Ocean temperatures in the waters just west of the Baja Peninsula are unusually warm---30°C (86°F), which is about 3°C (5°F) above average--so Marie will have plenty of heat energy available to power it. Satellite images are showing the the disturbance already has a pronounced spin to it and a growing area of heavy thunderstorms.

The Western Pacific remains mercifully quiet, with no new named storms expected to develop over the next five days.

Jeff Masters

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Quoting SLU:

Cancelled

No not at all still on
2502. LargoFl
For a good-looking storm, look further West -- Lowell seems to have gotten his act together nicely.
Quoting 2496. LargoFl:

by this coming sunday..a coldfront is supposed to be coming down into north florida...perhaps this front will keep 96 from going northward and may slide across it westward?.....so many things can happen in the next 5 days..and probably all our current opinions will be wrong huh..mother nature is going to do what she wants..regardless of model runs lol.



cold fronts pull tropical systems N and NE ahead of them.
At this point I would have to say this looks like the classic E. Conus Trough will come down far enough and at the proper time to steer 96-L OTS. Recon will be good for the models this afternoon...
Quoting 2464. washingtonian115:

Okay Monster Trough.We'll see if 96L get's kicked out to sea just like the rest of 'em.


It is looking like it might. Spaghetti models are now becoming more favorable towards that track when compared to yesterday's.

Quoting 2493. Naga5000:



Yeah, I stopped in to check the model runs. The local mets in Orlando just started talking about 96L's possible future towards Florida this morning, complete with arrow graphics and red swirly hurricane symbols, so you know it must be "serious business".
I'm hope they're not showing the model run that will attract the most viewers.The HRWF.
2508. ncstorm
06 GFDL Ensembles have come back west



00z
Today's flight

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (APPROACHING LESSER ANTILLES)
FLIGHT ONE -- TEAL 75
A. 21/1730Z
B. AFXXX 01EEA INVEST
C. 21/1515Z
D. 15.0N 57.5W
E. 21/1715Z TO 21/2200Z
F. SFC TO 10,000 FT
2510. GetReal


Again not much structure currently visible with 96L.
Here's the trough on the NAM. Big cut off low just off NC.

Invest looks good, starting to take that nice pinwheel shape. Looks like a Westerly motion right now. I think we'll see a named storm by tomorrow. Nice to have something to track regardless of where it ends up!
Quoting 2499. nrtiwlnvragn:



Link that shows cancellation?
Change for the 22 I believe.
Quoting 2451. GetReal:



96L is lacking in any bone structure, in other words it is currently a classic blob going more towards the west for the time being. IMO.


At this moment, it is. But my gut feeling is that everything will fall into place at once and Cristobal will be off to the races.
JeffMasters has created a new entry.
Quoting 2496. LargoFl:
by this coming sunday..a coldfront is supposed to be coming down into north florida...perhaps this front will keep 96 from going northward and may slide across it westward?.....so many things can happen in the next 5 days..and probably all our current opinions will be wrong huh..mother nature is going to do what she wants..regardless of model runs lol.


Naa, this thing is OTS. A very odd setup this weekend in the southeast. A rare late summer "back-door" cold front is going to be responsible for the weakness that will provide an escape for 96-L. This is the reason for the sharp north to northeast steering that is going to occur. This is not a traditional west to east moving trough that usually recurves these CV systems.
2517. SLU
Quoting 2501. wunderkidcayman:


No not at all still on
Quoting 2499. nrtiwlnvragn:



Link that shows cancellation?


My bad. But I doubt they will find anything more than a large trough with a few spots of 30kt winds in the scattered bands well north of the center.

Yesterday even Cantore thought the system would either go west towards Texas or make the turn and affect the Eastcoast/Fl.

Out to sea wasn't really an option because the high was supposed to build back in and keep the system from going OTS.
Quoting 2507. washingtonian115:

I'm hope they're not showing the model run that will attract the most viewers.The HRWF.


You know they are, lol.
2520. LargoFl
Quoting 2513. allancalderini:

Change for the 22 I believe.


What I posted was plan for tomorrow, not today. Numbering of missions on tomorrow's plan indicate today's missions still fly:

0304A third flight into storm 04 in the Atlantic
0404A fourth flight into storm 04 in the Atlantic
invest 96L moving faster to that will let the trough pick up invest 96L AND go out to sea
The pressures are also low down near 14.2N and 59.5 W on the sw part of the axis.
I just heard the female meteorologist (or broadcaster) on TWC say and I paraphrase because I can't remember every word perfectly,

will it or won't it become a hurricane on its way to the Gulf of Mexico

Who told her to say that?
Quoting 2524. moonlightcowboy:

Good morning, weathergeeks! :) Did Doc go on vacation? Otherwise, little worries. 96L is an open wave, and seems to be increasing fwd speed with little to moderate convection. There is dry air, and if it weren't for the anti-cyclone overhead, we'd probably have little concern.

Have a good day, all! :) Play nice. Hold the fort down and keep the gates closed!


MLC: Long time no see, great to see ya.. I think it's gonna go out to sea and nothing to worry about. It can't gets it act together.

sheri
Has the blog crashed or something.
Something is ill in the atlantic, dry stable air has been killing all in the tropics is impossible for any disturbance gets his act together until reach 70-75 west , since 2011 we are seeing this over and over again.... if this pattern continues this will be a repeat history...

Hurricane Igor (2010) is gaining in strenght in the Atlantic Ocean
For the prospect of a FL landfall, let's just see if 96L can:
A. develop at all
B. survive the Greater Antilles (esp Hispaniola) as more than a wave/depression
C. redevelop to any substantial degree after that between the islands and FL
D. not get turned north by a trough/weakness in the ridge, bearing in mind that most storms DO
turn north before FL (I must have seen it nearly 100 times in my 19 years of storm tracking).
E. if the storm manages to go just north of the Greater Antilles and thus stay/get stronger, the
odds of it affecting FL go down even more by quite a bit.
-It is already obvious this one is not going south of the Greater Antilles (a Charley path).

Atlantic hurricanes can and do hit Florida, but the evidence to me so far overall suggests yet another recurve. zzzzzzzzz Though I am waiting to see 2-3 model runs after data from the aircraft comes in.
Quoting 2529. HurrMichaelOrl:

For the prospect of a FL landfall, let's just see if 96L can:
A. develop at all
B. survive the Greater Antilles (esp Hispaniola) as more than a wave/depression
C. redevelop to any substantial degree after that between the islands and FL
D. not get turned north by a trough/weakness in the ridge, bearing in mind that most storms DO
turn north before FL (I must have seen it nearly 100 times in my 19 years of storm tracking).
E. if the storm manages to go just north of the Greater Antilles and thus stay/get stronger, the
odds of it affecting FL go down even more by quite a bit.
-It is already obvious this one is not going south of the Greater Antilles (a Charley path).

Atlantic hurricanes can and do hit Florida, but the evidence to me so far overall suggests yet another recurve. zzzzzzzzz Though I am waiting to see 2-3 model runs after data from the aircraft comes in.


Please explain to me how it's obvious this isnt going south of the Greater Antilles.
2531. MahFL
Quoting 2484. SLU:


Cancelled


HH is airborne.
dfwstormwatch, I should not have used the word obvious, I should have said unlikely based on both the current trajectory and latest computer model runs. The coc may pass south of a few of the most NE Virgin Islands. The storm may even move over PR. I was, however, referring to a track south of PR, DR/Haiti and Cuba, which is unlikely at this point (but not impossible).
2533. hydrus
Quoting 2486. LargoFl:

Gem-GFS and now this model...all have said this spot gets hit at some point...why?..........
Morning Largo. That actually is a real possibility. In short, it is all timing , and conditions could be good, or even spectacular for development.
2534. hydrus
If one looks closely at the last frame. you can see 96 is indeed becoming better organized. Now further away from the ITCZ and feeling the centripetal affects of the Earth,s rotation, and a possible anticyclone to help it breathe, we will soon have a named system..jmo.

Jacksonville, FL. Usually watch them skirt by.
Hopefully by this time tomorrow, we'll have much more agreement among the models.
It looks like the COC is over the Dominican Republic. I wonder if this ill be able to survive those mountain ranges and if it does I wonder if it will drift further west towards the GOMEX