Lesser Antilles Disturbance 97L Still Disorganized

By: Dr. Jeff Masters , 2:34 PM GMT on September 03, 2013

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A tropical wave over the Lesser Antilles Islands (Invest 97L) is moving west-northwest at 10 mph, and is bringing sporadic heavy rain showers to the islands. Top sustained winds observed in the islands as of 10 am AST Tuesday were mostly below 15 mph. Heavy thunderstorm activity has been low since Monday, and is spread out, as seen on satellite loops. The thunderstorms are poorly organized, and there is no sign of a well-organized surface circulation. Martinique radar shows little evidence of rotation to the echoes, and no low-level spiral bands forming. Upper level winds are favorable for development, with wind shear a low 5 - 10 knots, and an upper-level anticyclone overhead. An area of dry air from the Saharan Air Layer (SAL) surrounds 97L and is interfering with development, though the the 12Z Tuesday balloon sounding from Guadeloupe near the center of 97L showed moist air through the entire depth of the atmosphere.


Figure 1. Latest satellite image of Invest 97L.

Forecast for 97L
Wind shear is expected to be low through Friday, and ocean temperatures will be warm, 29°C. The disturbance has not been able to generate enough thunderstorms to moisten the surrounding atmosphere much, and dry air may continue to slow down development over the next few days. The models take 97L to the west-northwest, bringing it near or over Puerto Rico or Hispaniola on Wednesday night. A track over the high mountains of Hispaniola would disrupt the circulation of 97L, forcing the storm to regroup on Thursday over the Southeast Bahamas and Turks and Caicos Islands. The best chance for development of 97L would appear to be on Friday, after the storm has finished its encounter with Hispaniola. This morning's 00Z run of the experimental GFDL ensemble--which produces 10 simulations with slightly varying initial conditions to create a plume of potential storm tracks--foresees that once 97L organizes into a tropical depression, it might take only two days for it to intensify into a hurricane to the north of Hispaniola. The wave will bring heavy rain showers to the Lesser Antilles islands on Tuesday and Wednesday, and this activity will likely spread to Puerto Rico, the Virgin Islands, the Dominican Republic, and Haiti on Wednesday and Thursday. These rains will be capable of causing life-threatening flash flooding and mudslides in mountainous regions of Puerto Rico and Hispaniola. Of our three reliable models for predicting genesis, the UKMET, GFS, and European models, only the UKMET model develops the disturbance, predicting it will become a tropical depression over the Central Bahamas on Saturday. There will be a strong trough of low pressure along the U.S. East Coast this weekend, which will be capable of turning 97L to the north before the storm can hit the U.S. In their 8 am EDT Tuesday Tropical Weather Outlook, NHC left the 5-day odds of formation of 97L at 50%, and 2-day odds at 20%. The Hurricane Hunters are on call to investigate 97L Wednesday afternoon. The flight scheduled for today will likely be cancelled. The Hurricane and Severe Storm Sentinel Mission, a 5-year field project utilizing two remotely crewed Global Hawk aircraft to overfly tropical storms and hurricanes, will have one of their aircraft investigate 97L today, and again on Wednesday. You can follow the progress of the aircraft using NASA's live-plane tracker map (Global Hawk AV6 is tail number NASA872, and Global Hawk AV1 is tail number NASA871.)

98L off the coast of Africa and a Yucatan Peninsula tropical wave
A tropical wave that emerged from the coast of Africa on Monday (Invest 98L) is expected to track northwest over the Cape Verde Islands. This course will take 98L into a region of ocean where historically, very few tropical cyclones have made the long journey across the Atlantic to affect North America. In their 8 am EDT Tuesday Tropical Weather Outlook, NHC put the 5-day odds of development at 20%.

A tropical wave over Mexico's Yucatan Peninsula has a respectable area of heavy thunderstorms associated with it that is bringing heavy rains. This activity will push over the extreme Southern Gulf of Mexico's Bay of Campeche on Wednesday. The wave will have two days over water to develop before moving ashore on the Mexican coast between Veracruz and Tampico on Friday. In their 8 am EDT Tuesday Tropical Weather Outlook, NHC put the 5-day odds of development at 30%, and 2-day odds at 20%.

Jeff Masters

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Levi,do you have data from the Global Hawk mission?
Member Since: April 29, 2009 Posts: 75 Comments: 14904
216. Relix
Quoting 208. wunderkidcayman:

Where do you see it moving to



It's definitely not moving 285 degrees in fact it doesn't even look like its moving true 270 degrees and its most likely going to miss those islands



I am gonna take a guess and say its moving towards the Cayman Islands, am I right?
Member Since: August 3, 2006 Posts: 0 Comments: 2741
215. JRRP
Quoting wunderkidcayman:

Where do you see it moving to



It's definitely not moving 285 degrees in fact it doesn't even look like its moving true 270 degrees and its most likely going to miss those islands


put in rock
285 to me
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Quoting 208. wunderkidcayman:

Where do you see it moving to



It's definitely not moving 285 degrees in fact it doesn't even look like its moving true 270 degrees and its most likely going to miss those islands



no, not 270, 280 would seep about right we dont even have a depression yet so trying to guess the movment would be difficult.
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Quoting 207. LargoFl:


Send some our way. Only .20" of rain in 3 days here near Orlando, despite numerous storms in the area each of the last 3 days.
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Quoting 184. wunderkidcayman:

No I did not


Yeah slowly getting there



You most certainly did In your post#486 9/2/13 1:58 PM


QUOTE: wunderkidcayman


Look at BEST track file its moving W not E
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Montserrat sustain E winds 23Kt
Member Since: August 12, 2007 Posts: 0 Comments: 134
I'm just not feeling the models on 97L. Just a couple of days ago they had the African low doing loop-de-loops after moving N. Now they show it with a SSW movement.Why do they expect 97L to make a turn? Is the ULL still in place over S. Fl. straits? I thought that had moved out...? Happy for any clarity on the reason for the track forecast. Why are there no models on the map on WU opening pg for the BOC low?
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Quoting 195. Chucktown:


But, its gaining more latitude than longitude. Looks like a glancing blow to Hispanola and PR then OTS. We may get Gabs out it after all.


The GFS and its derivative models still look plain wrong to me, generating something out of nothing to the northeast of the main complex. I think the Bahamas will still have to deal with weather from 97L. It's not going OTS as easily as all that, but we still have to see where it's centered after dealing with Hispaniola, which can always change the game.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
Quoting 193. JRRP:
i do not see 97L moving west
Link

Where do you see it moving to

Quoting 198. Relix:
Circulation is there, cyclonic turning is there, and moving at 285 degrees making a beeline for the Mona Passage between PR and RD it seems.


It's definitely not moving 285 degrees in fact it doesn't even look like its moving true 270 degrees and its most likely going to miss those islands

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HWRF forecast models predict 97L to be a hurricane by the 6th of September...

Time of model run: 2100 THU SEP 05 Approx. location:20.6N 67.6W Pressure:(981) mph:89 kts:(77)

Gets even stronger later according to it...

Time of model run:2100 SAT SEP 07 Approx. location:24.6N 66.1W Pressure:(969)mph:98 kts:(85)
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Quoting 201. hurricanes2018:
THE HURRICANE IS MOVING WEST HERE!



only for a short period this looks like a classic setup for Bermuda to geta hit we'll see
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WOW! A BIG HURRICANE MOVING TO THE WEST!
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still moving wnw I think its cuba bound, moving nw into Bah then out to see from there.
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For what I can see, 97L will move as predicted by the GFS and be shredded over the Hispaniola. If it survivies the island, then we will see if it becomes anything. But I would not put my money on it yet.
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THE HURRICANE IS MOVING WEST HERE!
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From newspaper this morning from one of our Ken Kaye!

'Fish storms' nourish marine life, balance the atmosphere


By Ken Kaye, Sun Sentinel
5:58 p.m. EDT, September 2, 2013



They're called "fish storms" because they curve out to sea and seemingly do little more than hassle a bunch of tuna, marlins and swordfish.

But as they churn over open water, tropical storms and hurricanes actually provide a strong boost to marine life by uprooting nutrients from the ocean floor and driving them to the surface, experts say.

That provides a banquet for everything from shrimp to sharks, as plankton dine on the nutrients, small fish gorge on the plankton and bigger fish feast on the little fish.



"The agitation from storm events brings up nutrients locked up in the sediment," said Jerald Ault, a marine biology professor at the University of Miami. "Then it moves through the food chain."

So far this year, there have been three such fish storms — so called by meteorologists and weather buffs — in Chantal, Dorian and Erin, and in the past five years 38.





Although a single storm isn't enough to change these patterns, several tropical systems following the same general path have drawn marine creatures to specific areas, such as offshore regions of Florida, Africa and the Caribbean, Ault said.

Fish in those areas tend to spawn in the nutrient and oxygen rich waters, and the survival rates of their young tend to be better, noted Ault, who conducts surveys of fish populations around Florida.

When fish congregate in storm-traveled waters, birds and commercial fishermen soon follow.

"Fishermen know where the fish are most productive, and in today's world, they use satellite technology to find them," said Ault, who teaches at UM's Rosenstiel School of Marine and Atmospheric Science.

While hurricanes help nourish fish, fish help feed information to hurricane forecasters, Ault added.

Because they like to swim in waters just warm enough for tropical storms to develop, tarpon have been tagged with satellite-linked devices, which measure sea temperatures. That data is transmitted to computer models used by the National Hurricane Center.

"The tarpon are helping scientists to get ocean data, specifically heat content, which in turn helps forecast data," he said.

While they may be better fed after a storm passes, what do fish do when tropical storms and hurricanes are about to hit their area?

No one knows for sure because there have been no specific studies on the subject. But Ault suspects fish are fully aware when storms approach because "they are very attuned to barometric pressure and temperature changes. The fish literally feel the changes," he said.

Bigger fish probably swim out of the way or dive as deep as they to ride out the storm. Small, weak or less mobile fish are vulnerable to being killed.

"Certainly, they hunker down," Ault said.

Aside from helping fish, tropical systems, whether they hit land or not, also help keep equilibrium in the atmosphere. They distribute heat around the globe and prevent the seas from getting too hot, experts say.

"They play a role in making the whole atmosphere work," said Hugh Willoughby, a research professor in the Earth and Environment Department of Florida International University.

With their powerful circulations acting like an oil drilling rig, hurricanes dredge up cold water from the depths and at the same time release ocean heat into the atmosphere.

This heat transfer process, in combination with other large-scale atmospheric forces, helps regulate temperatures, preventing winters from getting too cold and summers too hot, primarily in the Northern Hemisphere, Willoughby said.

While much of how hurricanes interact with the ocean and atmosphere remains unknown, scientists suspect that tropical systems prevent the oceans from getting too hot and salty to sustain life.

If there were no hurricanes, the atmosphere would have to develop new mechanisms to release heat, such as increased thunderstorm activity, Willoughby said.

"You would think the atmosphere is simple, just being air and water," he said. "But it's as complicated as a living thing."

kkaye@tribune.com or 954-572-2085.


Copyright © 2013, South Florida Sun-Sentinel
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Quoting 187. Torito:
97L seems to starting to become organized now...




still "popcorn" in nature we'll see how the rest of the day and into overnight goes.
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198. Relix
Circulation is there, cyclonic turning is there, and moving at 285 degrees making a beeline for the Mona Passage between PR and RD it seems.
Member Since: August 3, 2006 Posts: 0 Comments: 2741
Quoting 170. WoodyFL:
on every run the models keep moving 97 further east and north.






What a difference a day makes! The Azober high must have weakened awful quick.
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HWRF forecast models predict 97L to be a hurricane by the 6th of September...

Time of model run: 2100 THU SEP 05 approx. location:20.6N 67.6W Pressure:(981) knots:89 MPH:(77)
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Quoting 187. Torito:
97L seems to starting to become organized now...



But, its gaining more latitude than longitude. Looks like a glancing blow to Hispanola and PR then OTS. We may get Gabs out it after all.
Member Since: August 27, 2006 Posts: 0 Comments: 1785
Look how well define the wind barbs depict the circulation.
Member Since: August 12, 2007 Posts: 0 Comments: 134
193. JRRP
i do not see 97L moving west
Link
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Quoting 187. Torito:
97L seems to starting to become organized now...



In time for Global Hawk to see how organized it is.
Member Since: April 29, 2009 Posts: 75 Comments: 14904
There is west winds all over South America Venezuela coast. check wundermap
Member Since: August 12, 2007 Posts: 0 Comments: 134
Quoting 187. Torito:
97L seems to starting to become organized now...


Slowly but surely getting there
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Hazardous Weather Outlook

------------------------------------------------- -------------------------------
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
744 AM CDT TUE SEP 3 2013

GMZ130-132-135-150-155-170-175-041245-
LAGUNA MADRE FROM THE PORT OF BROWNSVILLE TO THE ARROYO COLORADO-
LAGUNA MADRE FROM THE ARROYO COLORADO TO 5 NM NORTH OF PORT
MANSFIELD TX-
LAGUNA MADRE FROM 5 NM NORTH OF PORT MANSFIELD TO BAFFIN BAY TX-
COASTAL WATERS FROM PORT MANSFIELD TO THE RIO GRANDE OUT 20 NM-
COASTAL WATERS FROM BAFFIN BAY TO PORT MANSFIELD OUT 20 NM-
WATERS FROM PORT MANSFIELD TO THE RIO GRANDE EXTENDING FROM 20 TO
60 NM-
WATERS FROM BAFFIN BAY TO PORT MANSFIELD EXTENDING FROM 20 TO
60 NM-
744 AM CDT TUE SEP 3 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE GULF OF MEXICO AND THE
LAGUNA MADRE.

.DAY ONE...TODAY AND TONIGHT.

TROPICAL FUNNELS OR WATERSPOUTS WILL BE POSSIBLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

SHOWERS AND THUNDERSTORMS WILL INCREASE WEDNESDAY THROUGH
SATURDAY...PRODUCING UNSETTLED MARINE WEATHER TROPICAL FUNNELS OR
WATERSPOUTS WILL BE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

$$
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The Dvorak fixes from today.


DATE TIME LAT LON CLASSIFICATION ID NAME
20130903 1145 14.5 62.9 Too Weak 97L 97L
20130903 0545 14.8 61.4 T1.0/1.0 97L 97L
20130902 2345 14.3 60.3 Too Weak 97L 97L
20130902 1745 14.0 59.7 Too Weak 97L 97L
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97L seems to starting to become organized now...

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Quoting 178. hu2007:
97L getting better organize :O


AGREE!
Member Since: August 12, 2007 Posts: 0 Comments: 134
A new tropical storm with a 1007 mb!!
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Quoting 175. WoodyFL:


But you were telling everyone to look at the BEST track data yesterday.

No I did not

Quoting 178. hu2007:
97L getting better organize :O

Yeah slowly getting there
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Quoting 170. WoodyFL:
on every run the models keep moving 97 further east and north.






Not surprised to see this now that we are into September. With the pattern that has been in place, I believe the US East Coast is most likely safe from landfalls for the remainder of 2013. This is, of course, assuming something can actually get its act together for any length of time.
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Quoting 170. WoodyFL:
on every run the models keep moving 97 further east and north.






Don't bother with them just disregard them for now till BEST tack data can plot the positions correctly
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Quoting 173. GTstormChaserCaleb:
I'm looking at this deep trough coming into the Southeast.




thats why a recurve will occur, theres no way to aviod that.
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Nam for Saturday.......................
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Euri has a nice system 240 Hours down the road which has the possibility of affecting Bermuda. I guess we should keep an eye on that one when it happen. If it happens.
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97L getting better organize :O
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Quoting 163. EyEtoEyE:
Hello bloggers , Have all of you seen the MSNBC story , on this years hurricane season , the forecasters , they are still calling for an above average season !



yawn they are vary worng on that


what we may end up having is a well below average season
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Quoting 167. wunderkidcayman:


Even so all them models are out the door and in the trash because of where the BEST track data plotted the location which was incorrect


But you were telling everyone to look at the BEST track data yesterday.
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Quoting 165. Levi32:


No, the computer did not change the fundamental problems that the GFS has always had. These issues with northeast feedback in the tropics have been around for years.


97l has a shot today levi, trade winds are taking their toll however.
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I'm looking at this deep trough coming into the Southeast.

Member Since: June 30, 2013 Posts: 12 Comments: 8774
look at invest 98L 1011 MB LOW AND MAYBE INVEST 90L WITH 1007MB
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THE CARIBBEAN SEA...
IN THE UPPER-LEVEL...AN ELONGATED LOW CONTINUES OVER THE WESTERN
GULF W OF 90W N OF 21N WHILE AN ELONGATED RIDGE EXTENDS AN AXIS
ACROSS SOUTHERN FLORIDA TO THE WESTERN CARIBBEAN SEA. THIS IS
GENERATING UPPER-LEVEL DIFFLUENCE WHICH IS SUPPORTING NUMEROUS
MODERATE/ISOLATED STRONG CONVECTION AND TSTMS OVER THE WESTERN
CARIBBEAN N OF 17N W OF 82W AS WELL AS SCATTERED MODERATE
CONVECTION FROM 13N-17N BETWEEN 81W-85W. ISOLATED SHOWERS AND
TSTMS ARE OVER THE SOUTHERN CARIBBEAN S OF 11N ASSOCIATED WITH
THE MONSOON TROUGH WHICH MOVES ACROSS PANAMA TO A 1008 MB LOW
OVER NORTHERN COLOMBIA. AN ELONGATED UPPER-LEVEL LOW IS OVER THE
CENTRAL CARIBBEAN WHILE A RIDGE AXIS EXTENDS INTO THE EASTERN
BASIN FROM A HIGH CENTERED IN THE TROPICAL ATLC NEAR 16N53W.
THIS IS GENERATING UPPER LEVEL DIFFLUENCE WHICH IS SUPPORTING
CLOUDINESS AS WELL AS ISOLATED SHOWERS OVER HISPANIOLA. THE LOW
PRESSURE ASSOCIATED WITH THE TROPICAL WAVE IN THE EASTERN
CARIBBEAN SEA HAS DISSIPATED AND THE WAVE AXIS HAS MOVED
SLIGHTLY WEST CROSSING THE LESSER ANTILLES EARLY THIS MORNING.
ITS AXIS EXTENDS FROM 19N61W TO 11N61W. SCATTERED MODERATE
CONVECTION IS FROM 15N-17N BETWEEN 59W-63W WITH ISOLATED SHOWERS
ELSEWHERE FROM 12N-19N BETWEEN 58W-66W. THE WAVE WILL CONTINUE
TO MOVE WESTWARD AND WILL START MOVING ACROSS EASTERN PUERTO RICO
TONIGHT. THE WAVE IS EXPECTED TO MOVE OVER THE MONA PASSAGE BY
EARLY THURSDAY. HEAVY RAINFALL ARE EXPECTED FOR PUERTO RICO AND
HISPANIOLA.

HISPANIOLA...
AN ELONGATED UPPER-LEVEL LOW IS OVER THE CENTRAL CARIBBEAN WHILE
A RIDGE AXIS EXTENDS INTO THE EASTERN BASIN FROM A HIGH CENTERED
IN THE TROPICAL ATLC NEAR 16N53W. THIS IS GENERATING UPPER LEVEL
DIFFLUENCE WHICH IS SUPPORTING CLOUDINESS AS WELL AS ISOLATED
SHOWERS OVER HISPANIOLA. THE TROPICAL WAVE CURRENTLY IN THE
EASTERN CARIBBEAN IS EXPECTED TO BE ALONG THE MONA PASSAGE BY
EARLY THURSDAY. HOWEVER...WEATHER CONDITIONS WILL START TO
DEGENERATE WED MORNING AS THE WAVE MOVES WESTWARD ACROSS PUERTO
RICO PUSHING FORWARD AN ENVELOPE OF HIGH MOISTURE.

THE ATLANTIC OCEAN...
BESIDES THE TROPICAL WAVES ALREADY DISCUSSED...SURFACE RIDGING
ANCHORED BY A SET OF HIGH PRESSURE CENTERS N OF THE AREA
DOMINATES THE REMAINDER BASIN N OF 20N WHICH ALONG WITH DRY
STABLE AIR SUPPORTS FAIR WEATHER. A NEW TROPICAL WAVE IS
EXPECTED TO COME OFF THE AFRICAN COAST LATE TONIGHT.
ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE MARGINALLY FAVORABLE
FOR DEVELOPMENT OF THIS WAVE OVER THE NEXT FEW DAYS WHILE THE
DISTURBANCE MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT 10 TO
15 MPH. THIS SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

FOR ADDITIONAL INFORMATION PLEASE VISIT
WWW.HURRICANES.GOV/MARINE

$$
NR
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on every run the models keep moving 97 further east and north.




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Winds are increasing at the buoy to the NNW of 97L, 28Kt


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Quoting 161. LargoFl:
BAMS continues to say 97 is headed to the gulf......


Even so all them models are out the door and in the trash because of where the BEST track data plotted the location which was incorrect
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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