Lesser Antilles Disturbance 97L a Threat to Develop

By: Dr. Jeff Masters , 2:46 PM GMT on September 01, 2013

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A tropical wave over the Lesser Antilles Islands (Invest 97L) is moving westward at 15 mph, and is bringing heavy rains and gusty winds to the islands. Top sustained winds in the islands as of 10 am AST Sunday were 26 mph at Monserrat. Heavy thunderstorm activity has sharply increased since Saturday, as seen on satellite loops. A large circulation is evident, with some westerly winds blowing to the south of the disturbance. However, the thunderstorms are poorly organized, and there is no sign of a well-organized surface circulation. Martinique radar shows some rotation to the echoes, though well-organized spiral bands are not evident, and do not appear to be forming. Wind shear has dropped to a moderate 10 - 20 knots over the system. An area of dry air from the Saharan Air Layer (SAL) surrounds 97L and is interfering with development.


Figure 1. Latest satellite image of Invest 97L.

Forecast for 97L
Wind shear is expected to be in the low to moderate range for the next five days, and ocean temperatures will be warm, 28 - 29°C. The disturbance is steadily moistening the atmosphere and is moving into a moister environment, so dry air will be less of an impediment to development as the week progresses. The main factor keeping the disturbance from developing over the next two days would appear to be the fact that 97L is quite large, and is stretched out from east to west over a wide expanse. Large, elongated systems like 97L usually take several days to consolidate and spin up. Another factor that will likely retard development is the presence of strong surface trade winds over the Eastern Caribbean ahead of 97L, south of the Dominican Republic. These strong trade winds are a common feature of the Eastern Caribbean, and make the region something of a hurricane graveyard. As the surface wind flow to the west of 97L accelerates into this wind max, air will be sucked from aloft downward towards the surface, creating sinking air, interfering with the formation of thunderstorm updrafts. The best chance for development of 97L would appear to be on Wednesday or Thursday, when the disturbance reaches the Central Caribbean. The wave will likely spread heavy rains to Puerto Rico, the Virgin Islands, and the Dominican Republic by Tuesday, and to Haiti by Wednesday. These rains will be capable of causing life-threatening flash flooding and mudslides in mountainous regions in 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 south of Haiti on Wednesday, and near Jamaica on Thursday. In their 8 am EDT Sunday Tropical Weather Outlook, NHC boosted the 5-day odds of formation of 97L to 30%, and the 2-day odds to 20%.


Video 1. You can see why landslides triggered by heavy rains from a tropical cyclone are among the most dangerous hazards of these storms, thanks to a dashboard cam that caught this extraordinary rock slide in Northeast Taiwan on August 31, 2013, after heavy rains from a cold front drenched the island with up to 200 mm (7.87") of rain in 24 hours. The rains fell upon soils already saturated by Thursday's torrential rains from Tropical Storm Kong-Rey, which dumped up to 482 mm (19") of rain on Taiwan, killing three people. The driver of the car caught in the rock slide survived with minor injuries. Thanks go to wunderground member Robert Speta for bringing this video to my attention. A separate video showing the damage to the car and the course of the rock slide is here.

Jeff Masters

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1255. SLU
Quoting 1234. stormpetrol:


I looked carefully at the loop again, simple as that :)



That's the old MLC from this morning. The LLC is NE of Barbados and drifting westwards.
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1254. JRRP
Quoting stormpetrol:


I looked carefully at the loop again, simple as that :)

ok... look at this
Member Since: August 16, 2007 Posts: 0 Comments: 5337
Quoting 1231. weatherlover94:



There is that chance it could be picked up and shot NE by the front yes.... it's a small chance right now though. I expect the models to go back and forth the next few days



Okay. So if it stays as a weak TS and goes under Cuba and then becomes a hurricane would it still turn North or would it continue west?
Member Since: December 26, 2012 Posts: 0 Comments: 75
Quoting 1238. DonnieBwkGA:



The storm would not be terribly strong in Florida with all the land interaction but it could still be devastating if the Lake Okeechobee basin gets a general 6+ inches of rain.

The hurricane was the first to directly strike Miami since Hurricane King in the 1950 season.[1] Cleo intensified rapidly just prior to landfall, bringing sustained winds of 100–105 mph (160 km/h–170 km/h) with gusts to 135 mph (215 km/h) to the Miami area, due to moving over water temperatures of 30 to 32 degrees Celsius and its compact size. Lightning was observed within the eyewall at the National Hurricane Center. The pressure fell to 967.6 mb (28.57 inches) in North Miami. Major damage was constrained to a 20–35 mile (30 km–50 km) wide strip from Miami to Melbourne,[3] in the form of broken glass, interior flooding, uprooted trees, overturned aircraft, power failures, and agriculture. Cleo cut power to 620,000 homes and businesses in southeast Florida.[27] At least two dozen fires blazed across Miami.[22] About a quarter of the grapefruit crop was lost within the Indian River citrus producing region. The storm surge reached 4–6 feet (1.2 m–1.8 m) between Miami and Pompano Beach. The highest rainfall total measured within Florida was 9.37 inches (240 mm) at Stuart.[28]

Although no 2 storms are alike this did happen as highlighted on bold and can happen again given the right conditions. A 105 mph with gusts of 135 mph are definitely plenty strong. I wouldn't discount anything even the possibility of a stronger storm.

In no way am I saying this invest will even come close to this but there is always the possibility.
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1251. VAbeachhurricanes
10:28 PM GMT on September 01, 2013
Warming cloud tops

Member Since: September 6, 2007 Posts: 0 Comments: 6068
1250. prcane4you
10:28 PM GMT on September 01, 2013
Quoting 1232. hydrus:
No...Mid October, but can go to end of October..Depends.
Waves and waves of trains to Grand Central never ends
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1249. Sfloridacat5
10:27 PM GMT on September 01, 2013
18z GFS at 174 hours. 97L hugging the north coast of Cuba.
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1248. jascott1967
10:27 PM GMT on September 01, 2013
95 degrees here in beautiful "downtown" Kem
Quoting 1232. hydrus:
No...Mid October, but can go to end of October..Depends.


Hurrican Zeta formed on December 29,2005a Cape Verde storm. Never know.
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1247. JRRP
10:27 PM GMT on September 01, 2013
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1246. hydrus
10:26 PM GMT on September 01, 2013
Quoting 1242. DonnieBwkGA:


I was imprecise. I should have said development of African waves in the eastern Atlantic becomes a lot less likely after 3 weeks.
Historically . Who really knows anymore with the wild patterns we observe these days.
Member Since: September 27, 2007 Posts: 1 Comments: 20506
1245. DonnieBwkGA
10:25 PM GMT on September 01, 2013
The Florida/Georgia part of the track reminds me of hurricane David back in 79. I would have liked to have seen that.
Member Since: June 29, 2013 Posts: 21 Comments: 1944
1244. unknowncomic
10:25 PM GMT on September 01, 2013
Look like more model agreement on "double trouble' in the tropics.
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1243. hydrus
10:24 PM GMT on September 01, 2013
Quoting 1233. 954FtLCane:

Yes, Cleo. She reads the future
I know. Miss Cleo tolt me I am going to be president of the U.S of A.

Member Since: September 27, 2007 Posts: 1 Comments: 20506
1242. DonnieBwkGA
10:24 PM GMT on September 01, 2013
Quoting 1232. hydrus:
No...Mid October, but can go to end of October..Depends.


I was imprecise. I should have said development of African waves in the eastern Atlantic becomes a lot less likely after 3 weeks.
Member Since: June 29, 2013 Posts: 21 Comments: 1944
1241. BahaHurican
10:24 PM GMT on September 01, 2013
Quoting 1235. PensacolaDoug:
1227:

I like that track better than one to Pensacola.
That's Only because u don't live in The Bahamas or S FL....
Member Since: October 25, 2005 Posts: 19 Comments: 21485
1240. prcane4you
10:24 PM GMT on September 01, 2013
Quoting 1189. wunderkidcayman:

Is that B B

xxx enjoy
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1239. weatherlover94
10:23 PM GMT on September 01, 2013
Great environment in its path


Link
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1238. DonnieBwkGA
10:22 PM GMT on September 01, 2013
Quoting 1227. 954FtLCane:



The storm would not be terribly strong in Florida with all the land interaction but it could still be devastating if the Lake Okeechobee basin gets a general 6+ inches of rain.
Member Since: June 29, 2013 Posts: 21 Comments: 1944
1237. hydrus
10:22 PM GMT on September 01, 2013
Quoting 1220. SFLWeatherman:
Link
Thank you kindly..
Member Since: September 27, 2007 Posts: 1 Comments: 20506
1236. airmet3
10:22 PM GMT on September 01, 2013
Quoting 1162. Tazmanian:
97L is likey going too go 70% for the next 48hrs 100% the next five days


I know the 5 day outlook is new, but do you think the NHC would go "near 100%" on a system at 5 days that is not already at "near 100%" at 48 hours.

From a science and statistics view, I would say no.

Carry on.
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1235. PensacolaDoug
10:22 PM GMT on September 01, 2013
1227:

I like that track better than one to Pensacola.
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1234. stormpetrol
10:22 PM GMT on September 01, 2013
Quoting 1223. JRRP:

i thought that you say 13n lol


I looked carefully at the loop again, simple as that :)
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1233. 954FtLCane
10:21 PM GMT on September 01, 2013
Quoting 1229. hydrus:
Cleo.? 64.?

Yes, Miss Cleo. She reads the future
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1232. hydrus
10:21 PM GMT on September 01, 2013
Quoting 1225. DonnieBwkGA:


The African wave train usually ends in about 3 weeks doesn't it?
No...Mid October, but can go to end of October..Depends.
Member Since: September 27, 2007 Posts: 1 Comments: 20506
1231. weatherlover94
10:21 PM GMT on September 01, 2013
Quoting 1228. Newswatcher:
Why do some models want 97L to continue to go west until Haiti and the it take a NW followed by a North turn? Is it supposed to be a strong TS and then get pulled north by a low coming off the SE USA?



There is that chance it could be picked up and shot NE by the front yes.... it's a small chance right now though. I expect the models to go back and forth the next few days
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1230. dopplergirl
10:21 PM GMT on September 01, 2013
Quoting 1173. Grothar:
Just when I thought I was out; they pull me back in. I just received a request from a blogger to make an announcement.

Significant blob imminent. (You happy now?)









Thank you, yes.
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1229. hydrus
10:20 PM GMT on September 01, 2013
Quoting 1227. 954FtLCane:
Cleo.? 64.?
Member Since: September 27, 2007 Posts: 1 Comments: 20506
1228. Newswatcher
10:18 PM GMT on September 01, 2013
Why do some models want 97L to continue to go west until Haiti and the it take a NW followed by a North turn? Is it supposed to be a strong TS and then get pulled north by a low coming off the SE USA?
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1227. 954FtLCane
10:18 PM GMT on September 01, 2013


This site would go,,......
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1226. HadesGodWyvern (Mod)
10:18 PM GMT on September 01, 2013
Japan Meteorological Agency
Tropical Cyclone Advisory #8
Gale Warning
TROPICAL STORM YUTU (T1316)
6:00 AM JST September 2 2013
==============================

Midway Island Waters

At 21:00 PM UTC, Tropical Storm Yutu (1002 hPa) located at 33.7N 176.9E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as almost stationary.

Gale Force Winds
=================
180 NM from the center in southeast quadrant
120 NM from the center in northwest quadrant

Dvorak Intensity: T2.5

Forecast and Intensity
========================
24 HRS: 34.5N 178.9E - 35 knots (CAT 1/Tropical Storm) Midway Island Waters
45 HRS: 36.0N 175.2W - 35 knots (CAT 1/Tropical Storm) South Of Aleutian Island
69 HRS: 37.5N 168.9W - 35 knots (CAT 1/Tropical Storm) South Of Aleutian Island

Japan Meteorological Agency
Tropical Cyclone Advisory #10
Gale Warning
TROPICAL STORM TORAJI (T1317)
6:00 AM JST September 2 2013
==============================

Near Okinawa Island

At 21:00 PM UTC, Tropical Storm Toraji (1002 hPa) located at 26.4N 125.0E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving north northeast slowly.

Gale Force Winds
===============
90 NM from the center

Dvorak Intensity: T2.5

Forecast and Intensity
========================
24 HRS: 28.1N 126.7E - 40 knots (CAT 1/Tropical Storm) Amami Islands
45 HRS: 29.0N 127.5E - 45 knots (CAT 1/Tropical Storm) East China Sea
69 HRS: 29.6N 127.7E - 45 knots (CAT 1/Tropical Storm) East China Sea
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1225. DonnieBwkGA
10:17 PM GMT on September 01, 2013
Quoting 1206. barbamz:
Still bad news about an above normal monsoon in India, but a new BBC weather video is hinting to a maybe early halt. I wonder whether this may affect the African wave train as well.

Over five million people hit by floods in northern India
Press TV, Sun Sep 1, 2013 1:11PM GMT
Indian officials say floods triggered by heavy monsoon rains have affected more than five million people in over a dozen districts of the northern Bihar state, as rain-swollen rivers burst their banks. ...

Indian Monsoon update
BBC weather video, 1 September 2013 Last updated at 12:42
BBC Weather's Chris Fawkes takes a look at the progress of the Indian Monsoon and when it is likely to withdraw.

Good night, stay well everybody!


The African wave train usually ends in about 3 weeks doesn't it?
Member Since: June 29, 2013 Posts: 21 Comments: 1944
1224. DonnieBwkGA
10:15 PM GMT on September 01, 2013
Quoting 1211. OracleDeAtlantis:
There's some dry air being pulled off of South America, which could be a problem as the evening progresses, and as the continent cools.



However, overall organization appears to be rapidly improving, at least visually since early this AM. If this thing consolidates quickly enough and avoids sucking in too much dry air tonight, it has the potential to become a very large system.

This could be the right side of my dream storm, if it takes this path.





Cool nighttime air wouldn't get more than 200 miles offshore before daylight. But the dry air may inhibit development later.
Member Since: June 29, 2013 Posts: 21 Comments: 1944
1223. JRRP
10:15 PM GMT on September 01, 2013
Quoting stormpetrol:


You can really see the LLC tightening up in this loop.

look at 14.7N/61.7W

i thought that you say 13n lol
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1222. hydrus
10:15 PM GMT on September 01, 2013
Quoting 1173. Grothar:
Just when I thought I was out; they pull me back in. I just received a request from a blogger to make an announcement.

Significant blob imminent. (You happy now?)







Well of course. Grab your laptop and monitor this cloud called 97L..:)
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1221. weatherlover94
10:14 PM GMT on September 01, 2013
Quoting 1217. Civicane49:


BB



EE
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1220. SFLWeatherman
10:14 PM GMT on September 01, 2013
Link
Quoting 1209. hydrus:
greetings. Do you have a link for that.? If so please post..
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1219. Sfloridacat5
10:14 PM GMT on September 01, 2013
18z GFS at 135 hours.
97L is just north of Cuba.
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1218. DonnieBwkGA
10:14 PM GMT on September 01, 2013
The HWRF makes a tiny hurricane in the eastern Caribbean. It gets bigger after land interaction. The development of a system like that in that region is historically rare.
Member Since: June 29, 2013 Posts: 21 Comments: 1944
1217. Civicane49
10:12 PM GMT on September 01, 2013
Quoting 1172. wunderkidcayman:
Poll time
What will 97L be at the 8pm TWO?
48hs. 5 days
A 40%. A 50%
B 50%. B 60%
C 60%. C 70%
D 70%. D 80%
E 80%. E 90%
F 90%. F near 100%


BB
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1216. SFLWeatherman
10:12 PM GMT on September 01, 2013
Member Since: May 23, 2012 Posts: 0 Comments: 4392
1215. Siker
10:12 PM GMT on September 01, 2013
Quoting 1172. wunderkidcayman:
Poll time
What will 97L be at the 8pm TWO?
48hs. 5 days
A 40%. A 50%
B 50%. B 60%
C 60%. C 70%
D 70%. D 80%
E 80%. E 90%
F 90%. F near 100%


BB
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1214. hydrus
10:12 PM GMT on September 01, 2013
Quoting 1182. SFLWeatherman:
WOW look at the HWRF!
Haiti would have some problems if that were to occur.
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1213. prcane4you
10:11 PM GMT on September 01, 2013
Quoting 1173. Grothar:
Just when I thought I was out; they pull me back in. I just received a request from a blogger to make an announcement.

Significant blob imminent. (You happy now?)







Great blobs party is about to begin.
Member Since: June 23, 2011 Posts: 0 Comments: 830
1212. hurricaneben
10:11 PM GMT on September 01, 2013
Quoting 1198. VAbeachhurricanes:
You guys are in dreamland, this thing still has another 72 hours at least to become anything. The vorticity way too weak and stretched still. As well as it will be fighting dry air.


Don't stop believing. The shear may drop to relatively low values in the short term anyway so that may be one thing working for it. But yeah in the next 24 hours, i dont think I see anything forming quite so soon. I could see it go up to code red by that time if not sooner, though.
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1211. OracleDeAtlantis
10:11 PM GMT on September 01, 2013
There's some dry air being pulled off of South America, which could be a problem as the evening progresses, and as the continent cools.



However, overall organization appears to be rapidly improving, at least visually since early this AM. If this thing consolidates quickly enough and avoids sucking in too much dry air tonight, it has the potential to become a very large system.

This could be the right side of my dream storm, if it takes this path.



Member Since: August 27, 2009 Posts: 0 Comments: 501
1210. DonnieBwkGA
10:11 PM GMT on September 01, 2013
1182--hmmmmm

Member Since: June 29, 2013 Posts: 21 Comments: 1944
1209. hydrus
10:11 PM GMT on September 01, 2013
Quoting 1196. SFLWeatherman:
greetings. Do you have a link for that.? If so please post..
Member Since: September 27, 2007 Posts: 1 Comments: 20506
1208. Seflhurricane
10:11 PM GMT on September 01, 2013
knowing the NHC the Next TWO will be 60% and 80 % next five days respectively. now lets see who is at the Helm tonight
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1207. Sfloridacat5
10:11 PM GMT on September 01, 2013
GFS does finally recognize 97L.
But the GFS takes it over all the Islands and 97L ends up over the Eastern tip of Cuba at 108 hours.

97L is the low near the Eastern tip of Cuba.
Member Since: September 16, 2007 Posts: 0 Comments: 6092
1206. barbamz
10:11 PM GMT on September 01, 2013
Still bad news about an above normal monsoon in India, but a new BBC weather video is hinting to a maybe early halt. I wonder whether this may affect the African wave train as well.

Over five million people hit by floods in northern India
Press TV, Sun Sep 1, 2013 1:11PM GMT
Indian officials say floods triggered by heavy monsoon rains have affected more than five million people in over a dozen districts of the northern Bihar state, as rain-swollen rivers burst their banks. ...

Indian Monsoon update
BBC weather video, 1 September 2013 Last updated at 12:42
BBC Weather's Chris Fawkes takes a look at the progress of the Indian Monsoon and when it is likely to withdraw.

Good night, stay well everybody!
Member Since: October 25, 2008 Posts: 51 Comments: 5643
1205. GTstormChaserCaleb
10:10 PM GMT on September 01, 2013
Quoting 1182. SFLWeatherman:
WOW look at the HWRF!
Not good at all. That would be a hurricane passing through the peninsula of Haiti.
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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.