97L more organized, could be a tropical depression by Wednesday

By: Dr. Jeff Masters , 12:55 GMT le 05 octobre 2010

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A large region of disturbed weather (Invest 97L) is bringing heavy rain showers and strong wind gusts to the Lesser Antilles Islands and waters near Puerto Rico, the Virgin Islands, and the Dominican Republic. At 8:30am AST this morning, Charlotte Amalie in the Virgin Islands recorded a wind gust of 52 mph in a heavy rain squall. Long range radar out of Puerto Rico shows that the echoes associated with 97L are slowly growing more organized, and now have a broad circulation, centered just north of the Virgin Islands. This broad circulation is also suggested by recent visible satellite loops. Satellite imagery also shows that low-level spiral bands are slowly developing over the northern Lesser Antilles islands, to the east of the center of circulation. Martinique radar shows a modest amount of heavy thunderstorm activity over the Lesser Antilles, and rainfall amounts of 1 - 3 inches have been common in the islands over the past two days. An upper level trough of low pressure is contributing to the heavy rain showers by making the atmosphere more unstable. This same trough is also bringing moderate wind shear of 10 - 15 knots and pumping dry air into the west side of 97L. These impacts should keep 97L from developing into a tropical depression today.


Figure 1. Morning satellite image of Invest 97L.

Forecast for 97L
Tonight and Wednesday morning, the upper-level trough to 97L's west is forecast to weaken. This will significantly reduce the amount of dry and and wind shear affecting the storm, and 97L should be able to organize into a tropical depression by Wednesday afternoon, when the Hurricane Hunters are scheduled to pay their first visit. The SHIPS model predicts that wind shear over 97L will fall to the low range, 5 - 10 knots, by Wednesday. The current northwest motion of 97L should keeps its center from crossing Hispaniola. All of the major computer models show development of 97L into a tropical depression by Wednesday night, just north or northeast of Hispaniola. By Thursday, a passing trough of low pressure is expected to pull 97L to the northeast away from Hispaniola, and rains should end by Friday on the island. NHC is giving 97L a 60% chance of developing into a tropical depression by Thursday. Since the center of this potential Tropical Storm Otto is not expected to pass over any land areas, rainfall will be the primary threat. The Dominican Republic and Puerto Rico are most at risk of flooding rains from the storm, which could bring 3 - 6 inches of rain through Thursday. Haiti and the Turks and Caicos Islands are at less risk, since the dry air and lingering wind shear from the upper-level trough to 97L's west will keep heavy thunderstorm development lower on the west side of the storm. Flash flood watches are posted for the Virgin Islands and Puerto Rico for today through Wednesday, and heavy rains will continue in the northern Lesser Antilles Islands through Wednesday.

Elsewhere in the tropics
Most of the models indicate the possibility that a strong tropical disturbance or tropical depression forming in the Southern Caribbean, off the coast of Nicaragua, 6 - 7 days from now.

"Hurricane Haven" airing this afternoon
My live Internet radio show, "Hurricane Haven", will be airing again today at 4pm EDT. The call in number is 415-983-2634, or you can post a question to broadcast@wunderground.com. Be sure to include "Hurricane Haven question" in the subject line.

Today's show will be about 20 minutes, and you can tune in at http://www.wunderground.com/wxradio/wubroadcast.h tml. The show will be recorded and stored as a podcast. I'll discuss 97L, and the odds of the U.S. getting a major hurricane strike during what remains of hurricane season.

Jeff Masters

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851. houston144
01:31 GMT le 07 octobre 2010
A "subtropical" storm with a name?

are we going to start naming Northeasters now?
Member Since: 26 août 2008 Posts: 0 Comments: 33
850. hydrus
14:36 GMT le 06 octobre 2010
Quoting cat5hurricane:
Waves, yes. But CV season is most likely toast for 2010.
Every other year or so, I see one of the African Waves make it to the Caribbean. If conditions are right. they can form.
Member Since: 27 septembre 2007 Posts: 1 Comments: 22604
849. cmahan
13:45 GMT le 06 octobre 2010
Quoting Patrap:
Ship treading thru the Fog near Audubon Bend on the Miss River.



That's gorgeous... I love pictures like that.
Member Since: 7 septembre 2010 Posts: 0 Comments: 155
848. sailingallover
13:19 GMT le 06 octobre 2010
AMAZING amount of rain last night.. not sure how much but judging from my dingy I say 8-12" It was half full twice and about 3" in again this morning which probably translates to 1.5" due the the Tubes contribution.
Member Since: 1 septembre 2009 Posts: 23 Comments: 1007
846. hydrus
13:11 GMT le 06 octobre 2010
A couple of African waves cruising along...
Member Since: 27 septembre 2007 Posts: 1 Comments: 22604
845. kmanislander
13:08 GMT le 06 octobre 2010
Quoting cat5hurricane:

My memory is only good for 14 and a half hours.


LOL
Member Since: 19 août 2006 Posts: 0 Comments: 15948
842. GeoffreyWPB
13:07 GMT le 06 octobre 2010
Quoting kmanislander:
Good morning

The vorticity split between SD 17 and the area South of the DR started last night and continues this morning. This is the scenario depicted by the models that develop another cyclone in the SW Caribbean from this energy that is forecast to move off to the WSW to a position just North of Panama in the coming days

Member Since: 10 septembre 2007 Posts: 0 Comments: 11539
841. kmanislander
13:06 GMT le 06 octobre 2010
Quoting cat5hurricane:
Makes sense. I didn't think it disappeared completely.


We chatted about this yesterday morning.

GFS @ 84 hrs



Member Since: 19 août 2006 Posts: 0 Comments: 15948
839. Neapolitan
13:05 GMT le 06 octobre 2010
NEW BLOG
Member Since: 8 novembre 2009 Posts: 4 Comments: 13797
833. kmanislander
13:01 GMT le 06 octobre 2010
Good morning

The vorticity split between SD 17 and the area South of the DR started last night and continues this morning. This is the scenario depicted by the models that develop another cyclone in the SW Caribbean from this energy that is forecast to move off to the WSW to a position just North of Panama in the coming days.

Member Since: 19 août 2006 Posts: 0 Comments: 15948
830. weatherguy03
12:59 GMT le 06 octobre 2010
Tropical Update Oct. 6th. 2010
Member Since: 5 juillet 2005 Posts: 592 Comments: 29708
827. Orcasystems
12:57 GMT le 06 octobre 2010
Quoting PensacolaDoug:





snort snort chuckle chuckle.


ROFLMAO.... Hmm what was that about a stopped clock
Member Since: 1 octobre 2007 Posts: 81 Comments: 26516
825. PensacolaDoug
12:55 GMT le 06 octobre 2010
Quoting Neapolitan:


That's because you're not always wrong. ;-)





snort snort chuckle chuckle.
Member Since: 25 juillet 2006 Posts: 0 Comments: 661
822. Neapolitan
12:54 GMT le 06 octobre 2010
Still a 30-knot, 1001 mb subtropical depression (with some 34-knot winds in the NE quadrant), says ATCF:

AL, 17, 2010100612, , BEST, 0, 227N, 677W, 30, 1001, SD, 34, NEQ, 0, 0, 0, 0, 1008, 240, 80, 0, 0, L, 0, , 0, 0, SEVENTEEN, M,
Member Since: 8 novembre 2009 Posts: 4 Comments: 13797
821. Neapolitan
12:53 GMT le 06 octobre 2010
Quoting PensacolaDoug:


You see Nea? We don't always disagree!


That's because you're not always wrong. ;-)
Member Since: 8 novembre 2009 Posts: 4 Comments: 13797
819. KEEPEROFTHEGATE (Mod)
12:52 GMT le 06 octobre 2010
where is that hammer
Member Since: 15 juillet 2006 Posts: 178 Comments: 56021
818. Orcasystems
12:52 GMT le 06 octobre 2010
Quoting ShenValleyFlyFish:
I find it just as much fun pushing the "!" and "-" buttons. Then they go away for good and I don't clog up my Ignore list. ;P~


I find if I slap them on ignore.. I enjoy my morning coffee.... if I read them..I have a tendency of getting peeved... and I have gone almost two years with out blowing my cool and getting a 24 hour ban :)

Its that SNAG, S&I part of me kicking in ;)
Member Since: 1 octobre 2007 Posts: 81 Comments: 26516
817. PensacolaDoug
12:52 GMT le 06 octobre 2010
STD17 got that "sceaming eagle" look to it .
Member Since: 25 juillet 2006 Posts: 0 Comments: 661
813. PensacolaDoug
12:48 GMT le 06 octobre 2010
Quoting Neapolitan:
PLEASE stop quoting the foul-mouthed, off-topic kiddies. The moron with the mixed case name and Jeff9641 need to have every post flagged and minused; they'll be gone soon enough. In the meantime: stop quoting them!!!


You see Nea? We don't always disagree!
Member Since: 25 juillet 2006 Posts: 0 Comments: 661
808. NEwxguy
12:46 GMT le 06 octobre 2010
When you ignore him and all who are quoting him,blog gets very quiet.
Member Since: 6 septembre 2007 Posts: 888 Comments: 15988
805. Patrap
12:45 GMT le 06 octobre 2010
Asia Floods: Indonesia, China Among Hardest-Hit

LAODE MURSIDIN | 10/ 6/10 08:23 AM |



TELUK WONDAMA, Indonesia — Helicopters dropped food to isolated villages and security forces helped clear debris and search for survivors as the number of people killed by floods and landslides across Asia climbed Wednesday to nearly 110.

Three-quarters of the deaths were in eastern Indonesia, where days of torrential downpours caused mud and debris to crash into hillside villages, damaging thousands of homes. Twenty-six fatalities were reported in Vietnam.

On the nearby Chinese island of Hainan, 64,000 people had to be evacuated.
Member Since: 3 juillet 2005 Posts: 428 Comments: 129833

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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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