Caribbean disturbance 99L a dangerous rainfall threat for Haiti, Jamaica, and Cuba

By: Dr. Jeff Masters , 4:12 PM GMT on October 20, 2012

Share this Blog
36
+

A tropical wave embedded in a large trough of low pressure (Invest 99L) covers a large portion of the Central Caribbean between Hispaniola and the northern coast of South America. This storm has the potential to be a dangerous rainfall threat for Haiti, Jamaica, and eastern Cuba. The disturbance is headed west at less than 5 mph, is over very warm waters of 29°C, and is in a moist environment. 99L has a large area of heavy thunderstorms that are beginning to show some organization, as seen on visible satellite loops. Wind shear is a low 5 - 10 knots, and is forecast to be in the low to moderate range, 5 - 20 knots, through Tuesday. This should allow for some steady development of 99L, and there has been a good deal of model support for 99L becoming a tropical depression by Wednesday. Steering currents favor a continued slow westward movement for 99L through Tuesday, which will bring a multi-day period of heavy rains to Haiti, Jamaica, and eastern Cuba beginning on Sunday. The Dominican Republic may also see some heavy rains, though not as great. On Wednesday, a strong trough of low pressure will approaching the Eastern U.S., and the GFS and ECMWF models predict that this trough will turn 99L to the north, bringing the storm into the southeast Bahama Islands on Thursday or Friday. In their 8 am EDT tropical weather outlook, NHC gave 99L a 30% chance of developing into a tropical cyclone by Monday morning. I put these odds higher, at 40%. An Air Force hurricane hunter aircraft is scheduled to investigate 99L on Sunday afternoon.


Figure 1. Morning satellite image of Invest 99L.

Invest 90L in the middle Atlantic
A tropical wave (Invest 90L) about 1000 miles east-northeast of the northernmost Lesser Antilles Islands is headed west-northwest at about 10 mph. The disturbance has a modest amount of heavy thunderstorms, as seen on visible satellite images, and has gotten tangled up with an upper-level low pressure system. This upper-level low is pumping cool, dry air into the disturbance, which will keep any development slow over the next few days. Wind shear is a high 20 - 25 knots, but is forecast to drop to the moderate range, 10 - 20 knots, Sunday through Monday. This may allow for some slow development of 90L before it encounters very high wind shear of 20 - 40 knots on Tuesday and Wednesday. None of the reliable computer models develop 90L into a tropical cyclone. It's unlikely that 90L will affect any land areas. In their 8 am EDT tropical weather outlook, NHC gave 90L a 20% chance of developing into a tropical cyclone by Monday morning.

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: 304 - 254

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20Blog Index

Quoting whitewabit:
What are the models seeing to turn it north so quickly??


Janiel Sucking.
Member Since: Posts: Comments:
299. whitewabit (Mod)
What are the models seeing to turn it north so quickly??
Member Since: August 17, 2005 Posts: 364 Comments: 31546
Member Since: July 17, 2009 Posts: 71 Comments: 26460
Member Since: July 17, 2009 Posts: 71 Comments: 26460
Quoting GraduateStudent2012:
Se esta debilitando, Grothar?
Si se convierte en un huracán usted puede venir a aquí ver los orificios nasales
Member Since: Posts: Comments:
Member Since: July 8, 2005 Posts: 259 Comments: 24166
Quoting GraduateStudent2012:
Se esta debilitando, Grothar?


Yo, o la tormenta?
Member Since: July 17, 2009 Posts: 71 Comments: 26460
310

WHXX01 KWBC 201843

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS NATIONAL HURRICANE CENTER MIAMI FL

1843 UTC SAT OCT 20 2012



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



DISTURBANCE INVEST (AL992012) 20121020 1800 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

121020 1800 121021 0600 121021 1800 121022 0600



LAT LON LAT LON LAT LON LAT LON

BAMS 14.6N 73.0W 15.0N 75.0W 15.2N 77.0W 15.0N 78.8W

BAMD 14.6N 73.0W 15.0N 74.7W 15.3N 76.0W 15.6N 77.0W

BAMM 14.6N 73.0W 14.9N 74.7W 15.1N 76.2W 15.1N 77.6W

LBAR 14.6N 73.0W 15.1N 74.7W 15.9N 76.1W 16.7N 77.5W

SHIP 25KTS 33KTS 43KTS 49KTS

DSHP 25KTS 33KTS 43KTS 49KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

121022 1800 121023 1800 121024 1800 121025 1800



LAT LON LAT LON LAT LON LAT LON

BAMS 14.6N 80.8W 13.3N 84.1W 11.8N 86.3W 11.2N 87.6W

BAMD 15.8N 77.8W 16.5N 79.0W 18.2N 79.7W 20.9N 80.3W

BAMM 15.1N 79.0W 14.8N 81.2W 14.4N 82.3W 16.4N 78.0W

LBAR 17.2N 78.5W 18.7N 80.1W 20.5N 80.9W 22.4N 80.6W

SHIP 57KTS 65KTS 64KTS 61KTS

DSHP 57KTS 65KTS 64KTS 61KTS



...INITIAL CONDITIONS...

LATCUR = 14.6N LONCUR = 73.0W DIRCUR = 280DEG SPDCUR = 8KT

LATM12 = 14.3N LONM12 = 71.6W DIRM12 = 282DEG SPDM12 = 10KT

LATM24 = 14.0N LONM24 = 69.7W

WNDCUR = 25KT RMAXWD = 120NM WNDM12 = 20KT

CENPRS = 1007MB OUTPRS = 1009MB OUTRAD = 180NM SDEPTH = S

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN


Member Since: July 15, 2006 Posts: 173 Comments: 54338
Member Since: July 17, 2009 Posts: 71 Comments: 26460
Member Since: July 17, 2009 Posts: 71 Comments: 26460
Member Since: July 17, 2009 Posts: 71 Comments: 26460
18z Surface Analysis adds low pressure.

Member Since: Posts: Comments:
Quoting allancalderini:
What happen to Cariboy haven`t see him since Rafael.


He got exactly what he was asking for.
Member Since: July 8, 2005 Posts: 259 Comments: 24166
Trying to edit previous post keeps giving me more! AGH!
Member Since: Posts: Comments:
Convergence still behind the upper divergence, but with the ULAC improving we should see convergence increase as well.

Member Since: Posts: Comments:
ULAC improving in 99L:

Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

Be sure to come back here after it avoids Florida so we can tell you how wrong you were.


just make sure to remember, if it does hit Florida you will need to come on here a praise his/her expertise.
Member Since: Posts: Comments:
.
Member Since: July 6, 2010 Posts: 113 Comments: 32257
Quoting 1441114:
First thing is I surely didn't use the good lord name I vain , you must be an idiot to think that , and yes COMPUTERS do lie period , end of STATEMENT ! Go on and think this won't strike Florida , and it will , there is nothing that says it will , just some brainless know it alls , who get get on here and talk about Obama and Romney , and other stuff ,but not what this blog is about , keep politics off this blog and use it real things that matter , who cares about them lying idiots , it's the weather we should all care about , three things u should not talk about is religion , politics , and a women's age. I doesn't matter who puts stuff in the computers , the are inaccurate 99 percent of the time !
Ok, I am an idiot but you are still here on the computer lol.
Member Since: Posts: Comments:


Pressure are low all across the W/SW/NW and central Caribbean.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Pressure keep going down still at buoy 42058. Now 1006.4. That's pretty low wind fr de sse
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Member Since: Posts: Comments:
274. Skyepony (Mod)
Fresh OSCAT ~3hrs old.

Member Since: Posts: Comments:

Member Since: Posts: Comments:
272. Skyepony (Mod)
ASCAT about 6hrs old.
Member Since: Posts: Comments:
Quoting stormwatcherCI:
He is in Miami so he didn't really feel Isaac.

Ummm...Isaac hit s fla pretty strongly. The amount of rain and wind squalls were comparable to any strong TS I ever remember striking and I live just north of Ft Laud....
He was something to write about.
A storm that size going thru key west and the amount of rain and wind this far way was pretty impressive if you ask me.
Member Since: Posts: Comments:
Link
Member Since: Posts: Comments:
Member Since: Posts: Comments:
It's a bit out there, but GFS has been pointing to a development in the EPAC now for a couple days crossing the Baja and its remnant moisture field crossing into S and then into the Gulf of Mexico. This is the culprit's 500mbar vorticity at 180hrs.



Last night its moisture field went up into SE Texas, that appears to have changed since yesterday. Additionally, the trough that was going to barrel on through has moved further north. I forsee the next 8-10 days to be somewhat uncertain, and while nice folks at CPC are pretty good at what they do, we could use a bit of rain here across the state.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting GraduateStudent2012:


That sneeze was no storm, UNDERSTOOD?
ok
Member Since: October 15, 2011 Posts: 0 Comments: 4401
I'm worried about those untapped warm waters and low wind shear , gotta a feeling 99L might be a major. It's in a very ticklish spot at this time of year in Season.
Member Since: Posts: Comments:
Quoting allancalderini:
I may say that most of the models take this to Cuba.I thought you Receive Isaac in August? or it didn`t affect you?
He is in Miami so he didn't really feel Isaac.
Member Since: Posts: Comments:
Quoting GeorgiaStormz:


so what are you predicting?
Could this really be a major hurricane in the caribbean?
bomb out like wilma?
Any chance it could hit FL in your opinion?
Because from what ive seen im going strong TS/ Cat 1 over the Greater Antilles and out to sea like rafael.

anything could happen
for some insite,i will look at potential analogs
Member Since: Posts: Comments:
Quoting GeorgiaStormz:


so what are you predicting?
Could this really be a major hurricane in the caribbean?
bomb out like wilma?
Any chance it could hit FL in your opinion?
Because from what ive seen im going with TS over the Greater Antilles and out to sea like rafael.

It's always possible that 99L could become a major, but I wouldn't forecast it. I do think there is the potential for it to become a hurricane before moving across East Cuba and into the East Bahamas. I doubt this makes a direct hit on Florida, although rainfall and gusty winds from the outer fringes of the storm may be felt.
Member Since: July 6, 2010 Posts: 113 Comments: 32257
NAEFS model at 174 hours......................
Member Since: Posts: Comments:
Quoting stormchaser19:
GFS is going to Shut up a lot of people here again....All the year with this dilemma and the result we all knows.... hE WINS :P

true,but i am still bothered about sandy and the spongebob jokes that no doubt will follow her
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

It has a very favorable environment. It's up to it about how intense it wants to become. Wind shear is low, heat content and sea surface temperatures are high, and trade winds are slow.


so what are you predicting?
Could this really be a major hurricane in the caribbean?
bomb out like wilma?
Any chance it could hit FL in your opinion?
Because from what ive seen im going strong TS/ Cat 1 over the Greater Antilles and out to sea like rafael.
Member Since: Posts: Comments:
GFS at 177 hours,just looked at it from 140 hours on..doesnt come to florida according to ther latest GFS run..BUT..that could change even by tomorrow,so stay tuned to your local warnings ok.................................
Member Since: Posts: Comments:
The GFS wants to cool the whole US off:
Member Since: Posts: Comments:
A good analog for 99L may be Hurricane 11 of 1924.

Member Since: Posts: Comments:
Member Since: Posts: Comments:

Viewing: 304 - 254

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20Blog 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

Partly Cloudy
50 °F
Partly Cloudy