Caribbean disturbance 94L dumping heavy rains on Jamaica

By: Dr. Jeff Masters , 4:44 PM GMT on June 05, 2011

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A large, wet, and disorganized tropical disturbance (Invest 94L) continues to spread heavy rain to the Central Caribbean near Jamaica. Rain has fallen continuously at Jamaica's Kingston Norman Manley Airport since midnight, with 1.89" having fallen from midnight to noon local time. Sustained winds of 24 mph also affected Kingston between 7am and 8am this morning. Satellite-estimated rainfall amounts of 1.4" per hour occurred in ocean regions 100 miles to the southeast of Kingston this morning, and heavy rains of up to 1/2" per hour are probably affecting portions of Jamaica early this afternoon, judging by the recent increase in heavy thunderstorm activity seen on visible satellite loops. This imagery also shows a slow increase in organization of 94L in recent hours, with spiral bands beginning to develop to the southeast of the center. There is a broad, poorly-defined circulation apparent that is not well enough defined to make 94L a tropical depression. Water vapor satellite loops show a region of dry air on the west side of 94L, and this dry air is interfering with the storm's organization. However, upper air balloon soundings from Kingston and the Cayman Islands taken at 8am EDT this morning show much moister air at mid levels of the atmosphere compared to Saturday (2% humidity at 500 mb on Saturday, compared to 49% this morning at Grand Cayman), and 94L appears to be gradually overcoming its dry air issues. Wind shear remains in the moderate range, 15 - 20 knots, and is predicted by the SHIPS model to remain below 20 knots through Tuesday morning. Water temperatures in the Central Caribbean are about 1°C above average, 28 - 28.5°C, which is 2°C above the threshold needed to support development of a tropical storm.


Figure 1. Rainfall rates of up to 1.4" per hour (pink colors) were estimated by the F-15 satellite for 94L at 6:02am EDT Jun 5, 2011.

Since 94L is so large and is battling dry air, it is taking its sweet time to develop, and today's mission by the Hurricane Hunters has been cancelled. A new mission is scheduled for Monday afternoon at 2pm EDT. This morning's 06Z model runs are pretty unimpressed with 94L, with most of them showing little or no development. At 2pm EDT on Sunday, NHC gave the disturbance a 40% of developing into a tropical depression by Tuesday. If 94L stays to the south, its chances of development are greater, since a band of very high wind shear of 30 - 50 knots lies over Cuba and the southern Bahama Islands. The disturbance is expected to meander slowly westward or northward over the next two days, with Jamaica and southeastern Cuba being the primary targets for very heavy rains of 4 - 8 inches through Tuesday. Haiti and Central Cuba can expect somewhat lesser rains of 3 - 6 inches. If 94L does develop into a tropical depression and moves northwards over Cuba by Wednesday, I don't see the storm attaining hurricane strength, due to the high wind shear. The primary threat from 94L will be very heavy rains, capable of causing life-threatening flash flooding.


Figure 2. Afternoon satellite image of the Central Caribbean disturbance 94L.

Jeff Masters

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1697. scott39
It has the most convection around the circulation, that I have seen so far.
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Quoting islander101010:

plenty of time to do what it wants


NHC discussion this morning said it will sit there until Wednesday when upper level winds become less favorable.
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Quoting Tropicsweatherpr:
Thw window for 94L to develop continues to dwindle.

plenty of time to do what it wants
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system needs to be more circular doubt if recon goes nevertheless the greater antillias is in for a good soaker
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Any chance the left hand blob is what Walshy is showing in post 1664?
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Pottery sounds idyllic. I can bring some Samsula watermelon :)
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1690. scott39
If nothing else right now...94L is definitely moistening up!
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Quoting superpete:
Morning everyone.Clear skies here on Grand Cayman just now, but some big clouds moving in, more much needed rain on the menu for today
We had a heavy rain up here about 20 min. ago. Sky still overcast.
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Quoting GeoffreyWPB:
Just updated...



...so...It's gonna go somewhere between Matamoros and Liverpool?!
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Quoting scott39:
Maybe if we talk trash about 94L, that will really tick her off and she will want to do something! Thats how I motivate the associates at work! J/K
Quoting scott39:
Maybe if we talk trash about 94L, that will really tick her off and she will want to do something! Thats how I motivate the associates at work! J/K

OK,I'll try:) 94l has 0% chance for developing,or even less.Shear is to high for it
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Quoting superpete:
Morning everyone.Clear skies here on Grand Cayman just now, but some big clouds moving in, more much needed rain on the menu for today


Good morning, yes I think somehow you will get your rain soon.
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Just updated...

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ATCF says pressure is down another notch:

AL, 94, 2011060612, , BEST, 0, 177N, 816W, 25, 1006, LO, 34, NEQ, 0, 0, 0, 0, 1010, 275, 125, 0, 0, L, 0, , 0, 0, INVEST, M,

Getting there. Slowly...
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Morning everyone.Clear skies here on Grand Cayman just now, but some big clouds moving in, more much needed rain on the menu for today
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Quoting bappit:
News from the Houston area NWS:

Climate...
the high temperature at Houston reached 105 degrees on Sunday. This is the warmest temperature ever recorded in the month of June. The previous warmest June temperature was 104 degrees established on June 24th and June 26th 2009. The earliest Houston ever recorded a temperature of 105 degrees prior to Sunday was July 26th 1954. Records for the city of Houston date back to 1891 and there have been only 15 days in which the temperature has reached or exceeded 105 degrees.

4 - 1909
1 - 1954
2 - 1962
3 - 1980
5 - 2000

New maximum temperature records (houston) have been established on four out of the first five days of June. Galveston and Houston both crushed their previous record high temperature for the day (june 5th) by seven...yes seven degrees.


Yes we are desperate for rain right now
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1681. scott39
Maybe if we talk trash about 94L, that will really tick her off and she will want to do something! Thats how I motivate the associates at work! J/K
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1680. IKE

Quoting bappit:
News from the Houston area NWS:

Climate...
the high temperature at Houston reached 105 degrees on Sunday. This is the warmest temperature ever recorded in the month of June. The previous warmest June temperature was 104 degrees established on June 24th and June 26th 2009. The earliest Houston ever recorded a temperature of 105 degrees prior to Sunday was July 26th 1954. Records for the city of Houston date back to 1891 and there have been only 15 days in which the temperature has reached or exceeded 105 degrees.

4 - 1909
1 - 1954
2 - 1962
3 - 1980
5 - 2000

New maximum temperature records (houston) have been established on four out of the first five days of June. Galveston and Houston both crushed their previous record high temperature for the day (june 5th) by seven...yes seven degrees.
Yes....I think the planet is warming. Is it reversible? Unlikely to me, but possible.

Looking at a water vapor of the GOM and western Caribbean. Easy to see the ULL in the western GOM. Time is running out on 94L. It'll wind up a sheared mess.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
1679. ncstorm
Quoting emcf30:


NC I brought that same thing up on here yesterday. Development of a system North of the Bahamas and sticking around for a few days. I think it may be something to watch out for tho its way to early to make any solid predictions.


I agree..its not like the GFS to hold onto a storm so far out..
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Miami NWS Discussion

WEDNESDAY THROUGH SUNDAY...
ALTHOUGH CONFIDENCE BEGINS TO DECREASE THIS FAR OUT INTO EXTENDED
FORECAST...THE MODELS CONTINUE TO INDICATE INCREASING DEEP LAYER
MOISTURE SPREADING NORTH OVER SOUTH FLORIDA TOWARD THE END OF THE
WEEK AS A BROAD LOW-LEVEL CIRCULATION OVER THE CARIBBEAN SLOWLY
DRIFTS WEST-NORTHWEST. DUE TO THIS LOW CONFIDENCE...WILL SLIGHTLY
INCREASE RAINFALL COVERAGE PROBABILITIES BACK TOWARD CLIMATOLOGY
THROUGH THIS PERIOD.
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Thw window for 94L to develop continues to dwindle.
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Come on already. Get it together
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1674. bappit
News from the Houston area NWS:

Climate...
the high temperature at Houston reached 105 degrees on Sunday. This is the warmest temperature ever recorded in the month of June. The previous warmest June temperature was 104 degrees established on June 24th and June 26th 2009. The earliest Houston ever recorded a temperature of 105 degrees prior to Sunday was July 26th 1954. Records for the city of Houston date back to 1891 and there have been only 15 days in which the temperature has reached or exceeded 105 degrees.

4 - 1909
1 - 1954
2 - 1962
3 - 1980
5 - 2000

New maximum temperature records (houston) have been established on four out of the first five days of June. Galveston and Houston both crushed their previous record high temperature for the day (june 5th) by seven...yes seven degrees.
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1673. emcf30
Quoting ncstorm:
Good Morning..

The latest GFS run has been consistent on a storm off the SE Atlantic coast for a while now..around the 16th..


NC I brought that same thing up on here yesterday. Development of a system North of the Bahamas and sticking around for a few days. I think it may be something to watch out for tho its way to early to make any solid predictions.
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1672. MahFL
Just west of Jamica it appears there is no shear at all.
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1671. pottery
There is a pair of Toucans making loud "cheeping" noises in the top of a tree outside.
I'm going to join them.

See you all at breakfast. Presslord is fixin' it right now...
Member Since: October 24, 2005 Posts: 0 Comments: 24307
1670. IKE
Ooops.....my bad....I'm a poor reader....

AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT MISSION HAS BEEN RESCHEDULED TO INVESTIGATE THE SYSTEM
TOMORROW...IF NECESSARY.



Member Since: June 9, 2005 Posts: 23 Comments: 37858
1669. IKE
I see why the NHC talks about "becoming unfavorable"....

48 hour shear...look at the NW Caribbean....



Member Since: June 9, 2005 Posts: 23 Comments: 37858
1668. scott39
Where did that lady go? I hear her clearing her throat! mememe--cough--cough--mememe
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1666. afj3
000
ABNT20 KNHC 061138
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON JUN 6 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A LARGE BUT DISORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH A BROAD LOW PRESSURE SYSTEM CONTINUES OVER MUCH OF
THE CENTRAL AND WESTERN CARIBBEAN SEA. THE AREA OF LOWEST PRESSURE
IS LOCATED ABOUT 130 MILES SOUTH OF GRAND CAYMAN AND REMAINS
SEPARATED FROM THE STRONGEST THUNDERSTORM ACTIVITY. HOWEVER...SOME
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT DAY OR SO
BEFORE UPPER-LEVEL WINDS BECOME UNFAVORABLE. THERE IS A MEDIUM
CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS. AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT MISSION HAS BEEN RESCHEDULED TO INVESTIGATE THE SYSTEM
TOMORROW...IF NECESSARY. REGARDLESS OF DEVELOPMENT...HEAVY RAINS
COULD CAUSE FLASH FLOODS AND MUD SLIDES OVER PORTIONS OF HAITI AND
JAMAICA AS THE SYSTEM MOVES SLOWLY TOWARD THE NORTHWEST OR NORTH
OVER THE NEXT COUPLE OF DAYS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART
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1665. IKE


Member Since: June 9, 2005 Posts: 23 Comments: 37858
1664. Walshy
Down the Road
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1663. MahFL
Quoting ncstorm:
Good Morning..

The latest GFS run has been consistent on a storm off the SE Atlantic coast for a while now..around the 16th..


Will it come to JAX as a Hurricane ? lol.
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1661. Walshy
NO RECON TODAY
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1660. ncstorm
so now the NGP got 94L doing an ernesto..the CMC got a east coast drive by..the GFS loses it but has something coming into the gulf around the 21st, GFDL has it heading for the panhandle and it looks like the ECWMF has it off the east coast of florida..talk about all over the place..
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Quoting pottery:

Sorry about that.
Kind of puts a damper on an otherwise nice day.

:):))



Lol.... lets just put it behind us.

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1658. IKE
"""THE AREA OF LOWEST PRESSURE
IS LOCATED ABOUT 130 MILES SOUTH OF GRAND CAYMAN AND REMAINS
SEPARATED FROM THE STRONGEST THUNDERSTORM ACTIVITY""".....

Another recon canceled....my guess.

0-0-0.

$$
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting NICycloneChaser:


Leaving it behind. Things certainly aren't getting better for 94L.

As I say-today is the last chance for it.Little to no chances thereafter
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The odds of 94L even becoming a tropical depression are less then 10%..I think they cancel the recon once again today...wind shear is taking its toll on 94L..Tropics are very quiet for now...
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1654. pottery
No recon today!
Member Since: October 24, 2005 Posts: 0 Comments: 24307
No change as far as the NHC is concerned then.
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Still 40% with 8 AM TWOAT
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1651. scott39
Quoting IKE:

I don't think so.


I think the odds of this becoming a TS are low.
If it has no protection and the wind shear doesnt relax...then it better make TD today. Hopefully rain will still make it to someone.
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Quoting scott39:
Is the wind shear forecasted to die down N of 94L?
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1649. pottery
Quoting earthlydragonfly:



Morning everyone... not sure I was ready for that image....

Sorry about that.
Kind of puts a damper on an otherwise nice day.

:):))
Member Since: October 24, 2005 Posts: 0 Comments: 24307
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON JUN 6 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A LARGE BUT DISORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH A BROAD LOW PRESSURE SYSTEM CONTINUES OVER MUCH OF
THE CENTRAL AND WESTERN CARIBBEAN SEA. THE AREA OF LOWEST PRESSURE
IS LOCATED ABOUT 130 MILES SOUTH OF GRAND CAYMAN AND REMAINS
SEPARATED FROM THE STRONGEST THUNDERSTORM ACTIVITY. HOWEVER...SOME
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT DAY OR SO
BEFORE UPPER-LEVEL WINDS BECOME UNFAVORABLE. THERE IS A MEDIUM
CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS. AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT MISSION HAS BEEN RESCHEDULED TO INVESTIGATE THE SYSTEM
TOMORROW...IF NECESSARY. REGARDLESS OF DEVELOPMENT...HEAVY RAINS
COULD CAUSE FLASH FLOODS AND MUD SLIDES OVER PORTIONS OF HAITI AND
JAMAICA AS THE SYSTEM MOVES SLOWLY TOWARD THE NORTHWEST OR NORTH
OVER THE NEXT COUPLE OF DAYS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
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Quoting TexasGulf:
A nice storm cell moved through Kingwood, Texas (NE of Houston) about 7:00pm. We just got power restored about 10:00pm.

There was some marble sized hail and about 1" of welcome rain in the span of 1/2 an hour. The wind was outrageous, though. Wind gusts at a neighborhood level were every bit as high as those I saw in the eye-wall of Hurricane Ike. My rough guesstimate would be winds in the 70-80 mph range, pretty much constant for about 15-minutes. Several trees went down in the neighborhood, trash cans blowing down the street... the usual stuff. It was quite a powerful little storm cell. At one point, from the swirling and change in wind direction, I could swear it was trying to produce a vortex.

Anyway, that was impressive for such a small, isolated storm cell.


By the time it hit Spring, it had died down a little. Lots of straight line gusts (some branches down, etc) and rain for about 30 minutes which I am very grateful for. We did not lose power though we did earlier in the day when the storms were well away from us.
I would estimate 1/4 inch of rain. After yesterdays 105 degree high it was a welcome relief.
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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.