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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1047. Levi32
Quoting beell:


Based on the wind barbs, they don't look that much different. Stronger in the model.


I'd say stronger on the GOES analysis, based on the fact that the GFS has not a single east, northeast, or northerly wind barb on that image. The upper low seems more closed on satellite, though there is some uncertainty since it would be more defined the lower you go, until about 500mb.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
i dont think there will be any landfalling hurricanes this year
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It looks like 94L is going to drift into the gulf.
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1044. aquak9
WUBA is still alive. We didn't go underground...we float.
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1042. Levi32
Deep-layer moisture showing up at Cancun today:

Member Since: November 24, 2005 Posts: 635 Comments: 26700
1040. Patrap
..."take my hand child and come with me,.and to a castle I will take you"...
Member Since: July 3, 2005 Posts: 428 Comments: 129844
1039. beell
Quoting Levi32:
Anyone else notice how most of the models forecasts (GFS here for example) show this configuration of the 200mb trough in the Gulf of Mexico for 0z (10 minutes from now), yet the GOES upper winds analysis shows the trough much farther southwest and still more dug in and amplified than the models show.

18z GFS 6-hour 200mb forecast:



22:30z GOES WV upper winds analysis:




Based on the wind barbs, they don't look that much different. Stronger in the model.
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i dont think 94L is going to develop
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Meanwhile....a wee bit closer to home....blogger "sunlinepr" here on our friendly little chat room, posted an interesting satellite pic of the west coast (see post # 821). With that low off the west coast, basically stuck in place, and the front coming in from the NW squeezing the atmosphere, I would imagine A LOT of rain landing on the Sierra Nevadas, Cascades, etc. Mix in some warm temperatures and a RECORD SNOW PACK, and you have a recipe for some truly catastrophic flooding.
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1036. Levi32
Quoting NICycloneChaser:


What impact could this have for 94L?


I'm not sure. I'm still trying to verify whether there is actually an initialization issue. The GOES winds analysis consists of several levels, some of them below 200mb. the GFS does show the trough more amplified down at 300mb and 500mb, but still not as far as water vapor imagery and GOES high-density winds show.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
Quoting CybrTeddy:


2009 had 9, 2006 had 10. 2009 should have had 10 though, there was a system in May that clearly developed into a Tropical Storm but that was a long time ago.


Try not to start the 'what should have been named debate'.... Lol
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting KEEPEROFTHEGATE:
here is what i have


Thanks
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1033. pottery
Quoting Chicklit:
Evening guys.
LinkSWLoop

17N 77W?

That's what I see too.
But the LLC is closer to 16.5n and 80.2w, from all reports. And that is the Official Center of the system.
Looking at all the Loops, I see it where you see it, but that's only in the Mid and Upper levels apparently.
Member Since: October 24, 2005 Posts: 0 Comments: 24883
Quoting Tazmanian:



i think 06 and 09 where this about the same


2009 had 9, 2006 had 10. 2009 should have had 10 though, there was a system in May that clearly developed into a Tropical Storm but that was a long time ago.
Member Since: July 8, 2005 Posts: 259 Comments: 24575
Quoting Levi32:
Anyone else notice how most of the models forecasts (GFS here for example) show this configuration of the 200mb trough in the Gulf of Mexico for 0z (10 minutes from now), yet the GOES upper winds analysis shows the trough much farther southwest and still more dug in and amplified than the models show.

18z GFS 6-hour 200mb forecast:



22:30z GOES WV upper winds analysis:




What impact could this have for 94L?
Member Since: August 10, 2010 Posts: 2 Comments: 1971
oh this is interesting hey guys I was just lookin at the RGB sat loop and I noticed that east of all the heavy convection near South of 20N between 70-75W I am seeing some of the Mid-lower level clouds strting to wrap into the Mid Level Circulation instead of going all the way around showing a broad circulation going into the weak one near 79/80W this could mean that a LLC is developing under the Mid but however not closed, anyway this is what I am seeing on that side
Member Since: June 13, 2009 Posts: 2 Comments: 12716
1028. Levi32
Anyone else notice how most of the models forecasts (GFS here for example) show this configuration of the 200mb trough in the Gulf of Mexico for 0z (10 minutes from now), yet the GOES upper winds analysis shows the trough much farther southwest and still more dug in and amplified than the models show.

18z GFS 6-hour 200mb forecast:



22:30z GOES WV upper winds analysis:


Member Since: November 24, 2005 Posts: 635 Comments: 26700
1027. txjac
Quoting NICycloneChaser:


Wow, that's pretty impressive.


Impressive and scary
Member Since: April 24, 2010 Posts: 1 Comments: 2617
In doing so, scientists hope to start working their way toward an answer to the ultimate question: Why nature favored matter over antimatter at the creation of the universe, even though the two should have been fashioned in equal amounts (and subsequently annihilated each other, we suppose). They didn't, which violated CPT symmetry, or the position that particle charges, parities, and time flows should not be predisposed in one direction or another. In our universe, for example, positive charges favor heavy particles, matter is favored over antimatter, and forward time is favored over reverse.

rain, rain go away - come again another day...........................



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Quoting clwstmchasr:
So reading the TWO, even if 94L develops overnight, conditions will not allow it to develop starting tomorrow night. Typical for June, wind shear is usually a system killer.


It's difficult to know what exactly the NHC means though, when they say 'less favorable' they don't necessarily mean hostile, but just that it won't be able to get started. If it does get well organised tomorrow, might be able to hold it's own against the shear. If higher shear does arrive tomorrow evening though, I'd have doubts about development.
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting texwarhawk:


Here in SW Houston, got about 1/3 of an inch, a little to the west of here they got 2+ inches near Fulshear.


Hope you get lots more than that amount of rain over the next few days into a week or so.
863. galvestonhurricane Told us how bad you were having it with the heat earlier tonight, I sure hope you get some relief soon.
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1023. Patrap
...indeed
Member Since: July 3, 2005 Posts: 428 Comments: 129844
Evening guys.
LinkSWLoop

17N 77W?
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Quoting NICycloneChaser:


Gotta remember that 09 wasn't far off the long term average, despite having much less activity than most of the past 15 years.



i think 06 and 09 where this about the same
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Quoting Patrap:
CERN Scientists Trap Antimatter for Almost 17 Minutes


Wow, that's pretty impressive.
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting Tazmanian:
this year may be more like 09


Gotta remember that 09 wasn't far off the long term average, despite having much less activity than most of the past 15 years.
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting DontAnnoyMe:


LOL, but there are some who hope that's what happens ;-)



cool
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1016. Patrap
CERN Scientists Trap Antimatter for Almost 17 Minutes
Member Since: July 3, 2005 Posts: 428 Comments: 129844
this year may be more like 09
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Quoting Tazmanian:
hurricane season a bust


LOL, but there are some who hope that's what happens ;-)
Member Since: September 21, 2010 Posts: 1 Comments: 3690
Quoting NICycloneChaser:


Not sure whether to laugh or groan....



LOL
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91E has a better ch
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Quoting Tazmanian:
hurricane season a bust


Not sure whether to laugh or groan....
Member Since: August 10, 2010 Posts: 2 Comments: 1971
1009. xcool
lol
Member Since: September 26, 2009 Posts: 2 Comments: 15684
94L RIP
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hurricane season a bust
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1. SHOWER AND THUNDERSTORM ACTIVITY HAS CHANGED LITTLE OVER THE PAST
FEW HOURS IN ASSOCIATION WITH A BROAD LOW PRESSURE SYSTEM LOCATED
ABOUT 175 MILES WEST-SOUTHWEST OF JAMAICA. WHILE THE SHOWER AND
THUNDERSTORM ACTIVITY REMAINS CONCENTRATED MAINLY TO THE EAST OF
THE AREA OF LOWEST SURFACE PRESSURES...SOME GRADUAL DEVELOPMENT OF
THIS LARGE DISTURBANCE IS POSSIBLE DURING THE NEXT DAY OR SO BEFORE
UPPER-LEVEL WINDS BECOME LESS FAVORABLE. 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
IS SCHEDULED TO INVESTIGATE THE SYSTEM MONDAY AFTERNOON...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.

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40% you guys

holding it's own
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1004. Patrap

94L Floater - RGB Color Infrared Loop
Member Since: July 3, 2005 Posts: 428 Comments: 129844
Quoting Mrsenseofhumor:


What's for dinner?


Probably Italian tonight LOL

Member Since: August 19, 2006 Posts: 0 Comments: 15948
Quoting Drakoen:




Hey! All is well. Just thought I would drop by and post, since things are starting to pick up int the tropics.


Hey Drak! Great to see you back on here! Invest 94L is a persistent little cuss, eh? Glad to hear all is well with you. You gonna be here regularly during the season?
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Quoting PcolaDan:
Houston area may get their rain.


Here in SW Houston, got about 1/3 of an inch, a little to the west of here they got 2+ inches near Fulshear.
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I am off for dinner now. Will be back for a bit later.
Member Since: August 19, 2006 Posts: 0 Comments: 15948
Quoting Drakoen:

 lol yes. FSU is a great school and a lot of notable people have graduated from there and lead successful careers.


Ha, yeah. Strangely the first thing that comes to mind about my time at FSU is... all the fun I had! Then again, I didn't major in math intensive subjects so my weekends were clear. But for sure, since graduation its been a downhill slope with regards to having "fun." Man oh man I miss fsu life !
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Quoting Seflhurricane:
so the upper level winds are expected to become hostile soon ??? HMMMMM


Tomorrow will be it's best chance, kind of make or break.
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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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