Caribbean disturbance 94L dumping heavy rains on Jamaica
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
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 — Blog Index
There will be. It looks like the A/B High will shift west causing more landfalling hurricanes.
Why's there blue in the BOC? I don't see anything there.
Post 1051.
That shows the Highest Probability just south of Jamaica, at around 75w-77w. Certainly not at 80+w.
Why ?
As the orbit of your hips
Eclipse
You elevate my soul..
Not sure if I follow you there. Sticking to the 200mb level, plenty of NE winds on the NE side. Trough axis on both extend from near the Mississippi coast to the coast in the BOC. Pretty good model representation for me.
I see no northeast or straight northerly winds over the Gulf of Mexico here.
because they think that the LLC may reform under the MLC
Good observation.
Looks so, doesnt it ?
Compare : GFS Trop Atl 144hrs
It's not much of a steering trough here. Its influence mainly has to do with upper-level conditions over 94L. I'm just pondering whether the model actually captures the current depth of the trough over the southern gulf or not. It may not be a big issue, but it still looks a little different.
Still no rain for us in Friendswood, TX.
Really?
Confirm that please Cayman.
Yeah, good call Nostradamus.
AL, 94, 2011060600, , BEST, 0, 169N, 801W, 25, 1007, DB, 34, NEQ, 0, 0, 0, 0, 1010, 275, 175, 0, 0, L, 0, , 0, 0, INVEST, M,
91E should be in the same position as 94l. 90% means that the system shouldn't crumble under dmin, for its able to maintain convection on its own.
I did mention that. There are a handful of wind barbs to compare that are nearly opposite of what the GFS shows, but it would be nice to have a bigger cluster to be sure. It's not a significant issue though.
AL, 94, 2011060600, , BEST, 0, 169N, 801W, 25, 1007, DB
Link
wicked the winds and water was
The Cities awashed in seas
the noble one sends the Mighty fleet'
Too weak?
Ok, I was looking at to the NE not from. My bad. Sat winds may be seeing the NE flow around the ridge whereas the model is not
There was also a weak disturbance moving along the LA coast today along the ridge with a little buckle at 500mb
All in all though. Not a big difference.
MESOSCALE DISCUSSION 1099
NWS STORM PREDICTION CENTER NORMAN OK
1101 AM CDT SUN JUN 05 2011
AREAS AFFECTED...SRN LA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 051601Z - 051730Z
...SLIGHT RISK WILL BE ADDED TO SRN LA AT 1630Z OUTLOOK...
LATEST SATELLITE AND DIAGNOSTIC DATA CONFIRM A WEAK CIRCULATION HAS
DRIFTED TO NEAR THE SERN LA COAST...MOVING WWD AT ROUGHLY 15KT.
STRONG HEATING ALONG THE WRN/SRN PERIPHERY OF THIS LOW PRESSURE
SYSTEM IS ENHANCING INSTABILITY ACROSS SRN LA SUCH THAT STRONG
STORMS ARE BEGINNING TO EVOLVE ALONG LEADING EDGE OF WWD-MOVING
CLOUD CANOPY. WITH TEMPERATURES WARMING WELL INTO THE 90S IT WOULD
SEEM LIKELY THAT A FEW OF THESE WEAKLY SHEARED UPDRAFTS COULD POSE
AT LEAST A RISK OF LOCALLY STRONG DOWNBURSTS GIVEN THAT VERY HIGH
PWAT...APPROACHING 2 INCHES...EXISTS INVOF THIS SYSTEM.
..DARROW.. 06/05/2011
Exactly. Dr. Gray (I believe it was) put South Florida's odds of getting hit by a hurricane close to 50/50, according to the Storm Prep Guide given by the Palm Beach Post.
I think this is going to happen it will reform under the MLC then we shall see an increase in convection and by sunrise convection should be blowing like nukes and if this continues then TD by 2pm or 8 pm
Apparently.
One step at a time, let's see what happens with the circulations first.
Yeah, it's not. I just try to pick up on those things because upper-level lows are one of those features that the models handle poorest, and that can have an influence on forecasts for tropical systems.
Well it sure is looking a little anaemic around 17n 80w right now, where the LLC is officially placed.
Strange stuff.
Different directions. Like I said, the satellite shows an elongated closed upper low with east, northeast, and northerly winds around it. The GFS shows a fully open trough with only northwest, west, and southwest winds.
I think a lot of people said that last year was going to be like 2004 and we all know what didn't happen.
Viewing: 1051 - 1101
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 — Blog Index