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
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cmc is crazy
Yeah, going to do that soon.
ha! Seems appropriate considering we have no idea if a new circulation is cooking underneath the convection.
This is basically what I saw before I left this p.m..... the area of low pressure was still too broad to allow any serious development. It really needs to tighten up tonight if it's going to get going anytime soon.
Are models still not putting 94L N of Cuba before the end of the week?
I think that they don't know what to do so they just left it at 40% I think they know about reformation of the COC but they want to wait for convection to increase and for them to get the first vis sat image and also that the old COC is nearly dead in the water
There is no concrete proof that a new LLC exists, I guess that's why they kept the circle with the old LLC. If by tomorrow it becomes evident a new circulation formed they will then move the circle and up the probability.
Tropical Cyclone Outlook
11:00 PM PDT June 5 2011
==================================
Satellite images during the past few hours indicate that the area of disturbed weather centered about 450 miles south of Acapulco, Mexico has changed little in organization. However, environmental conditions remains very favorable for development.
Tropical Cyclone Formation Potential
======================================
There is a HIGH chance of this disturbance to form into a tropical cyclone within the next 48 hours
wow
Pretty rare to see rain in June, but thanks to that cut off low sitting off of central California, were getting a few showers. Sierra Nevadas are likely getting some more snow on the 8000 ft plus peeks which is really out of season and is coming in addition to what is already a record year in terms of snow for the entire mountain range as well much of the Rooky mountains
The what? :)
Shear on the up, unfortunately for 94L. Anti-cylcone aloft is moving away from 94L.
If indeed that convection isn't the signification of a possible center reformation, then I think it's safe to bid adieu to 94L.
People are going off of the visual circulation of cloud tops. They are not going off what of the lower level winds.
I've been following the low cloud motions all evening. There is still a broad circulation in that vicinity, I agree. But it appears to be quite diffuse and is losing its luster. Whereas there was evidence of weak cyclonic banding in the vicinity of the mid-level circulation several hours ago.
If I am indeed incorrect in my thinking, I will be the first to admit it.
Also, the decending ASCAT pass shows no sign of a previous LLC...
But I have been wrong once before...
In any case, I think the NHC will go ahead with the afternoon recon flight.
Tropical Cyclone Outlook
11:30 AM IST June 6 2011
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Bay Of Bengal
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Broken intense to very intense convection over Bay of Bengal south of 11.0N east of 83.0E and between 12.5N to 15.5N and 82.5E to 91.0E, northeast Andaman Sea. Broken low/medium clouds with embedded moderate to intense convection over northeast Bay of Bengal and Arkan coast and rest Bay of Bengal south of 18.0N east of 83.0E, gulf of Martaban, Tenasserim coast, and rest Andaman Sea.
Arabian Sea
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Low level circulation over Arabian Sea off Maharastra coast has intensified into a low pressure area over central and adjoining northeast Arabian Sea. The vortex is the INSAT imagery is centered near 19.0N 71.5E with Dvorak intensity of 1.0. The chance of this low pressure to intensify further into a depression during the next 24 hours is MODERATE.
Associated broken intense to very intense convection over Arabian Sea (Cloud Top Temperatures -80C) north of 12.5N east of 68.0E and adjoining exterior south Guj and adjoining Gulf of Cambay.
If you look carefully, you can see a slight curvature of the wind barbs at about 77.8W, 15.8N, that could be the infamous LLC. I don't think that LLC is nearly as well defined as a lot of others do though.
Mornin Ylee....Hope u not workin too hard!!
I see Ike has a high temp of 102º today, so ya'll go easy on him.
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