Disturbance 94L in Central Atlantic; NHC management changes
A tropical wave midway between Africa and the Lesser Antilles (labeled "invest 94L" by NHC this morning) has become a little better organized this morning, and does have the potential to develop into a tropical depression later this week. Wind shear is a favorable 5-10 knots over 94L, and shear should not be a problem for it over the next few days. The system is not well-organized, with a sloppy, elongated circulation, as seen on last night's QuikSCAT pass. This morning's QuikSCAT pass missed the storm. The system does have a major impediment to development--the presence of a large, dusty area of dry air surrounding its north side (Figure 1). Water vapor satellite loops of the region don't show any significant moistening of the region around 94L occurring, and this will have to happen before the system can develop into a tropical depression. If the storm can develop a better-organized circulation, it will be able to pump more moisture into the surrounding atmosphere and help itself out. Current visible satellite loops shows that this is not happening at present--the thunderstorm activity associated with 94L is rather weak.
None of the reliable computer models develop 94L. The system should track through the Lesser Antilles Islands on Friday, bringing gusty winds and heavy rain. I expect that the earliest 94L could become a tropical depression would be Thursday, and it is unlikely the Lesser Antilles would experience anything worse than a 50 mph tropical storm. It is more likely that 94L will still be a tropical disturbance when it passes through the Lesser Antilles.
Figure 1. Water vapor satellite image of the Central Atlantic from 8:15am EDT 8/28/07. The brown colors denote very dry and dusty air from the Saharan Desert.
Honduras disturbance
A westward-moving tropical wave is bringing heavy rains to Honduras and Nicaragua today. Due to its close proximity to land, development of this wave into a tropical depression is not expected. The wave is under 10-15 knots of wind shear. None of the reliable models are predicting that this system will develop.
Computer model update
The UKMET and GFS models are indicating the possible development of a tropical depression by Thursday or Friday off the coast of Africa. There is a large surge of moisture with at least one strong tropical wave embedded in it coming off the coast of Africa this week. This moister air should make a more favorable environment for a tropical depression to form in than the one 94L finds itself in.
Most of the models also predict a low pressure system will develop off the North Carolina coast along an old frontal boundary on Thursday. Such a development may be an ordinary extratropical low pressure system, but could make the transition to a tropical system if the shear drops low enough.
NHC management changes
Acting director Dr. Ed Rappaport of The National Hurricane Center (NHC) will continue on the job until the end of this hurricane season, NOAA management revealed yesterday. Rappaport replaced director Bill Proenza on July 9, following an extraordinary few months of tumult at NHC. Joining the NHC staff on September 4 will be a new interim deputy director--Bill Read, who currently serves as the meteorologist in charge of the National Weather Service's Houston-Galveston office. Deputy director was the post Rappaport held prior to July 9. Bill Read applied for the directorship of NHC when Max Mayfield retired, but was not awarded the job. His arrival at NHC during the peak of hurricane season will be a welcome addition, as he has considerable experience dealing with hurricane emergencies.
In an apparent effort to follow some of the management changes recommended by the independent review team that performed the snap inspection of NHC in early July (see Attachment 9 of the Senate testimony from July), a new manager of the ten hurricane forecasters has been appointed as well. Rick Knabb, who is one of the six senior hurricane specialists, will be the new manager, and will be Rappaport's backup for TV interviews during hurricane emergencies.
It is still undecided where former director Proenza will wind up, but the chairs of two Senate subcommittees investigating the matter have recommended that Proenza be returned to his former job as head the NWS Southern Region.
Next update
Tomorrow is the 2-year anniversary of Hurricane Katrina. I'll discuss my experience with blogging about the storm, and give an update on 94L and the rest of the tropics.
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 — Blog Index
I agree with taz in regards to 94l and totally disagree with him in regards to the wave in the Carribean(it is heading W)
Eye, you cannot say it will poof, as it is doing exactly what it did last night.
like hello the Carribean wave is not heading it is heading N
Taz, the NHC is saying it is heading west. Is there a more northerly component? I believe so. the nhc is the experts, not any of us here. the wave appears to be moving more north due to the SW shear (shear maps show the little pink arrows hitting it from the SW)
The good thing is, the GFS and Euro have been more aggressive with depicting TC developing beyond Day 7 or so. Although there isn't the type of run to run consistency like there was with Dean, it probably is a sign that activity will pick up as we head into Early September. As far as Cape Verde systems are concerned, the window of opportunity for US strikes is closing quickly, with the chances of a CV storm hitting the US dropping markedly if the formation date is after early September. So for you CV US-hit fans out there, the next 2 weeks will be crucial.
1) ALL the models pick it up
2) NONE of the models pick it up.
Its when only a few do that it usually doesnt happen. Kinda odd I guess.
Someone can correct me if I am remembering incorrectly.
Also, what is the difference between the FSU model A, and the FSU model B? Does anyone know?
By reading some of the post during Dean and Florence and many others, too numerous to mention, disturbances, TS, and hurricanes are attraced to the GOM or FL. I dont know why?
b)no sfc low
c)NHC are experts. Taz, you seem to use the NHC for their TWD when you point out areas of disturbed weather. But, when they disagree with you, you claim they dont know what they are talking about
wow taz
Caribbean blob may form, but it is close to land right now. Not saying it won't....just keep watching it for us okay? Thanks.
I think the NHC is correct. The wave in the Carribean is moving West.
no its moveing N
By the way...I love how some of the people on TWC pronounce Comp"eeche" as Camp"pache"....
based on this, it almost has to move into Belize
that a SFC map and that map wont tell you any thing at all
Winds currently east. Still not a good night for a dinghy ride.
img src="
Viewing: 851 - 901
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 — Blog Index