It appears the area of disturbed weather off the north coast of Florida (99L) continue to show more signs of organization. This is being watched by the NHC for possible tropical or sub-tropical development.
Dr. Jeff Masters has a good post on some of the large scale features impacting the development of 99l.
Strong upper level winds from the west are creating about 20 knots of wind shear over 99L, and satellite loops show that these winds are keeping all of 99L’s heavy thunderstorm activity pushed over to the southeast quadrant of the storm. This shear is forecast to remain between 15 and 25 knots over the next five days by the GFS model, so any development of 99L should be slow. Despite the relatively high shear, the computer models are mostly calling for 99L to develop. Steering currents are weak in the region, and the models agree that 99L is likely to make a clockwise loop over the next three days, then potentially threaten (take your pick):
UKMET: North Carolina on Saturday
NOGAPS: Florida on Friday
HWRF: New York on Saturday
ECMWF: South Carolina on Friday
Canadian: North Carolina on SaturdayThe Hurricane Hunters are scheduled to investigate this system at 4pm EDT Wednesday.
Here some of the model information I have found both valid for Saturday Evening, September 8th. (00Z 07/09/09):
From the 12Z 070904 run of the GFS Model: Click here for the latest animation of the GFS.
(Graphic from AccuWeather.com Professional Site)
From the 00Z 070904 run of the ECMWF (EURO) Model:
(Graphic from AccuWeather.com Professional Site)
For more computer model information:
NCEP Model Analyses and Forecasts (You can find the GFS, NAM and other model data) |Tropical Cyclone Model Guidance | Experimental forecast Tropical Cyclones | Penn State e-WALL | ECMWF Model Forecasts from Unisys |
Stumble it!
1 response so far ↓
1 SteveSadlov // Sep 4, 2007 at 9:08 pm
There seems to be a gap in the operational definitions used by the NHC. The gap has to do with mid latitude cyclones, which are typically formed this time of year over the north Pacific, then are carried across the continent by the polar jet. Ejected out of the Atlantic, they may get cut off and begin to slide south. Becalmed on the West side of the Bermuda High, they temporarily become stationary over the Gulf Stream. Just what should they be called? Are they really TC’s? Or should that designation be reserved for features of Easterly Wave origin? Someone needs to get the community together and decide this once and for all, write down an agreed to global operational definitiion and stick to it. Currently, there is a grey area.
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