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No change to Caribbean disturbance

By: Dr. Jeff Masters, 12:05 AM GMT on September 27, 2005

The tropical disturbance in the central Caribbean sea, south of Hispanolia, has changed little this afternoon, and remains very disorganized. There is no surface circulation, and pressures are not falling significantly. This disturbance split in two this morning, and the leading (westernmost) portion was effectively destroyed by wind shear associated with an upper level low to its northwest. The trailing (eastern) portion of the disturbance south of Hisponolia has about 10 knots of shear over it, which is marginal for tropical storm development.

The upper level low is moving to the north away from the disturbance, and a favorable low-shear environment is forecast to set up over the disturbance by Wednesday or Thursday. A reconnaissance airplane is scheduled to visit the area on Tuesday, but I doubt it will be needed until Wednesday. I still give this disturbance a 60% chance of becoming a tropical storm by Friday, when it should be near western Cuba or in the Gulf of Mexico. It is far too early to even offer even an educated guess about what might happen then.



Mid-Atlantic disturbance
A tropical disturbance located about 1000 miles east of the Lesser Antilles has effectively been destroyed by wind shear imparted by a large upper-level low pressure system to its west. Development of this disturbance is not expected. The ITCZ is very active in the region extending from the African coast westwards for 1000 miles. Tropical storm development along this area is possible later this week.

Elsewhere in the tropics
A cluster of thunderstorms accosiated with the tail end of the cold front that pulled Rita northeast across the U.S. is now emerging over the northern Gulf of Mexico, near the Florida Panhandle. Strong upper levels winds should prevent any development in this area for at least the next two days.

Alaska and Hawaii
We don't talk much about these states in my tropical blog, but Nome, Alaska had a huge mid-latitude cyclone hit them Friday. The storm brought sustained tropical storm force winds gusting to 52 mph, a 10-foot storm surge, and a pressure of 972 mb! This was in essence a Category 1 hurricane, as far as the storm surge and pressure go. Thanks to wunderphotographer Destiny, who brought this newspaper article to my attention.

Hawaii has its second tropical system of the season to be concerned with. Hawaii dodged major Hurricane Jova last week, andTropical Storm Kenneth is expected to pass within 100 miles of the Islands by the end of the week. Kenneth should only be a tropical depression by then, and bring a few extra rain showers to the islands.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.