Upper level air-steam disruption protecting the US Gulf
General overview 1500z 25th September 2013 from west to east
Upper level air-steam disruption is today producing a cloud map which is messier than my daughter's bedroom floor. This is proving a very effective barrier against cyclone development but as we explained yesterday, rapid changes may produce rapid opportunities and the sea below is still storm-warm. To continue the bedroom analogy, it is still possible that heated rollers under a pile of dumped clothing could produce a sudden snag.
A remnant of disturbance fifty five merged with a frontal system over the Gulf of Mexico and produced a low pressure area in the northeastern Gulf yesterday. That system is now east of Florida, moving east-nor'east at 10 knots. This is expected to strengthen and move into the central Atlantic as a non-tropical low pressure system over the next few days however, tropical development is not expected.
A second low is expected to form east of northern Florida over the next couple of days, then strengthen and move northward as an extratropical low pressure system over the weekend and early next week. There is some debate over the exact path it will take but most guidance indicates it will track to the north-nor'east or north east, in the general direction of Nova Scotia and Newfoundland. It could pass close enough to the U.S. East Coast to bring gusty winds and widespread rainfall from the Carolinas into northern New England, however tropical development is not expected here either.
A third cell is appearing in the Gulf of Mexico but again, a rather battered one on the tail end of a front. This low is surrounded by dry air and tropical development is not expected. It should move to the east-nor'east and dissipate over the next couple of days. A few thunderstorms with locally gusty winds remain possible.
Disturbance fifty six is just to the west of the mid-Atlantic point and moving west at 12 knots. There has been little change over the past 24 hours. And unfavourable atmospheric conditions will inhibit any tropical development.
Disturbance fifty-seven is now two days west of the Cape Verde Islands and is moving west-nor'west at 10 knots. To round up a disappointing daily report, this system is expected to weaken over the next day or two then dissipate in 3-5 days.