Wednesday, September 01, 2010

Hurricane Earl, Tropical Storm Fiona and Tropical Storm Gaston - 012100Z





Hurricane Earl is tracking towards the northwest at about 15 knots. At present the outer edges of the wind field are just east of Abaco in the Bahamas. Maximum sustained winds are about 115 knots (213 kmh/132 mph). Hurricane warnings have been issued for the North Carolina coast. Conditions suggest that Earl will restrengthen to category 4, possibly by later today. The coastal area under a Hurricane Warning can expect a destructive storm surge in the range of 3 to 5 feet above ground level. The swells being generated ahead of Earl have already started to reach the Bahamas as can be seen on this Abaco webcam. Large swells will begin to hit the US east coast shortly.

As Earl reaches the edge of the subtropical ridge it should start recurving more to the north-northwest and then north, possibly as early as tonight. As Earl encounters the Westerlies it should start to turn out towards the east by Friday morning. All the models seem to support this and the NHC is issuing that guidance. Earl should weaken in intensity but increase the speed of its advance as it encounters greater wind shear. If there's a problem it is the record warm waters it will encounter as it leaves the tropics. The Gulf Stream is certainly warmer than it has ever been and it is providing enough sea surface temperature to support a hurricane.

Models produce a small westward adjustment of Earl's track. That continues to suggest that Earl will make landfall somewhere between Maine and the South Shore of Nova Scotia, most likely with Tropical Storm force. (This could create a massive surge in the Bay of Fundy.)

TS Fiona is a small Tropical Storm with sustained winds of 50 knots (93 kmh/58 mph). The cyclone is showing tropical storm force winds with a radius of only 100 miles around it.

Fiona is tracking towards the northwest at about 17 knots. That's still pretty fast and most models suggest that Fiona will continue in that direction but begin to slow significantly. Intensity at this point is a touch call, however, the cyclone should be influenced by Earl in the next two days which should put the cyclone into the decay stage.

TS Gaston is in the centre of the tropical Atlantic moving slightly north of westward at 13 knots. Initial intensity is sustained winds of 35 knots (65 kmh/40 mph). Gaston will encounter a couple of conditions which will challenge development: There is a considerable amount of dry air to the west and north of it; and, the weakening subtropical ridge will cause it to slow. Most models show Gaston becoming a hurricane within the next 5 days.


As always, click any image to enlarge.

Added: A look at the Atlantic this evening with the named storms identified.


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