Update, Thursday - November 10, 11:15PM EST
Tropical Storm Sean is beginning to suffer structural decay with winds likely down to about 55mph as windshear has separated the low level center from the mid level center. The weakening trend should continue on Friday as Sean passes northwest of Bermuda and gets absorbed by a cold front approaching from the west later on Friday. Tropical Storm force winds are still likely over Bermuda Friday morning along with one or two inches of rain. At 11/04Z, winds at Hamilton were gusting to 43mph.
Update, Wednesday - November 9, 6PM EST
Sean is a strong Tropical Storm with sustained winds of 65mph and some additional intensification is possible but the window of time for that intensification is shrinking. Sean started a northward movement today and a more northeasterly motion is likely later on Thursday. Strong southwesterly windshear ahead of a cold front moving off the Atlantic coast along with SSTs of 24C will begin to weaken Sean later Thursday afternoon. There is a chance that Sean will reach hurricane strength before the weakening process begins and in fact NHC now indicates that, but the models are not as aggressive with intensification. There is a likely probability of tropical storm force winds in Bermuda late Thursday evening as Sean passes west of the island and a Tropical Storm Warning remains in effect for Bermuda.
Bermuda Weather Reports
Bermuda Weather Radar
Update, Tuesday - November 8, 1:30PM EST
This is an update to note that as Sean has continued to acquire more tropical characteristics, NHC has elected to classify him now as Tropical Storm Sean.
With this transition into a more completely tropical than non-tropical cyclone, winds and convection associated with the cyclone are pulling in towards its center of circulation, and the window for Sean to become a strong TS or minimal hurricane is now open this week. Still, for now, the official forecast calls for a low-mid range storm, only.
Update, Tuesday - November 8, 5:00AM EST
Invest 98L is now Subtropical Storm Sean, with maximum sustained winds of 45MPH.
Sean continues to hold up about stationary over waters that are plenty warm for further development, and Sean may very well transition into a Tropical Cyclone this week before being overtaken by or pushed out to cool waters by an approaching front. Given the warm waters and improving structure, it is possible that Sean becomes a Tropical Storm within twenty-four hours, and already Sean has at the very least a shallow warm core.
Sean is expected to gradually turn to the northwest, and then accelerate to the north-northeast, and is not expected to pose a direct threat to the east coast, although Bermuda may end up in its path. As for intensity, the official forecast basically keeps Sean steady-state, even as a Tropical Storm, but with time there is a chance that Sean intensifies a good bit more - possibly even becoming a shallow hurricane.
Update, Tuesday - November 8, 12:15AM EST
Invest 98L continues to churn about 650 miles east of east central Florida. At 08/05Z the center was located at 27.0N 69.7W moving to the south southwest at 4 knots. There has been slowly developing convection closer to the center earlier on Monday however the structure hasn't changed much in the past few hours. NHC has assigned a high probability (currently 70%) that Invest 98L could become a subtropical cyclone in the next couple of days.
Also worth noting is Invest 99L which is a subtropical cyclone in the Mediterranean Sea (being tracked by SSD as M01) located near 41N 6E at 08/04Z.
Update, Sunday - November 6, 9:20AM EST
Invest 98L is a stationary gale center located about 700 miles east of Melbourne, Florida, with considerable dry air to the south of the large system. Sustained winds are at 45 knots and the central pressure is 1005MB. Rough seas, rip currents and brisk northeasterly winds will exist along the Florida east coast and the northern Bahamas this week. Convection is displaced to the northeast of the center and there is only a small chance for the gale to acquire subtropical characteristics as the center drifts to the southeast.
Original Post, Sunday - October 30, 7:25AM EDST
Rina decoupled and fell apart but the convection soaked the southern half of the Florida peninsula. The basin is currently quiet and it probably will stay that way. It was certainly a busy season with one name - Irene - likely to be retired. With consideration for the un-named (Subtropical) Storm of October 8th along the coast of east central Florida - and with the possibility that this storm will be added during seasonal post analysis - the totals for the year currently stand at 18/6/3. If the un-named storm is not added, it will be the first year that has ever recorded 17 named storms. 2011 is also the first recorded season that started with 8 straight Tropical Storms or had 8 straight Tropical Storms at any time during the season.
Right now, strong westerly windshear dominates the tropical Atlantic and the hostile environment for development suggests that November will not see any additional tropical activity, but we'll check from time to time - just in case.