Wild William Wanes, Waxes Hurricane Bill Fluctuates in Strength, Threatens Bermuda, Maritimes

After having reached Category 4 with maximum winds of 135 mph, Hurricane Bill weakened to as low as 120 mph this morning and is now back up to 125 mph. The storm continues on a path which should take it between the East Coast of the U.S. and Bermuda, then close to Nova Scotia and Newfoundland. At 5 pm, the Bermuda Weather Service upgraded its Tropical Storm Watch to a Warning, and a Hurricane Watch is also in effect. High waves and dangerous rip currents are likely to affect Bermuda and much of the U.S. East Coast in the next couple of days.

The storm is moving steadily northwest at 18 mph from a position a little less than 600 miles south of Bermuda. A more northerly turn is expected by Saturday.

Image (click to enlarge): Hurricane Bill forecast track from National Hurricane Center

PM Update: Tropical Storm Ana Depressed, Bill Burgeons, Claudette Continues

11 pm EDT Update: As of 11 pm, Ana was moving across the Leeward Islands with 35 mph winds, Bill had strengthened to just below hurricane force at 70 mph, and Claudette (50 mph) was about to make landfall on the Florida Panhandle from a position about 25 miles west of Panama City.

Original post:
Tropical Storm Ana has continued weakening this afternoon and is now a tropical depression with maximum winds of 35 mph as of 5 pm. Little change in intensity is expected in the next 24 hours, but it could degenerate further into a tropical wave tonight. Tropical Storm Watches are in effect, however, from the Dominican Republic eastward through much of the northeastern Caribbean Islands.

Satellite images show that Tropical Storm Bill has developed an impressive-looking structure, including a central dense overcast, banding, and upper-level outflow. It now has maximum winds of 65 mph. The models continue to forecast strengthening, and one of them has a 38% chance of a 30 kt. increase in wind speed in the next 24 hours. Several of them show Bill becoming a Category 4 hurricane within 5 days.

Tropical Storm Claudette continues approaching a likely landfall on the Florida Panhandle tonight. Winds remain at 50 mph, but some strengthening is still possible. The main threat from this storm is heavy rain, with amounts of 3-6" and isolated maximums of 10" expected. At 4 pm CDT, the storm was centered about 40 miles west-southwest of Apalachicola, Florida moving northwest at 14 mph.

Images (click to enlarge): Forecast tracks for Tropical Storms Bill (upper) and Claudette (middle) and combined 5-day probability of tropical storm force winds from National Hurricane Center

Tropical ABC's: Tropical Storm Claudette Joins Weaker Ana and Stronger Bill

An area of heavy thunderstorm activity in the eastern Gulf of Mexico became Tropical Depression 4 overnight, and it was declared Tropical Storm Claudette at 11:15 CDT based on radar observations. Aircraft reconnaissance subsequently indicated maximum winds have reached 50 mph with higher gusts, and some strengthening is possible before landfall on the northern Gulf Coast of Florida tonight. A Tropical Storm Warning is in effect from the Alabama/Florida border eastward to the Suwanee River in Florida. The storm is centered about 40 miles south of Apalachicola, Florida and is moving northwest at 14 mph.

Meanwhile, Ana has been found to be weakening. Aircraft measurements indicate that the storm is poorly organized, is barely a tropical storm, and could dissipate later today. Maximum winds are 40 mph. As a precaution, a Tropical Storm Watch remains in effect for Puerto Rico, the U.S. and British Virgin Islands, and a number of other islands in the northeastern Caribbean.

Tropical Storm Bill, on the other hand, has strengthened this morning to maximum winds of 60 mph as it moves west-northwest at 16 mph from a position over 1500 miles east of the Lesser Antilles. Favorable environmental conditions in the form of light wind shear and warm water temperatures are expected to contribute to more strengthening, and Bill is forecast to become a hurricane within 24 hours, and a major hurricane in the next several days.

Images (click to enlarge): Forecast tracks for Tropical Storms Claudette (upper) and Bill (lower) from National Hurricane Center

Tropical Update: Bill is Born Advisories for Ana

Satellite imagery indicates that the Tropical Depression formerly known as Three has become better organized and is now Tropical Storm Bill with maximum winds of 40 mph. Bill is in the deep tropics, further south than Ana, and is well within the easterly trade winds. It's moving steadily a little south of due west around 16 mph, and a gradual turn to the west-northwest is expected. Bill has a large circulation and has favorable conditions for development, including light wind shear and warm water temperatures. It is expected to become a hurricane within 4 days.

Meanwhile, little sister Ana still has maximum winds of 40 mph as it continues moving westward at 17 mph. The Netherlands Antilles government has issued a tropical storm watch for St. Maarten, Saba, and St. Eustatius.

Images (click to enlarge): Tropical Storms Bill and Ana forecast tracks from National Hurricane Center

Tropical Season Heats Up: Ana Arrives Brother Bill Behind?

After being given up for dead, the remnants of Tropical Depression 2 organized enough this morning to become Tropical Storm Ana, the first of the 2009 Atlantic season. Meanwhile, a larger tropical wave to the southeast of Ana has become Tropical Depression 3; it is likely to develop into Tropical Storm Bill in the next day or so.

At 11 am AST/EDT, Ana's maximum winds were 40 mph, and some slow strengthening is predicted. Movement is toward the west at 16 mph, with a gradual turn to the west-northwest expected. This track could bring the storm near the Leeward Islands by Monday. Ana is a small storm, and it is moving through a hostile environment of westerly wind shear and dry air, but the forecast track takes it over increasingly warm water. Most of the intensity models indicate that it could develop into a hurricane. Given the conflicting influences, however, the intensity forecast is more uncertain than usual; the official forecast keeps it lower than the models, at tropical storm strength.

Tropical Depression 3 formed late this morning in the eastern Atlantic. Maximum winds are 35 mph and movement is westward at 17 mph from a position about 740 miles west-southwest of the Cape Verde Islands. The intensity forecast calls for the depression to become a tropical storm in the next 12 hours and a hurricane within 3 to 4 days. All of the intensity models are predicting hurricane strength, with one of them forecasting a major hurricane. If it develops as expected, the storm will be named Bill.

Images (click to enlarge): Tropical Storm Ana and Tropical Depression 3 forecast tracks from National Hurricane Center