Tag Archives: Ft. Lauderdale

Isaias Crosses Andros Island, Weakens to Tropical Storm

The center of former Hurricane Isaias crossed Andros Island on Saturday afternoon and it weakened to a tropical storm.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Isaias was located at latitude 25.1°N and longitude 78.7°W which put it about 115 miles (185 km) southeast of Ft. Lauderdale, Florida.  Isaias was moving toward the northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 993 mb.

A Hurricane Warning was in effect for the portion of the coast from Boca Raton, Florida to the Flagler/Volusia County Line.  A Hurricane Waning was also in effect for the Northwestern Bahamas including Andros Island, New Providence, Eleuthera, the Abacos, the Berry Islands, Grand Bahama Island, and Bimini.

Tropical Storm Warnings were in effect for the portions of the coast from Ocean Reef to Boca Raton, Florida and from the Flagler/Volusia County Line to Ponte Vedra Beach, Florida.  A Tropical Storm Warning was also in effect for Lake Okeechobee.  A Tropical Storm Watch was in effect for the portion of the coast from Ponte Vedra Beach, Florida to South Santee River, South Carolina.

The center of former Hurricane Isaias crossed over Andros Island on Saturday afternoon.  Normally, Andros Island does not have much of an impact on hurricanes, but combined with a less favorable environment it contributed to a temporary weakening of Isaias.   Tropical Storm Isaias consisted primarily of bands of showers and lower clouds after crossing Andros Island.  However, new thunderstorms began to develop northeast of the center of circulation during the past several hours and part of the eyewall appeared to be reforming.  Bands in the western and southern parts of Isaias still consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation.

Tropical Storm Isaias will move through an environment somewhat favorable for intensification during the next 36 hours.  Isaias will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough over the central U.S. will produce westerly winds which blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear, but they are likely to only affect the very top of the tropical storm.  Tropical Storm Isaias will move into a region where there is drier air in the middle and upper troposphere.  The circulation around Tropical Storm Isaias will reorganize and it is likely to strengthen back into a hurricane.

Tropical Storm Isaias will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Isaias toward the northwest during the next 24 hours.  Isaias will move more toward the north later on Sunday.  The upper level trough will turn Isaias toward the northeast on Monday.  On its anticipated track Tropical Storm Isaias is will approach the southeast coast of Florida near Ft. Lauderdale and West Palm Beach on Sunday.  Isaias is likely to be a hurricane when it approaches the coast.