Category II Hurricane Dennis, with sustained winds of 105mph, will pass between Haiti and Jamaica this afternoon on a northwest course at 15mph. Dennis has moved steadily to the northwest over the past 8 hours, so this is a change in movement rather than a 'jog' in its track. This course change is good evidence that Dennis has reached the western extent of the Atlantic subtropical ridge and he is now moving around the edge of that ridge. The Atlantic ridge is already showing signs of withdrawal to the east as a weakness in the ridge begins to form between the remnants of TD Cindy to the north and Dennis to the south - showers have already made an unexpected appearance along the Florida east central coast. The Atlantic ridge will probably split off a smaller high pressure area on or to the west of the Yucatan peninsula. Dennis will continue his northwesterly course, eventually turning more north northwesterly as he passes through this weakness aloft. Additional intensification is likely, however, the higher terrain of eastern Cuba will temper this strengthening on Friday. The GFS model has already shifted to the east and now predicts landfall at Apalachicola on Sunday. I expect that by 5pm the National Hurricane Center will adjust their forecast track more to the east as well. It would not surprise me to see the GFS model make an additional adjustment of the track to the east later tonight. If Dennis is to reach Category III status, it will need to do so before it encounters Cuba - additional intensification is still likely.

FROM NHC: ...HURRICANE WATCH FOR THE FLORIDA KEYS...TROPICAL STORM WATCH FOR
THE SOUTHERN FLORIDA PENINSULA...

AT 11 AM EDT...1500Z...THE GOVERNMENT OF CUBA HAS EXTENDED THE
HURRICANE WATCHES AND WARNINGS WESTWARD. A HURRICANE WARNING IS NOW
IN EFFECT FOR THE PROVINCES OF MATANZAS...VILLA CLARA...
CIENFUEGOS...SANCTI SPIRITUS...CIEGO DE AVILA...CAMAGUEY...LAS
TUNAS...GRANMA...SANTIAGO DE CUBA...AND GUANTANAMO. A HURRICANE
WATCH IS NOW IN EFFECT FOR THE REMAINING PROVINCES OF CUBA
INCLUDING THE ISLE OF YOUTH...PINAR DEL RIO...LA HABANA...CIUDAD DE
LA HABANA...AND HOLGUIN.

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
WITHIN THE WARNING AREA WITHIN THE NEXT 24 HOURS. PREPARATIONS TO
PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION.

AT 11 AM EDT...A HURRICANE WATCH IS ISSUED FOR ALL OF THE FLORIDA
KEYS AND FLORIDA BAY. ALSO AT 11 AM EDT...A TROPICAL STORM WATCH
IS ISSUED FOR ALL OF THE SOUTHERN FLORIDA PENINSULA FROM GOLDEN
BEACH SOUTHWARD ON THE EAST COAST AND SOUTH OF BONITA BEACH ON THE
WEST COAST.

A HURRICANE OR TROPICAL STORM WATCH MEANS THAT HURRICANE OR TROPICAL
STORM CONDITIONS...RESPECTIVELY...ARE POSSIBLE WITHIN THE WATCH
AREA...GENERALLY WITHIN 36 HOURS.

A HURRICANE WARNING IS IN EFFECT FOR THE SOUTHWESTERN PENINSULA
OF HAITI FROM THE DOMINICAN REPUBLIC BORDER WESTWARD...ALL OF
JAMAICA...AND ALL OF THE CAYMAN ISLANDS.

FORECAST: I expect Hurricane Dennis to complete his crossing of Cuba at 23N 80W late Friday evening and emerge in the Florida Straits as a minimal hurricane. Dennis should then move through the Keys (Marathon to Key West?) as a Category II hurricane early Saturday morning. Dennis would then move just offshore the west coast of the peninsula as it moves north northwest to a final landfall between St Mark's and Cedar Key by Sunday afternoon. The journey along the west coast would likely be as a strong Category II (perhaps even a minimal Category III) hurricane. This would bring hurricane force winds over the western half of the peninsula and tropical storm force winds elsewhere in the state for most of the weekend - except earlier in the Keys and south Florida. Heavy rain and considerable flooding over just about the entire state of Florida this weekend. The time to prepare for this possibility - is now! Monitor the movement of Dennis this evening and Friday and be ready to take necessary precautions should the forecast track AND THE AREA OF DANGEROUS WIND, STORM SURGE AND FLOODING RAIN adjust closer to your area. More later.
ED