Residents are urged to expedite preparations in advance of the storm approaching the territory. Photo: DDM

Current Location: 15.6N 56.7W

Geographic Reference: 300 miles east of Dominica

Movement: West at 17 mph

Max Winds: 40 mph gusting to 50 mph

Organizational Trend: Slowly Increasing

Forecast Confidence: Average

Current Hurricane Severity Index: 2 (1 size / 1 intensity)

Peak Forecast Hurricane Severity Index: 9 (3 size / 6 intensity)

Forecast

Isaac continues to move slightly north of due west. Model guidance indicates that this track should continue. Therefore, the short term track has been shifted slightly to the north of the previous forecast. This is expected to bring the system through the Leeward Islands this afternoon or evening and south of Puerto Rico and the Virgin Islands tomorrow. The latest indications are that there will be enough of a weakness in the ridge of high pressure to the north of Isaac to allow for a more west-northwest track after 48 hours. This is likely to bring the system inland over the Dominican Republic and Haiti on Friday. After tracking over Cuba on Saturday and Sunday, a more northwesterly track is expected. In 5 days, Isaac may be in a position to directly impact South Florida.

The latest aircraft data indicates that the pressure has fallen slightly. This indicates that Isaac is slightly better organized. However, the system is still experiencing northeasterly shear. Therefore, only steady intensification is forecast. Isaac is forecast to become a hurricane in 48 hours and strike the Dominican Republic with 85 mph winds. Due to the very high mountains on Hispaniola, it is expected to weaken to a tropical storm. Little change is forecast while interacting with Cuba. Once it emerges into the Florida Straits, environmental conditions are expected to be quite favorable for intensification. Therefore, Isaac is forecast to regain hurricane status as it approaches South Florida. It should be noted that the intensity would likely be somewhat higher than indicated here if the system does not make landfall in the Dominican Republic.

Expected Impacts on Land

Lesser Antilles including St. Lucia: Heavy squalls are moving through the area now. These squalls will likely last through Thursday afternoon. Wind gusts to 65 mph and heavy rain are likely for the Leeward Islands, from Guadeloupe through Anguilla. In Dominica, Martinique and St. Lucia, winds are likely to remain well below tropical storm intensity. However, some squalls may occur Wednesday through Thursday afternoon with gusts to 50 mph. The southernmost squalls may extend as far south as Trinidad.

Virgin Islands and Puerto Rico: Occasional heavy squalls are expected to begin late Wednesday evening and continue through late Thursday or early Friday. Wind gusts of 60 mph to 70 mph possible in the heavier squalls.

Dominican Republic: Hurricane conditions are likely for the southern coast Friday morning and afternoon. Heavy rainfall, flooding, and mudslides are likely throughout the island of Hispaniola.

Expected Impacts Offshore

Eastern Caribbean: Tropical storm force winds are likely for the eastern Caribbean Sea Wednesday evening through Thursday. Wind gusts up to 70 mph will be possible in the heavier squalls.

Residents are urged to expedite preparations in  advance of the storm approaching the territory. The Department of Disaster Management will continue to monitor and storm and provide updates when necessary. Please visit the DDM’s website at www.bviddm.com and subscribe for updates.