Tropical Storm Isaac five-day forecast track. NHC/NOAA graphic
By Caribbean News Now contributor
MIAMI, USA -- Tropical Storm Isaac churned through the Caribbean toward the Dominican Republic and Haiti on Thursday. The storm dumped heavy rain across eastern and southern Puerto Rico and whipped up waves as high as 10 feet as it moved through the region.
While the storm’s track has shifted slightly to the west, “significant uncertainty remains,” the National Hurricane Center in Miami said on Thursday.
The center’s tracking maps and forecast analysis no longer show Isaac becoming a hurricane before reaching Hispaniola, which is shared by the Dominican Republic and Haiti.
At 5:00 pm EDT on Thursday, the centre of Tropical Storm Isaac was located about 180 miles south-southwest of San Juan, Puerto Rico, and about 255 miles southeast of Santo Domingo, Dominican Republic, moving toward the west-northwest near 16 mph.
This general motion is expected to continue through Saturday and, on the forecast track, the centre of Isaac will approach the south coast of the Dominican Republic on Thursday night, move near or over the south coast of the Dominican Republic and Haiti on Friday and approach southeastern Cuba on Friday night.
Maximum sustained winds are near 40 mph, with higher gusts and some strengthening is forecast during the next 48 hours.
A hurricane warning is in effect for:
• South Coast of Dominican Republic from Isla Saona westward to the Haiti-Dominican Republic southern border
A tropical storm warning is in effect for:
• British Virgin Islands
• Puerto Rico, Vieques, Culebra and the US Virgin Islands
• North coast of Dominican Republic from the Haiti-Dominican Republic northern border eastward to north of Isla Saona
• Southeastern Bahamas, including Acklins, Crooked Island, Long Cay, The Inaguas, Mayaguana and the Ragged Islands, and the Turks and Caicos Islands
A tropical storm watch is in effect for:
• The Cuban provinces of Camaguey, Las Tunas, Granma, Holguin, Santiago de Cuba and Guantanamo.
Interests in Jamaica, the remainder of Cuba, the remainder of The Bahamas, South Florida and the Florida Keys should monitor the progress of Isaac.
Tropical storm conditions are still possible over portions of Puerto Rico and the US and British Virgin Islands on Thursday evening. Hurricane conditions are still possible over portions of the Dominican Republic by Friday and over portions of Haiti on Friday or Friday night. Tropical storm conditions are expected over the southeastern Bahamas and the Turks and Caicos Islands by late Friday. Tropical storm conditions are possible over southeastern Cuba by Saturday.
Total rainfall accumulations of 8 to 12 inches, with maximum amounts of 20 inches, are possible over Hispaniola. These rains could cause life-threatening flash floods and mud slides. Total rain accumulations of 2 to 4 inches, with maximum amounts of 6 inches over higher terrain, are possible over Puerto Rico and the Virgin Islands. Total rain accumulations of 4 to 8 inches are possible over the northern Windward Islands and the Leeward Islands.
A storm surge will raise water levels by as much as 3 to 5 feet above normal tide levels in areas of onshore winds along the coast of Hispaniola. Storm surge in Puerto Rico, as well as the US and British Virgin Islands will gradually subside on Thursday night. Near the coast, the surge will be accompanied by dangerous waves.
Dangerous surf and rip current conditions will affect the Windward Islands, Leeward Islands, Virgin Islands and Puerto Rico during the next couple of days.
Tropical Storm Joyce five-day forecast track. NHC/NOAA graphic
Meanwhile, Tropical Storm Joyce formed in the open Atlantic on Thursday but satellite imagery indicated that Joyce had become less organized on Thursday afternoon.
At 5:00 pm EDT, the centre of Tropical Storm Joyce was located about 1,280 miles east of the Leeward Islands, moving toward the west-northwest near 14 mph. Some erratic motion was possible Thursday night but a general west-northwestward to northwestward motion with some increase in forward speed is expected during the couple of days.
Shower and thunderstorm activity remained minimal in association with another tropical wave located between the west coast of Africa and the Cape Verde islands. Any development of this disturbance is expected to be slow to occur and this system has a low chance -- 10 percent -- of becoming a tropical cyclone during the next 48 hours as it moves generally westward at about 15 mph.