Already responsible for triggering significant flooding across Puerto Rico, Isaac threatens to cause similar problems across Hispaniola, Cuba and Jamaica into this weekend.
After moving through the Leeward Islands earlier this week and south of Puerto Rico on Thursday, Isaac was moving south of Hispaniola Friday with showers and squalls spreading into the island and across Puerto Rico.
The worst effects in terms of rain in these areas will occur through Saturday morning as tropical moisture is pumped in on the eastern flank of the storm.
Puerto Rico was being inundated by torrential rain and an outer spiral band from Isaac Friday. Some roads have been blocked by mudslides or flooded. At least one bridge was washed out along the southern part of the island.
San Juan, P.R. radar from 1:15 p.m. EDT, Friday, Aug. 24, 2012.
"Training-effect rain and thunderstorms were blasting Puerto Rico like a giant fire hose during Friday," Expert Senior Meteorologist Alex Sosnowski said.
Isaac will be in a favorable environment for strengthening with warm water and weak wind shear.
Isaac may strengthen into a Category 1 hurricane before it reaches Cuba on Saturday. However, as Isaac interacts with the higher terrain of Cuba on Saturday, it should weaken once again.
"We are likely to see more bands of intense, persistent rainfall set up on Hispaniola, Cuba and even for a time yet in Puerto Rico into the weekend," Sosnowski added.
AccuWeather Senior Meteorologist Dan Pydynowski expects 4-8 inches of rain to fall across Puerto Rico, Hispaniola and Cuba with the potential for 10 inches or more in the mountains.
Coastal flooding occurred near Duffs Bottom on the western end of Tortula, British Virgin Islands Thurs., Aug. 23, 2012. Image taken by Radi Hassan.
A westward shift in Isaac's track on Friday will likely spell more trouble for Jamaica than previously thought.
A total of 1 to 2 inches of rain will overspread the island into Saturday. Locally higher totals are a concern and could lead to flash flooding and mudslides, especially across eastern areas.
Additionally, tropical storm-force winds will lash the southern half of the Dominican Republic, Haiti and eastern Cuba through Saturday. Hurricane-force winds are also a threat along southwestern Haiti and eastern Cuba.
AccuWeather.com Meteorologist Steve Travis contributed to this article.
The wet weather pattern will continue across the Seattle area through the first part of the weekend before drier weather moves in for the new week.
While blustery winds will howl on Christmas Day, Harrisburg will continue to escape more typical winter cold until next week.
While blustery winds will usher in colder air on Christmas Day, milder air will then quickly return to Pittsburgh on Friday.
After a blustery and cold weather pattern earlier in the week, temperatures will rebound across the Detroit area and winds will die down for the weekend.
After a blustery, cold weather pattern earlier in the week, temperatures will rebound and winds will die down for the weekend.
While blustery winds will howl on Christmas Day, Boston will continue to escape more typical winter cold until next week.
Texarkana, TX (2000)
Ice storm shut down the area. Complete power failure in the city.
The Northeast (2002)
First snowstorm to affect the region on Christmas day, since 1978. 30 inches fell in Cooperdtown NY, 21" fell in Tobyhanna, PA and 19.5 inches fell in Albany NY.
Trenton, NJ (1776)
Washington crossed ice clogged Delaware, marched on Trenton in driving sleet/snow- storm. 24" had fallen in Virginia, but heavy snow belt veered seaward. British surprised, captured - all recrossed river.