UPDATE: When Heavy Snow Will Hit The Hudson Valley

UPDATE — As predictions are firming up about the big winter storm about to deliver snow and high winds up the East Coast, the National Weather Service issued a winter storm watch Thursday afternoon for Putnam and Rockland Counties, joining the one already in place for Westchester.

• For Westchester, the NWS says heavy snow is possible with accumulations of 6 to 9 inches possible. Winds could gust as high as 50 mph from Friday evening through Saturday evening.
• For Putnam and Rockland, the NWS says total snow accumulations of 5 to 7 inches are possible. Winds could gust as high as 45 mph.

Travel could be very difficult. Gusty winds could bring down tree branches.

Still, forecasters are clear that these predictions are preliminary.

"This storm system will develop at the last minute as a deep trough digs into the eastern US Friday into Saturday," Alex Marra and Bill Potter of Hudson Valley Weather said Thursday afternoon. "For this reason, this forecast presents some extra challenges, and will increase the forecast uncertainty over the next 48 hours."

As of Thursday, chances were lower that the storm would track far enough to the west to raise accumulations in the mid-Atlantic, said Alex Sosnowski, AccuWeather senior meteorologist.

Hudson Valley Weather said what snow we get could start falling Friday afternoon, might intensify overnight, and would end Saturday afternoon or evening. Their preliminary forecast calls for 2-6 inches accumulating in the southeastern edge of the Hudson Valley, with a coating to 3 inches of snow for the rest.

A gale warning is in effect for Long Island Sound from 1 a.m. Saturday to 1 a.m. Sunday.

Long Island and New England look to feel more direct effects.

"The storm will strengthen into a bomb cyclone and a full-blown blizzard will ensue in eastern New England," Sosnowski said.

While the National Weather Service also says forecasts could change dramatically, it offered an early hour-by-hour look at southern Westchester: