A winter storm is expected to deliver moderate to heavy snow to different parts of Greene and Columbia counties Sunday night and Monday.
Depending on where you live will depend on how much snow will accumulate, local meteorologist Allan Porreca said Friday.
Valley areas along the Hudson River could see as little as 2 to 5 inches, while higher elevations of Greene and Columbia counties may receive between 12 and 18 inches, Porreca said.
Current computer models indicate that snow will begin late Sunday, about 11 p.m. Snow will continue for several hours before it mixes with sleet and freezing rain, and then plain rain as warm air works its way up the Hudson Valley.
Precipitation will remain as all snow in the higher elevations, Porreca said.
The storm will involve two low pressure systems. The stronger system is expected to stay over land. The second low will stay over water and push warmer air into the region, Porreca said.
An increasing wind, from the east northeast will cause downsloping in the Hudson Valley, which will limit the snow totals, Porreca said.
Downsloping is the process that occurs when a stream of air is forced to descend a mountain. As the air descends, it undergoes a series of changes that result in a warming and drying effect, according to the National Weather Service.
Winds during the snowfall are expected to be gusty. Parts of the Catskills and Berkshires may see wind gusts over 50 mph, Porreca said.
Temperatures when the storm begins should be around 25, but will rise into the upper 30s by Monday morning, Porreca said.
The National Weather Service has issued a Winter Storm Watch for several counties, including Western Greene County, from 10 p.m. Sunday until 10 p.m. Monday.
Frigid temperatures are forecast across the area all day Saturday.
The National Weather Service has issued a Wind Chill Warning for Western Greene County effective 7 p.m. Friday through noon Saturday. Wind chills as low as 25 to 35 below zero are expected.
The rest of Greene and Columbia Counties are under a Wind Chill Advisory, with wind chills as low as 15 to 25 below zero.
After the storm leaves the area, the forecast for Tuesday is partly sunny with a high temperature of 30 degrees.