Possibly more than 12 inches of snow forecast on Long Island

A major winter storm is forecast to leave between 6 and 15 inches (15 and 38 centimeters) of snow on Long Island this weekend, amid a cold snap that will cause sub-zero wind chills, according to experts.

The National Weather Service (NWS) issued a winter storm warning for Nassau and Suffolk counties from 3 a.m. Sunday to 6 p.m. Monday.

The agency also issued a cold weather advisory that will be in effect until 10 a.m. this Saturday.

There is a high chance of more than 6 inches (15 centimeters) of snow and a moderate chance of more than 1 foot of snow (30 centimeters), although the track, timing and intensity of the storm will be clear before it arrives.

“Snow could mix with or turn into sleet along the coast Sunday night, limiting accumulation to the lower part of the forecast range,” forecasters with the Upton-based National Weather Service said in the storm warning. “The largest accumulations are expected inside.”

The snow is expected to leave roads and bridges slippery, creating hazardous driving conditions, with wind-blown snow reducing visibility to 400 metres.

Forecasters urged drivers to avoid traveling unless absolutely necessary between Sunday and Monday, and to use extreme caution if they do.

“Consider bringing a winter storm emergency kit, including items such as tire chains, jump cables, flashlight, shovel, blankets and additional clothing,” the NWS said. “Also carry water, a first aid kit, and anything else that will help you survive if you become stranded.”

The storm comes at a time when experts recommend preparing for an extended period of frigid temperatures from Friday night through the middle of next week.

“Very low thermal sensations are expected, up to 10 degrees Fahrenheit (-12 °C”),” the National Meteorological Service indicated in the cold warning.

«Low temperatures with wind could cause hypothermia if precautions are not taken. “Frostbite and hypothermia will occur if unprotected skin is exposed to these temperatures.”

The public is urged to dress warmly, use space heaters correctly and not use generators or grills indoors, and to keep an eye out for elderly family members, friends and neighbors.