The National Weather Service in Upton has issued a winter weather advisory for Nassau and Suffolk counties in advance of another snow storm that could dump 3-6 inches of white stuff on the region Tuesday night into Wednesday. The advisory will be in effect from 6 p.m. until noon Wednesday.The weather service said periods of snow could cause travel difficulties.“Be prepared for slippery roads and limited visibility,” the agency said on its website. “And use caution while driving.”The weather service is also warning of potential flooding along the south shore of Nassau and western Suffolk, with tides three feet above normal. Coastal areas could see “widespread flooding of vulnerable shore roads and/or properties due to height of storm tide,” the agency said.Snow is not expected to start falling until late Tuesday evening and could continue until 10 a.m. Wednesday, possibly disrupting yet another morning commute. Tuesday’s forecast calls for a high near 35 with the wind chill making it feel a few degrees cooler.Wednesday’s high is 39 degrees.The mercury will begin dipping Thursday, especially in the evening, with a low of 18 expected when the sun goes down. There is also a chance of snow Thursday and Friday.The weekend will be brisk. The weather service is predicting a high of 25 degrees on Saturday before the thermometer plunges into single digits in the evening. Valentine’s Day won’t be much better, with temperatures in the teens throughout the day Sunday. Sign up for our COVID-19 newsletter to stay up-to-date on the latest coronavirus news throughout New York Valentine’s Day is coming just in time to warm our collective hearts.One day after a light snow sprinkled Long Island, forecasters are warning of more snow and plunging temperatures for the remainder of the week.