Friday 11 a.m.
The storm that unleashed a blizzard in the central Plains has weakened as expected. The low pressure area will be moving over the upper Great Lakes tonight and tomorrow morning then will drift toward the St. Lawrence Valley. Dry air has punched eastward from Illinois through Ohio, and that will help limit how much precipitation there can be between Washington, D.C., and New York City later today and tonight. However, with temperatures not far from the freezing mark, it pays to be alert for slippery conditions tonight, especially in the northern and western suburbs of those cities.
Tomorrow and tomorrow night, a low pressure area will take shape off the Middle Atlantic coast. Rain is likely in the I95 corridor from this storm tomorrow. The remains of the northern storm may cause some snow from central and eastern New York state into parts of New England tomorrow, with light accumulations possible. As the coastal storm strengthens into a full-blown nor'easter on Sunday morning, a band of heavy snow seems likely from eastern Connecticut and Rhode Island through Massachusetts, New Hampshire and southern Maine. In the southeasternmost portion of that area, temperatures will be borderline between rain and snow... and the outcome will greatly affect how much snow can accumulate. Places that get all snow can get more than 8 inches.
Early next week, another storm will move northeast from the southern Plains. While a lot of mild air will be pulled northward ahead of the storm, strong cooling will be taking place aloft from west to east. This could mean accumulating snow all the way from Iowa and Illinois to the mountains of Pennsylvania. The storm may get blocked as it heads toward eastern Canada. If that happens, there can be a multi-day siege of wind and chilly for the Great Lakes and much of the Northeast, with snow showers downwind from the Great Lakes into the mountains. This kind of setup will cause many people to long for spring, but I know Sam the Dog will appreciate any snow that gives him the opportunity to go "snow-bathing."
The cold front is embedded in a large area of clouds, showers and thunderstorms covering the middle of the country. It will advance past the Northeast coast by the end of the day Sunday. The frontal zone is shown on this picture from late morning Friday.
When weather systems are relatively weak, small scale variations cause forecast uncertainty because several different weather types (such as showers, sunshine, cloudiness, etc.) can coexist in the same region and change constantly. This map shows such a pattern:
Some of the thunderstorms can become severe, with damaging wind and brief cloudbursts of rain. The greatest chance for locally severe storms should be in the "S" areas highlighted on this map (based on the NWS Storm Prediction Center's guidance).
There is a slight risk for severe thunderstorms later today from north-central Tennessee up across Indiana and Ohio to Michigan and eastern Wisconsin (shown by the "S" area on the map below. Thunderstorms are not predicted for areas near the coast from Delaware to New England.
It is not going to snow any time soon, but in any type of weather the flag is a symbol of freedom. This holiday weekend we celebrate the contributions of those who were there to defend the freedoms we enjoy in these times.
Once again, the rain will miss much of central and northern New England. The region has been in a dry spell, as evidenced by its appearance on this U.S Drought Monitor map.