Forecast discussion: Clear skies and windy conditions helped bring the low temperature down to 5 degrees at Logan Airport last night in Boston. Wind chill temperatures reached a low of 16 below zero. The Polar Express will continue this evening, as clear skies and light winds will help lower our temperatures back into the single digits. But, increasing clouds before dawn will stop temperatures from dropping.
As we move into Saturday, the winds will begin to change direction to the southwest, which is a warmer wind direction. Our high temperatures will actually be near freezing. But, moisture from a weak low in the Great Lakes will bring us some light snow by Saturday afternoon.
So, how do southwest winds help us? Well, a second low over the Texas Panhandle will move towards the Northeast U.S. This low will help bring in moisture from the Gulf of Mexico, but it will also bring in some much needed warmer air, thanks in part to those southwest winds. The warmer air in the lower levels of the atmosphere will also change our precipitation Saturday night will change from light to moderate snow to sleet and freezing rain. So, this will create problems on the roadway, but we will not be adding more significant snow totals to our already high snow pack.
Expect about 1-3 inches of snow before the changeover, with higher amounts the further north you travel. As we move into Sunday morning, temperatures will go above freezing, and the precipitation slowly changes to rain. But, this will be a moderate to heavy rain, and thus will condense the snow pack, making it heavier. So, for anyone with flat roofs, you may want to shovel and rake as much snow off as possible before Sunday. Rain will taper off during the early afternoon, and temperatures will fall, as the cold front pushes through the region.
So, by Sunday night, any rainfall and wet surfaces will freeze one again, as temperatures fall into the lower teens Sunday night. So, please take extreme caution if you have to drive during the morning commute on Monday. You may experience black ice and pockets of ice. High pressure will bring us sunny skies once again for Monday, but we will experience bitterly cold temperatures once again Monday night. Clear skies and light winds will help lower overnight temperatures near zero. The high will continue to give us dry weather into Tuesday, before we may see another potential snowstorm for Wednesday.
At this time, three of the four weather models were predicting a strong low pressure system along the coastline to give the Northeast U.S. significant snowfall. However, the American and now the European models do not believe this will happen. Instead, an Alberta Clipper type system from the Great Lakes will bring us light snow showers throughout the day. The United Kingdom and Canadian models believe the Great Lakes will be stronger, and we will see heavier precipitation, thanks to the merger of the second low off the coastline. Right now, my confidence in the forecast for Wednesday remains poor, now that there is further disagreement between the models.
We end the forecast period with dry weather, as a strong high pressure system will protect New England right into next Saturday. Despite us coming to the end of February, high temperatures will only reach the lower to middle 20’s.
72 hour forecast:
Tonight: Partly cloudy until 4 a.m. with increasing clouds. We will see a low of -1.
Saturday: Mostly cloudy skies with light snow developing by 4 p.m. We will see a high of 30 by the late afternoon. Winds will come from the south-southwest at 10-13 mph.
Saturday night: Light to moderate snow mixing with freezing rain, moving south to north. The capital city will see a mix by 3 a.m. We will see a low of 33 with temperatures rising. Winds will come from the south-southwest at 9-12 mph.
Sunday: Freezing rain changing to all rain by 9 a.m. We will see a high of 40. Patchy fog is possible by mid-morning. Rain may be heavy during the morning, tapering off by the early afternoon.
Sunday night: Clear skies and much colder with a low of 13.
Monday: Mostly sunny with a high of 19.
Monday night: Partly cloudy and bitterly cold once again with a low of 0.
Tuesday: Mostly sunny during the morning, with increasing clouds during the afternoon. Highs 20-23, lows 13-16.
Wednesday: Overcast with light to moderate snow possible. Highs 30-33, lows 14-17.
Thursday: Mostly sunny. Highs 23-26, lows 7-10.
Friday: Mostly sunny. Highs 20-23, lows 9-12.