Forecast discussion: After several days of talking about it, we are less than 24 hours away from our first significant winter storm of the season. As high pressure gave Providence bright sunshine on Friday, Saturday will be a totally different matter.
With the impending storm, the National Weather Service has put out three warnings for the state. Most of Massachusetts is under a Winter Storm Warning, starting at 1 p.m. Saturday, and continuing into 1 p.m. Sunday. Parts of Bristol and Plymouth Counties are under a Winter Weather Advisory, for the same time limit. The difference between the two warnings is the Winter Weather Advisory is for areas expecting less snow, due to a faster changeover from snow to a wintry mix early Sunday morning. Finally, the Cape and Nantucket are under a Coastal Flood Advisory from 8 a.m. to noon on Sunday. This is due to higher waves of 5 to 10 feet outside the Harbor, along with high tide, which will make seas near the shoreline 1-2 feet higher than normal.
Right now, the low’s center is moving into eastern Texas, with snow already falling from Arkansas to Indiana. A frontal boundary is already over Massachusetts. By around noontime, we should begin to see a few flurries fall. By about 4 p.m., we will begin to see some light snow fall in the capital city. The snow will become heavier as we get into the early evening hours, about 9 p.m. The heaviest snow bands should arrive by about 11 p.m., and it could be falling at an inch or two per hour.
As we head into early Sunday morning, the low’s center will be off of Cape Cod. This will allow for some warmer air to move in. This will help change the snow to a mix of freezing rain and rain. I am expecting the mixing to occur at about 3 a.m. This will continue into mid-morning. By about 10 a.m., it will change to all rain. All precipitation will end by around 3 p.m., but could end as snow showers.
So, what are the final snowfall totals? For Boston itself, I am calling for 4-7 inches. Everyone to the east of of Boston will only see 2-4 inches, as they changed over to a mixture quicker than anyone else in the state.
Monday will be dry and sunny, but overnight lows will fall into the lower teens, thanks mostly in part to the fresh snow pack. Despite mostly sunny skies, the sun’s rays will not be absorbed by the ground, but rather bounce back into space. By Tuesday, an Alberta Clipper system will bring us the chance for some scattered snow showers by the afternoon, and continue into Wednesday morning.
We will return to drier weather by the mid-afternoon on Wednesday, with mostly sunny skies for Thursday. With winds shifting from the south, our temperatures will rebound as well, with temperatures climbing into the lower 40’s by Friday. Another storm system may arrive by Friday evening, but this time, we will see more rain showers from the system. But, the precipitation may end as some wet snow, as the cold front passes through Saturday evening.
72 hour forecast:
Tonight: Clear skies early, with increasing clouds towards dawn. We will see a low of 14.
Saturday: Overcast by mid-morning, with light snow starting around 2 p.m. We will have a high of 24. Snow will become heavier throughout the afternoon and early evening. Winds will come from the east-northeast at 9-12 mph.
Saturday night: Moderate to heavy snow between 10 p.m. to 3 a.m. Snow will mix with sleet from 3 a.m. to 6 a.m. Temperatures will remain around 25. Winds will be increasing from the northeast to 20-25 mph by 3 a.m.
Sunday: Precipitation will change to a mix of freezing rain and rain by dawn, before becoming rain showers and drizzle by mid-morning. All precipitation ends by the early afternoon. We will see a high of 35 with strong winds.
Sunday night: Partly cloudy with diminished winds and a low of 16.
Monday: Mostly sunny with a high of 24.
Monday night: Mostly cloudy after midnight and a low of 9.
Tuesday: Overcast with possible snow showers by the afternoon. Highs 30-33, lows 23-26.
Wednesday: Scattered snow showers through the morning, but becoming partly sunny by the afternoon. Highs 34-37, lows 21-24.
Thursday: Mostly sunny. Highs 32-35, lows 19-22.
Friday: Overcast by the early afternoon with rain showers by the evening. Highs 40-43, lows 31-34.