Forecast discussion: High pressure over the Great Lakes continues to give eastern Massachusetts dry, calm weather. However, this evening, the high will help set up bitterly cold temperatures. Overnight lows will fall into the single digits, and any wind will help create wind chills of 0 to 5 below zero. So, please dress warmly if you have to be out and about during the overnight.
This high will continue our streak of dry and sunny weather, as well as the below normal temperatures. However, the streak will end, as the high moves out into the Atlantic. This will allow a low pressure system in the Southern U.S. to move east-northeast. It will bring havoc to Georgia, Alabama, and into North and South Carolina. By Wednesday night, the low will begin a trek into the Atlantic, and become a Nor’easter. So, what can Massachusetts expect from this system?
I can tell you that most of Massachusetts will see snowfall. The National Weather Service has issued a Winter Storm Watch for most of eastern Massachusetts, but not for Boston, or for Essex County. It does run into Bristol County and around into towns like Lawrence from 7 a.m. Thursday until 7 p.m. Snow will begin to fall in the capital city just before the start of the morning commute. We could see bands of heavy snow, with visibilities lowering to half a mile. Now comes the tricky part. The low will allow warmer air to come into the area, so the precipitation will begin to change over. The Cape and Islands will be too warm for snow, so I am calling for just plain rain. Going into Plymouth County, I only see 1-3 inches in the area, as it will see more of a mix of sleet and rain by the afternoon. For the Boston area, 3-6 inches are possible, especially when we gain an inch back from evening snow showers. Finally, north and west of Boston will see the heaviest snowfall, with 6-12 inches. See the attached photo to see the complete snowfall map.
At this time, my confidence in the forecast is fair. Three of the four major computer models are agreeing on the general track of the low. However, the difference of the low’s center moving 30 miles east or west could greatly change this forecast. So, come back tomorrow night for any further updates.
We will see limited sunshine by Friday afternoon, with the chance of more snow showers for a small period of time Saturday morning. Right now, the American and United Kingdom models keep the low to our south as it passes into the Atlantic. A strong high pressure system will bring cold, dry weather on Sunday and for part of Monday. A new low developing off the coast of North Carolina will bring the risk of some snow Monday night, before a mix of rain and snow is possible next Tuesday.
72 hour forecast:
Tonight: Clear skies and bitterly cold with a low of 6.
Wednesday: Mostly sunny with increasing clouds by the evening commute. We will see a high of 24 with winds turning to the southeast at 6-9 mph by the late afternoon.
Wednesday night: Overcast skies with light snow starting around 5 a.m. We will see a low of 21 with southeasterly winds at 5-8 mph.
Thursday: Moderate snow by the morning commute. Snow could come down at 1-2 inches per hour, and lower visibilities. Winds will be increasing through the afternoon. By the early afternoon, Boston will see a mix of sleet and rain, while the Cape and Islands change over to rain. We will see a high of 36.
Thursday night: Windy with sleet or rain changes back to snow showers by midnight. Snow ends by 6 a.m. We will see a low of 31.
Friday: Partly sunny with a high of 38.
Friday night: Mostly cloudy with snow showers possible by 2 a.m. and a low of 28.
Saturday: Mostly cloudy with scattered snow showers ending by noon. Highs 34-37, lows 13-16.
Sunday: Mostly sunny. Highs 24-27, lows 9-12.
Monday: Partly to mostly sunny with possible light snow in the evening. Highs 29-32, lows 21-24.
Tuesday: Light snow/rain possible in the morning, ending in the afternoon. Highs 39-42, lows 20-23.