Forecast discussion: Boston has been receiving some pretty nice weather the last few days. This is due to a high pressure system that settled over Northern New England on Thursday. The high will stick around for most of the daytime hours, before it begins moving into the Atlantic. Also, this weekend is going to be milder, as temperatures will be about 15 to 20 degrees warmer.
However, it is not the high pressure system that is causing this warm weather. Actually, it is a low we should be giving thanks to this weekend. An upper level low, to be exact, in the atmosphere will create southwest flow. This flow will allow air coming off the tropical jet to begin filtering back north into New England. However, this will only last for a few days.
The high will also keep a very strong area of low pressure moving onto the east coast from Florida away from the region. There is a chance the Cape and Islands receives isolated showers Friday night into Saturday morning. But, the high will remain strong enough to move the low into the Atlantic. The high will protect us until Saturday night. A weak cold front out of the Great Lakes will bring the slight chance for some snow showers late Saturday night into the middle of Sunday morning. No snowfall is expected. We should return to mostly sunny skies by the afternoon, as the front dissipates. However, the front will become a weak disturbance, keeping cloudy skies over us for Sunday evening.
As we head into Monday, a stronger disturbance will form to the south of Southern New England. This disturbance will create some isolated snow and/or rain showers Monday morning, and ending by the evening. At this time, not all the computer models agree on whether there is enough moisture in the atmosphere to even create precipitation. So, I may be tweaking Monday’s forecast over the next few days.
However, all the computer models are agreeing on a big Nor’Easter forming for the middle of next week. This low will bring the chance for some snow, sleet, and rain. The problem right now is the low’s track. If the low’s center moves to the west of us, we will be in the warmer sector, meaning more rain than snow. But, if the low moves out to sea, or the center moves to our south and east, we will be in the colder area, meaning more wintry precipitation. At this time, it appears we will be in the warmer sector, meaning more rain than snow. However, my confidence in the forecast after Tuesday is very low. Based on where the computer models place the low, a difference of even 40 miles means the difference between all snow and all rain.
72 hour forecast:
Tonight: Clear skies but not as cold with a low of 15.
Friday: Mostly sunny and milder with a high of 38. Winds will come from the east-southeast at 6-9 mph.
Friday night: Mostly cloudy with a possible isolated showers along the Cape and Islands. We will see a low of 29 with north-northeast winds of 10-13 mph.
Saturday: Partly sunny with a high of 45.
Saturday night: Mostly cloudy with isolated snow showers starting around 10 p.m. and a low of 29.
Sunday: Mostly cloudy with possible snow showers ending by mid-morning. Mostly sunny skies expected by the early afternoon. We will have a high of 38.
Sunday night: Mostly cloudy with a low of 26.
Monday: Mostly cloudy with isolated snow/rain showers by the morning, ending by the evening. Highs 40-43, lows 30-33.
Tuesday: Mostly sunny, with increasing clouds through the evening. Highs 42-45, lows 24-27.
Wednesday: Cloudy with snow showers in the early morning, turning moderate by the afternoon. Highs 34-37, lows 23-26.
Thursday: Snow dissipates through the early morning, and becoming mostly sunny. Highs 30-33, lows 15-18.