Friday 12/4/20 AM Update

Good morning!

We have a storm on our hands, so let’s quickly run down the next day and a half or so first. With mostly cloudy skies, expect a high around 53 today, with a southwest wind of 5-10 mph. Tonight will be mostly cloudy, with a low around 39, a light southwest wind, and a chance of rain late. Expect heavy rain tomorrow morning, with the high temperature of 43 occurring around mid-morning.

weather 2020-12-04.001

Temperatures then fall to around the freezing mark by midday as heavy rain flips over to heavy snow. For a time during the afternoon and evening, snow rates well over 1″ per hour are possible. This will make for poor driving conditions, and whiteout conditions are possible at times with a northwest wind of 5-15 mph gusting up to 35 mph. Snow wraps up by around midnight or so Saturday night. Power outages will also be possible due to the weight of the snow. My going forecast calls for 5-10″ of snow for much of northeast Massachusetts and southeast New HampshireMore details regarding uncertainty follow.


There is increasing confidence in significant snowfall amounts as guidance is settling in on a classic “benchmark” track that is favorable for snowfall in interior eastern New England. However there is still some uncertainty here. Given the likelihood of an especially heavy snow band setting up, it’s possible we could over-perform even the 5-10″ forecast; when all is done, some places may see over a foot of snow, but confidence is not high enough to add a 10″+ tier. Depending on trends, such an update may be necessary this evening (such an update won’t happen until after 9 pm, because of work).

The other end of the uncertainty stick is with amounts at both the immediate coastline as well as in western New England. The obvious caveats always apply at the coast regarding warmer temperatures, but temperatures will be marginal everywhere and this storm is reliant on very heavy snow rates, so it’s possible that heavy snow could occur right up to the coast – likely not to the same degree as inland, but the northeast MA coast will likely approach the 6-inch snow mark.

As for western New England, the system’s eastward trend is leaving less overall precipitation for that region, and some guidance is now indicating a near-shutout out that way. There is still some guidance on board with heavy snow out that way, so while the odds are decreasing, there is still tons of uncertainty in western New England that should resolve soon.

While this now seems very unlikely, it’s also not entirely impossible that this ends up being an underperforming system locally as well. Overall, this forecast is much less stable than we typically have so close to the onset of a storm. 

The system’s departure gives way to temperatures falling to around 26 Saturday night, with a northwest wind of 10-20 mph, gusting up to 35 mph, and mostly cloudy skies. Skies turn mostly sunny Sunday, with a high around 35. Sunday night will be mostly clear and 21. Monday will be mostly sunny and 35; Monday night will be mostly clear and 17; Tuesday will be 35 and mostly sunny.

weather 2020-12-04.002

Have a great day!

Published by Nathan Coram

Hello! I'm Nathan Coram, a 20 year old meteorology student and weather geek, and am in my junior year at UMass Lowell as a meteorology major. I am the current Vice President of the UML American Meteorological Society Local Student Chapter. Prior to at UML, I attended the Dracut school system for my K-12 years, having graduated from Dracut High in 2018. I first got into weather with the December 2008 ice storm, which knocked out my electricity for 4 days. I had no idea how it could be raining and becoming ice immediately, and how rain can knock out power. (Now I do - warm layer aloft, cold air at surface). But I didn't really get into it until the heat of July 2010 and specifically a few severe weather events during that month, followed by the year 2011, which featured several high profile weather events. Since then I have had a growing interest, and am hoping to make it into the meteorology field, preferably with NOAA/NWS. But for now, I'm blogging here on Dracut Weather (also on Twitter and Facebook), helping with the UML Weather Center social media, and tweeting about the weather on my own account as well. Thanks for visiting!

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