[Updated at Noon, Saturday, December 10]
Low pressure will be moving into the area on Monday morning, bringing with it wintry precipitation. However, many challenges exist with this forecast, with a few notables: the inland extent of warm air, and the timing of any potential changeover.
With regard to the inland extent of warm air, most major guidance is bringing warm air (but by warm I mean upper 30s) for most of Eastern Massachusetts, but guidance also tends to overcook warm air in these situations. In any case, things look to warm later in the day bringing at least some sort of changeover for most, but it is possible nonetheless that warming comes a bit earlier and throws off the forecast. Right now, I am leaning toward cooler temperatures with a later changeover for most spots in my main forecasting area. In any situation, mixing is expected for a large amount of the storm at the coast, and I am playing it a bit safe and drawing the mainly snow area to be mainly outside of 495, with most spots inside I-95 and points south having an earlier changeover. Down across the south coast, the main precipitation type will be rain with snow or a wintry mix at the onset, with snow at the start followed by a wintry mix and then rain in the Gloucester-Boston-Providence-Hartford corridor, and snow to a wintry mix to rain just north of the prior line – along a Portland-York-Portsmouth-Newburyport-Framingham corridor through areas east of Worcester and north of Hartford, and then mostly snow with a changeover late for most of New Hampshire and Vermont, western/north-central and interior northeast Massachusetts, and parts of northern Connecticut.
The main non-snow precip type will be rain, with sleet and freezing rain also within the possibilities. If freezing rain does occur, ice accretion could be of a couple hundredths of an inch. If this risk increases, I will discuss it at more length in my next update.Yes, that’s a mouthful. Here’s a map:
That is subject to change, of course.
With the aforementioned solution, most of the area will see 4 to 7 inches of snow. The higher numbers in that zone will be in the higher terrain and further inland, and the lower numbers will be in the lower terrain and closer to the mix zones. Pay attention to the ranges. This forecast could change significantly in the next 36 hours, so stay tuned for later updates.
The snowfall will begin overnight Sunday night and precipitation wraps up early to mid afternoon Monday.
Ready for a whammy? The worst of the weather will come right during the Monday morning commute. Ouch. Depending on where you are, this could end up being either a period of heavy snow or a yucky wintry mix. In any case, this could warrant a commute where it will take much longer than normal to reach your destination where extreme caution must be used. School delays look inevitable and school closures are possible, especially in areas where the main precipitation type is snow. For my Dracut audience, we’re in the main p-type being snow area, if you’re curious. For everyone who is in school (myself included), please do your homework, as there are a number of things that can go wrong with this forecast.
I’ll have more tonight or tomorrow morning.
Have a wonderful day!