DAYS 1-5 (DECEMBER 22-26)
The previously-prognosticated active pattern with no big storms is ongoing. Keep in mind that when I mentioned this pattern many days ago, I also told you that we could not provide details for timing and impacts of any systems that far in advance, but now in the 5-day period we can elaborate more. We start with a grazing by an offshore storm system today which will be moving rapidly northeastward. Though the center will be quite a distance to our southeast, its precipitation shield is large enough that it will produce a period of rain for several hours this morning. However, surface temperatures will be cold enough over the interior areas, especially west of the I-95 belt, that the rain will be freezing on untreated surfaces, making it slippery for travel. This will have some impact on the morning commute. The good news is that not only does the precipitation exit by midday, but the temperature climbs above freezing in all areas so that any ice will melt. We’ll also see clearing with dry air and increasing wind as the day goes on, which will dry off any surface so that we don’t see any re-freezing tonight. High pressure will bring dry and seasonably cold weather on Thursday. Once we get to Friday and Saturday, Christmas Eve and Christmas Day, we will see a couple of disturbances moving east southeastward across our area. This will be the broken up remnants of a low pressure and frontal system that will be blocked from cleanly passing through the northeastern US by high pressure in eastern Canada. With enough cold air around, we may see some festive snowflakes for at least parts of the region from these systems, with no significant impact expected for travel. Model guidance is not handling the second half of the weekend well, with different models showing different outcomes. Right now it looks like a lingering disturbance passing through on Sunday will produce some scattered snow showers, but some fine-tuning of this part of the forecast will still be needed.
TODAY: Cloudy morning with a period of rain except pockets of freezing rain west of I-95. Gradual clearing afternoon. Highs 39-44 except 45-50 South Shore through South Coast of MA. Wind NE 5-15 MPH morning, NW 10-20 MPH with higher gusts afternoon.
TONIGHT: Clear. Lows 22-29. Wind NW 5-15 MPH, higher gusts.
THURSDAY: Mostly sunny. Highs 35-42. Wind NW 5-15 MPH, higher gusts.
THURSDAY NIGHT: Increasing clouds. Chance of light snow overnight. Lows 23-30. Wind variable up to 10 MPH.
FRIDAY (CHRISTMAS EVE): Cloudy with a chance of light snow morning. Variably cloudy with a chance of snow showers afternoon. Highs 33-40. Wind variable up to 10 MPH.
FRIDAY NIGHT: Mostly cloudy. Chance of light snow late evening and overnight except rain/mix South Coast. Lows 28-35. Wind variable up to 10 MPH.
SATURDAY (CHRISTMAS DAY): Cloudy. Periods of light snow/mix except mix/rain South Coast. Highs 35-42. Wind variable 5-15 MPH.
SATURDAY NIGHT: Mostly cloudy. Chance of mix/snow showers. Lows 28-35. Wind N 5-15 MPH.
SUNDAY: Variably cloudy. Chance of snow showers. Highs 35-42. Wind N-NW 10-20 MPH and gusty.
DAYS 6-10 (DECEMBER 27-31)
Temperatures variable averaging near normal. At least once disturbance brings a precipitation opportunity favoring mid period.
DAYS 11-15 (JANUARY 1-5)
Variable temperatures, averaging close to normal. One or two disturbances may bring precipitation threats.