DAYS 1-5 (JANUARY 29 – FEBRUARY 2)
It’s storm time. All the pre-talk and prep is done. The snow got into the region even a little more quickly than I thought with the help of a frontal boundary sitting just to the south, but also there are signs that the dry air entering the back side of our system also helps shut the snow down a little earlier this evening, so we’re still looking at a just-under-24-hour snow event. But it’s all about what goes on in between the start and end times. As of 2AM, it’s actually raining on Nantucket and outer parts of Cape Cod, but that will change to snow soon as colder air works in. The low pressure area that developed rapidly off the US Southeast Coast last evening will move north northeastward into the vicinity of the 40/70 benchmark during today into this evening, and I’m pretty sure we’ll see this low center have a temporarily elongated configuration, so we’ll have to see if this has any impact on the orientation and movement of the synoptic banding features that will be associated with it. It is under these bands where snowfall rates of 1 1/2 to 3 inches per hour are possible, while most of the time during the peak storm hours, rates of closer to 1/2 to 1 1/2 inch per hour are likely. The snow will be a powdery consistency over most of the area, but will be a little more medium to slightly wetter consistency as you head out through Cape Cod and the islands. It is those areas that would potentially see more in the way of tree limb damage and resultant power outages. I suspect that dry air is going to eat into the back side of the storm and cut the snow off fairly quickly from west to east from about dusk through early evening, which is a little earlier than I was thinking earlier (closer to midnight). Snowflake size will be smaller than what we saw in our recent substantial snowfall, so the “fluff factor” will be a little less. What snow is falling and on the ground will be blowing around quite a bit, hence the blizzard warning for eastern MA, southeastern NH, and RI, where we are most likely to see the criteria met – 3+ hours of visibility 1/4 mile or less due to falling and blowing snow with sustained or frequent wind gusts of 35 MPH or higher. As for accumulation, I left my previous numbers the same which was basically starting with 10-18 inches for everybody, but 18-24 inches occurring in the regions most impacted by the synoptic banding for the longest time. It is also in these bands where thundersnow is possible. Is there the potential for greater than 24 inches? Yes, but I feel this will be more of an isolated occurrence than something that covers a larger area. If somebody gets around 10 inches, that’s most likely be southwestern NH and parts of central MA. Regardless of what falls, the snow will be hard to measure due to the considerable blowing/drifting. There’s no change in the wind expectations, with frequent 30-50 MPH gusts inland and 50-70 MPH in coastal areas, with spot gusts to around 80 MPH in some coastal areas. Coastal flooding concerns will be there for both this morning’s and this evening’s high tides, with east and north facing shores having mostly minor to spotty moderate flooding with the morning high, and north facing shores more vulnerable to some moderate flooding for the evening high, although by then the storm will have peaked and starting to ease, so this will help avoid the worst possible scenario. So that about covers the storm, and I’ll add additional thoughts in the comments section during the day. Not much change to the outlook beyond this. Dry and chilly weather Sunday-Monday to end January, but good for post-storm cleanup. February arrives with a moderating trend and a chance of more unsettled weather as we head toward the middle of next week, but the set-up for the next system indicates rain chances and lots of melting snow. More on that after we get by today’s event.
TODAY / THIS EVENING: Overcast. Snow, heavy at times, tapering off evening. Thundersnow possible. Snow accumulations 10-18 inches with bands of 18-24 inches and spot amounts of greater than 24 inches possible. Blizzard conditions southeastern NH, eastern MA, and RI, ending evening. Pre-dawn temperatures starting out 25-30 northwest of Boston and 30-35 to the southeast to the teens northwest and 20s southeast during the day. Wind chill falling below zero at times especially Boston west and north. Wind NE to N 15-30 MPH with gusts 35-50 MPH inland and 25-40 MPH with gusts 50-70 MPH coast with isolated gusts 75-80 MPH possible.
LATE EVENING / OVERNIGHT: Breaking clouds. Perhaps a snow flurry. Lows 12-19. Wind N to NW 15-30 MPH, higher gusts with strongest in the late evening, diminishing a little overnight. Wind chill often below zero.
SUNDAY: Mostly sunny. Highs 22-29. Wind NW 10-20 MPH, a few higher gusts. Areas of blowing snow at times.
SUNDAY NIGHT: Clear. Lows 2-9. Wind NW diminishing to under 10 MPH.
MONDAY: Sunny. Highs 23-30. Wind variable up to 10 MPH.
MONDAY NIGHT: Partly cloudy. Lows 15-22 evening, rising overnight. Wind S up to 10 MPH.
TUESDAY: Partly sunny. Highs 30-37. Wind SW up to 10 MPH.
TUESDAY NIGHT: Variably cloudy. Temperatures steady or slowly rising. Wind SW 5-15 MPH.
WEDNESDAY: Mostly cloudy. Chance of rain showers afternoon. Highs 40-47. Wind SW 5-15 MPH.
DAYS 6-10 (FEBRUARY 3-7)
Mild with periods of rain or rain showers February 3-4, followed by colder air with dry weather mid period and a snow chance later in the period.
DAYS 11-15 (FEBRUARY 8-12)
Starting out chilly, then milder again. Additional unsettled weather threats.