Forecast discussion: I usually send the forecasts during the evening hours. However, with the computer models forecasting even higher snow totals than last night’s runs, and a day off from my day job, I had the opportunity to give a rare late afternoon update.
At this time, the low is beginning to strengthen off the coast of Delaware. Radar imagery shows Rhode Island is seeing light to moderate snow throughout the state, with the snow shield working into New Bedford. The Winter Storm Warning is already in effect, and will end at 1 p.m. Wednesday afternoon. For Plymouth County, the Cape, and the Islands, a Blizzard Warning is in effect at this time. Already, many after school activities and evening meetings have been cancelled, and parking bans are or will be in effect. For this information, and for any school closings on Wednesday morning, click here.
The only change to the forecast since last night is the snowfall totals. With colder temperatures, the old ratio of 10 inches of snow to 1 inch of rain has increased to about 15 to 1. The reason for the higher ratio is the colder the air, the less moisture the atmosphere can hold. We will see light to moderate snow during the afternoon, but it will pick up in intensity by the start of the evening commute.
As we go through the evening, we will begin to see the full effects of the storm. Winds will be increasing, causing blowing and drifting snow. Snowfall will be increasing, and at some areas, may see one to two inches an hour. This will cause travel to become treacherous, so please be extremely cautious. For the coastline, it will be the winds. Winds will be as high as 40 mph, and gusting to 60 mph. Power outages are very possible, but coastal flooding will be minimal, as winds are coming from the north and north-northwest, and not from the northeast. However, we will still see blowing and drifting snow into the afternoon, until the low pressure center kicks out into the Gulf of Maine later in the afternoon.
So, for the Boston area, I am seeing about 6-10 inches when we wake up by Wednesday morning. For Plymouth County, I am seeing about 10-15 inches. For the Cape and Islands, I am seeing a total of 12-18 inches. Due to the ocean effect snow showers, the Cape and Islands will continue to see snow showers right into early Wednesday evening. This area will see another 2-4 inches of snow on Wednesday alone.
After Wednesday night, the next obstacle will be the bitter cold. Thanks to the fresh snowpack, any sunshine we receive will be kicked back into the sky. So, high temperatures will only remain in the upper teens. Overnight lows will remain above zero, but I am only expecting the lower single digits. Any wind during the night will create wind chills around 5 to 10 below zero. So, make sure you do not keep any exposed skin for long periods of time, if you have to work outside during this time.
Temperatures will become milder as we head into Saturday, with daytime highs in the lower 30’s. But, a quick moving low pressure system will bring some more light snow by Saturday evening. The snowfall will be much lighter, and will end by Sunday morning. Another low, an Alberta Clipper, will bring the chance of more snow showers during the daytime hours on Monday. High pressure will control the eastern U.S. on Tuesday, giving us limited sunshine, but temperatures will remain well below normal.
72 hour forecast:
Rest of afternoon: Light snow overspreading the area, with steadier snowfall by the evening commute. One to two inches will be on the ground by 5 p.m.
Tonight: Moderate to heavy snow, strong winds, and cold. Zero visibility in drifting and blowing snow, especially along the Cape and Islands. We will see a low of 13.
Wednesday: Light to moderate snow diminishes through the morning, before ending by 1 p.m. We will see a high of 17. Winds will come from the north-northwest at 18-23 with gusts of 35 mph while diminishing through the afternoon. So, expect blowing and drifting snow to continue. I’m expecting 6-10 inches within the Boston region, with the rest of the state seeing 10-15 inches. Wind chills will be 0 to 5 below zero. The Cape and Island will see snow showers throughout the day, with 12-18 inches by early Wednesday evening.
Wednesday night: Partly cloudy and bitterly cold with a low of 3. Winds will come from the northwest at 6-9 mph. Wind chills will be 5 to 10 below zero.
Thursday: Partly to mostly sunny with a high of 17.
Thursday night: Mostly cloudy with a low of 4.
Friday: Snow showers around the Cape and Islands in the morning; otherwise, mostly sunny skies. We will see a high of 16.
Friday night: Partly to mostly cloudy and warmer with a low of 11.
Saturday: Mostly cloudy with light snow by the early evening. Highs 31-34, lows 16-19.
Sunday: Snow showers end in the morning, with partly to mostly sunny skies. Highs 24-27, lows 15-18.
Monday: Mostly cloudy with snow showers by dawn, ending in the late afternoon. Highs 25-28, lows 11-14.
Tuesday: Partly sunny. Highs 21-24, lows 12-15.