Dangerous cold weather to hit region
By James M. Arnold, Weather Specialist
Region – The storm appears to be pretty much on target for what I expected a few days ago.? While not delivering a blockbuster snowfall, the combination of 8 to 12 inches of snow, strong northeast winds and very?low temperatures will make this a memorable storm.? To simplify my explanation of how this will play out, I will address each hazard class individually.
Snow will begin in the pre-dawn hours?tomorrow, likely in the 2:00 to 4:00 AM time window.? This could be termed “pre-curser” snow, as it is not from the developing and intensifying storm just yet.? This is from a bit of warm air advection, the process of warmer air riding up over the cold surface air.? There might be as much as an inch on the ground for the morning commute, and?occasional light snow will fall throughout the day.? There is even the chance that it will break off for a few hours around mid day, then?begin again during the afternoon.? This will become steadier and heavier by evening, and snow will become moderate by the end of the evening commute with about 3 or 4 inches possible by 8:00 PM tomorrow.? Steady light to moderate snow will continue throughout the night and into Friday morning before tapering off and ending around noon.? By the time it ends, there should be about 10 to 12 inches on the ground across our entire area.? If there is a wild card in all this, it is where?a coastal front sets up and contributes to some enhancement of snowfall.? This should be somewhat to our east, but I don’t know exactly where this will happen if it happens at all.
Wind will not be an issue tomorrow, but as evening approaches and we come under the circulation of the storm system, north to northeast winds will begin to increase.? They will reach speeds of 15 to 25 mph with gusts to 30 to 35 mph by midnight and continue into Friday morning before shifting to the northwest and continuing at those speeds throughout the day.? Winds will begin to diminish after midnight Friday, but will still be blowing at 10 to 15 mph by Saturday morning.? Extreme wind chill values?are described below.? With the extreme cold, this?snow will be very fluffy and powdery and will be blown around by these winds.? There will be a lot of blowing and drifting of the snow and there could be some drifts reaching 3 feet in scattered areas.? Blowing snow will also hamper travel by?reducing visibility throughout the storm.
Overnight tonight our temperature will fall into the low to mid teens and not recover all that much tomorrow, perhaps reaching the low 20s Thursday afternoon.? By late tomorrow when the circulation of the ocean storm reaches our area, temperatures will slowly fall through the teens overnight reaching the single numbers by Friday morning.? There will be little or no temperature rise Friday and by nightfall it could be approaching 0 degrees.? Temperatures will fall throughout?Friday night reaching the lowest levels of the winter so far, at about 8 to 12 degrees below zero by Saturday morning.? Wind chill values will be extreme at times.? During the day on Friday, wind chills will reach -15 to -20 degrees at times.? Friday night wind chills?could?reach -35 to -40?degrees! ? The extreme cold will begin to relax on Saturday.
The next system to impact our area should arrive late Sunday or early Monday.? Right now there are conflicting signals as to what it will be, but it will not be as cold as the current storm.? We may see a period of freezing rain transition to a wintry mix of precipitation, possibly changing to all rain before it ends.? This is a long way out and a lot can change?before we get to that storm.
James M. Arnold is a Weather Specialist working with Shrewsbury Emergency Management Agency; town of Princeton; Worcester Emergency Communications and Emergency Management Agency; Southborough Emergency Management Agency; town of Grafton and Wachusett Mountain Ski Area
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