Capping off an areawide 2-6″ snowfall Thursday morning was a period of lighter mixed precip through the afternoon. It’s Thursday evening as I’m typing up this blog post, and now, it’s freezing rain and sleet taking center stage with an icy buildup underway. Here we go…
Tonight – Freezing rain or drizzle overnight through much of our region thanks to a layer of warmer, drier air aloft will leave an icy glaze by daybreak. Along the Canadian border, through the northernmost tier of counties in New York and Vermont, we’ll stick with light on-and-off snow that could total a fresh dusting to 1-2″ by Friday morning; perhaps with some sleet mixing in, at times. Any overnight snow would max out at 3-6″ in the St. Lawrence River Valley. The temp holds relatively steady, but may bounce between the 20s and 30s.
Interesting little fact…as of 9 PM it’s 32° on top of Mt. Washington, but 22° in Burlington. Hello warmer air aloft!
Friday Morning – After a period of time where wintry mixed precip may lighten early Friday, an air mass that’s much more saturated takes over from that drier slot. This, as an area of low pressure moves up the coast, but a tad inland. Simultaneously, we see a zone of frontogenetic forcing over the St. Lawrence River Valley. Now, what does that mean?? Frontogenesis…The genesis of a front…a boundary between two air masses becoming stronger and better defined. The warmer air mass, the one overtop of us now, gets shoved out in favor of that colder air locked away to the northwest of this developing front. Here’s where we get that transition from sleet and/or freezing rain, to snow…heavy snow.
Friday Midday – Precip will change from west to east, starting in the St. Lawrence River Valley, to snow. Along the zone of frontogenesis, that snow could be quite heavy with rates of 1-2″ per hour. We stick with that heavy snow longest in New York to northwestern Vermont, including the Champlain Islands, northern Chittenden County and Franklin county. Therefore, you’ll see the largest and most impressive snow totals here. Along and southeast of a line from St. Johnsbury to Montpelier to Middlebury, we spend all morning and even midday with mixed wintry precipitation, including freezing rain. Up to 0.25″ ice accretion could be attainable, especially through higher terrain.
Friday Afternoon – By mid to late afternoon, the cold air will have won the battle of air masses, leaving us with snow across the board. Almost as quickly as that happens, however, snow rates lessen and accumulation eases up. This will leave us with a huge disparity in snow totals. You know the joke about the meteorologist who predicts anywhere from 1″ to 24″ of snow? Yeah, that’s me. And it’s, no joke. The temp will hold steady in the morning in the 20s or low 30s, then plummets throughout the afternoon as Arctic air drops south. A gusty northwest wind kicks up, too, at 10-20 mph with gusts to more than 30 mph. With the combination of wind, ice and snow, there will likely be scattered power outages.
Friday Night – Snow rates decrease and snow ratios increase, meaning the snow becomes less slushy and sticky and more powdery. Snow will retreat entirely into the mountains by early Saturday as our temp bottoms out in the single digits above and below zero.
Saturday – Clouds slowly decrease as the temp stalls in the upper single digits to mid teens. Northwest wind 5-10 mph.
Saturday Night – Mostly clear, calmer and cold. Single and double digits below zero.
Sunday – Mostly sunny. Mid to upper 20s. Light south wind.
Have a great Friday! Stay safe!
-Skytracker Chief Meteorologist Amanda Thibault