Hey, hey! It’s time to get excited about a bit of snow for the weekend. This is not going to be some early season freak storm, but any snow this time of year moves the needle.
I alluded to this “event” last weekend on ilsnow Facebook and it’s had good ensemble support for a while now. I’ll break this down, then give you an update on the Siberian snow cover.
Weekend Snow!
As Friday’s “St. Lawrence Clipper” moves away, the Canadian floodgates will open. By Saturday afternoon, the clipper (L) will be long gone. But look at the small disturbance (X) moving into western NY:
Temperatures should be in the 40s for much of Upstate New York mid-day Saturday, which means rain showers for most. Snow would be restricted to the highest elevations.
But as that disturbance pivots through the region and temperatures drop, many places will have snow showers through Saturday night. Temperatures will fall to the upper 20s to lower 30s by early Sunday:
With strong directional wind shear, I don’t expect a significant lake effect snow event. But, the mountaintops will be plastered white over the weekend and many other places could get a frosting of snow by Sunday morning.
Sunday will bear the brunt of the chill with temperatures perhaps hard pressed to make it out the 30s in the heart of the Adirondacks. That wouldn’t be totally unusual for October 18th, but it is notable cold, especially since we hit 70*F on Columbus Day!
Of course, that kind of cold doesn’t stick around for long this time of year and temperatures will rapidly moderate next week. But it’s certainly nice to have a nice little cold jolt in mid-October!
Siberian-Eurasian Snow Cover:
Eurasian snow cover is very healthy in the west, but lacking a bit in the east:
As a refresher, the purple areas show where snow pack is ahead of climatological schedule and the red indicates bare areas that should be covered with snow.
The ensembles show potential for rapid snow cover expansion in eastern Siberia under a piece of the polar vortex (PV):
The area of high pressure near the North Pole is a classic negative-phase Arctic Oscillation (AO-) signature that displaces the polar vortices southward and allows for rapid expansion of snow cover.
I discussed the importance of rapid expansion of Siberian snow pack in my Winter Outlook last week.
Notwithstanding El Niño, I’m encouraged by how the overall hemispheric pattern has been setting up in October.
We’ll see what happens as autumn progresses!
For the ilsnow nation,
Darrin
