A deepening trough across the Northern Plains Thursday will track
east while low pressure crosses the Great Lakes Thursday night into
Friday. Initially, a warm front will move across the region late
Thursday night into Friday morning with temperatures climbing to the
upper 30s to low 40s in most places but right in the morning.
Moisture will be increasing across the region and rain and snow
showers will move into western NY late Thursday night. Can`t rule
out some sleet or freezing rain at the onset with a cold ground and
warmer air moving in aloft. It will be a quick warm-up as a strong
cold front quickly moves into the region Friday morning. Any
precipitation will change over to snow by Friday evening.
Temperatures at 850mb will fall to -15C Friday night. Abundant
moisture with a trough overhead and cold, southwest flow will result
in lake effect snow forming behind the front Friday night into
Saturday morning. Localized accumulating snow is likely.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
Initial return of colder air pours across the region Saturday in the
wake of the cold front that crossed the area, then stalled out just
to our southeast. 850Ts in the minus mid teens will bring the
possibility for some lake snows east of the Lakes Saturday. A weak
area of low pressure will then ride northeast along the stalled
boundary, introducing a good deal of shear, thus weakening any
lingering lake effect Saturday night, however will bring a general
chance of snow showers to the region as it moves through.
This same area of low pressure will move north of the area on
Sunday. As it does so, it will drag a trailing cold front across the
region, opening the door for a large area of true arctic air (850Ts
diving below -20C, possibly much lower??) poised over the upper
Great Lakes/Central Canada to pour across the Northeast and Mid
Atlantic region. This will likely set the stage for our next round
of potentially significant lake snows. However, it`s way to early to
get into the details, but will be something to watch. The other big
story here will be the brutally cold air that will encompass the
region by later in the weekend into the start of the new work week.