.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
High pressure will build ewd from MI in the wake of the daytime
wave. Modest potential for light lake-enhanced snow showers to the
north of I-80 lingers this evening for a few hours before dry air and
subsidence erode any remaining CAPE. High pressure will remain
dominant through Tue eve as a strong low develops in the Plains.
As this Plains low advances ewd toward the Ohio Valley, coastal low
pressure will strengthen considerably as an upper-level jet advances
ewd. Strong upward motion associated with the left exit region of
this jet/possible pairing with a secondary jet's right entrance
region will favor high precipitation rates Wed afternoon and early
eve, especially across the sern half of the forecast area.
While precipitation rates will be high and vertical motion will be
strong through the dendritic growth zone, increasing warmth aloft
and sfc temperature in the 32-34F range will reduce snow ratios a
bit, leading to a heavy, wet snow. The highest totals will occur se
of a line from DUJ-CKB, where upward motion will be maximized and
terrain will facilitate colder low-level temp.
There will be a sharp gradient in higher totals nw from this axis,
but snow is expected in all locales at some point on Wed aftn.
A Winter Storm Watch is in effect for Wed/Wed night focused
especially on the ridge zones, where highest totals and impactful
heavy, wet snow are expected. An advisory likely will be needed
adjacent to these zones, which will be highlighted in the HWO.