Here is CTP forecast discussion on the Clipper today.
NEAR TERM /THROUGH TONIGHT/...
Focus later today remains on approaching Alberta Clipper, which
is progged to track east along the Mason Dixon Line between
22Z-04Z. Typical of clippers, this system will lack significant
moisture, so expect its associated shield of warm advection snow
to be light. However, model time sections support fairly high
snow/water ratios, with maximum lift occurring within the
dendritic growth zone. Latest mean WPC snow/water ratios are
near 18/1.
RAP 850-700mb fgen fields, which correlate well with the
heaviest snow currently falling over the midwest, indicate the
corridor of steadiest snow will fall along the I-80 corridor
this afternoon into early evening. Latest HREF mean qpf in this
region is around 0.1 inches, supporting a band of around 2
inches of snow along I-80. Orographic enhancement is likely to
result in amounts around 3 inches along the spine of the
Appalachians, but don`t think coverage supports an advisory.
Elsewhere, weaker forcing is indicated over the Lower Susq
Valley, where POPs are significantly lower and any snow accums
will likely be limited to a dusting. As for timing, near term
model guidance indicates the light snow will develop first
across the northwest mountains during the late morning hours,
then rapidly overspread much of central Pa during the early
afternoon.