Quantitative Precipitation Forecast Discussion
NWS Weather Prediction Center College Park MD
212 PM EDT Tue Mar 13 2018


Prelim Day 1 QPF Discussion
Valid Mar 14/0000 UTC thru Mar 15/0000 UTC
Reference AWIPS Graphics under...Precip Accum - 24hr


Day 1

New England---northern to western NY state---eastern Great Lakes
into the central to southern Appalachians

The rapidly deepening winter storm off the southeast New England
coast this afternoon will reach its lowest pressure near the
beginning of the upcoming day 1 time period---weakening after this
into the day on Wednesday as it pushes across Nova Scotia---P.E.I.
and New Brunswick.  The emphasis for the heaviest snows in the
well defined comma head/deformation precip band will be shifting
northward at the beginning of the day 1 period into primarily
northern NY state into northern New England from northern
VT---northern NH into much of the state of ME.  Model qpf
solutions are tightly clustered across these areas---supporting
heavy snow potential in the 6-12"+ range. 

To the west of the primary deformation precip band---the upstream
closed low will be sinking east southeastward from the lower lakes
into the northern Mid Atlantic and into southern New England.  In
the wake of this system---the west northwesterly low level flow
off of lakes Erie and Ontario will be strengthening.  This will
support lake effect/lake enhanced heavy snow potential from far
northern OH---northwestern PA into western NY to the south of lake
Ontario and east of lake Erie. 

Lighter snows expected southward into the central to southern
Appalachians in a region of persistent northwesterly to westerly
upslope flow.

See the latest qpfhsd for additional winter weather information
across these areas.

California---Great Basin---northern Rockies---Pacific Northwest

A series of height falls expected to rotate through the base of
the full latitude mid to upper level trof off the west coast day
1.  The lead area of height falls will push inland this evening
through California into the southwest--across the Great Basin and
into the northern Rockies.  This will push the primary frontal
boundary and axis of much above average pw values inland across
these areas.  This will be followed by additional post frontal
height falls rotating inland into northern to central California
during the day on Wednesday.  The net effect will be to support a
rather large area of moderate to locally heavy precip totals.  The
best chance of heavy precip will be through the Sierra where the
greatest upslope flow is expected. Areal average 1-2"+ totals
expected in the Sierra with generally .10-.25"+ totals elsewhere
from the Pacific Northwest---northern Rockies---through the Great
Basin and across the remainder of California.

Oravec