Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
713 PM EST Thursday Nov 27 2014
cold northwest flow will keep scattered snow showers across the
region tonight. High pressure will bring dry and chilly
conditions Friday. A warming trend is predicted this weekend as
reading rebound into the 50s come Sunday.
Near term /through Friday/...
update issued to hoist a Winter Weather Advisory for Garrett and
Tucker counties for snowfall overnight. Recent reports confirm
three inches for Tucker County and the higher elevations of
Preston. So far in Garrett up to two inches of new snow has
fallen. Elected to keep Preston out of the advisory since criteria
/three inches or more in 12 hours/ will be confined to the higher
peaks in the southeastern part of the County.
Previous discussion below...
a line of snow showers is about to exit the eastern part of the
forecast area associated with the middle level DCVA. Snow dynamics
are favorable with layered Omega coinciding in the dendrictic
growth layer with plenty of moisture in the column. Snow ratios
will climb from the middle teens to lower 20s overnight. One thing
we will be watching is a possible band of snow coming off Lake
Erie during the middle to late evening hours which is illustrated by
the hrrr...ruc13...and 18z nam12. This band while will not produce
a lot of snow...however Road could be covered with up to an inch.
Updated probability of precipitation to increase numbers over much of PA to
likely...while bumping up the mountains to categorical. So far three
inches of snow has fallen in the highest peaks in Preston County.
Snow totals were maintained for the large part with a slight
upward adjustment over the I-80 corridor to account for increasing
snow ratios this evening.
Short term /Friday night through Sunday/...
southwest low level flow will develop Friday night into Saturday
with upper level flow becoming more zonal. A shortwave and warm
advection will bring clouds and possibly a bit of light snow early
Saturday north of Pittsburgh. Temperatures will warm dramatically
Saturday night and Sunday ahead of an approaching upper trough and
cold front. Low level moisture will increase ahead of the front
allowing for scattered rain showers Saturday night and Sunday.
Temperatures will warm to over +5 at 850mb Sunday afternoon with
maximum temperatures well into the 50s Sunday.
Long term /Sunday night through Thursday/...
front will clear the area early Monday morning. Showers will end
but temperatures will cool down on Monday. Seasonable temperatures middle
week with the next disturbance and cold front arriving late
Tuesday and Wednesday.
Aviation /00z Friday through Tuesday/...
one round of snow around sunset has moved through all
terminals...but a band of snow has moved inland from Lake Erie as
of 00z and will make its way to the southeast. Expect this line
to affect all Pittsburgh metropolitan area terminals. In
addition...occasional snow is expected to continue at fkl/duj
through the evening hours. All snow should diminsh by sunrise.
Winds will back to the west- southwest for Friday with VFR
Outlook.../Friday night through Tuesday/...
restrictions will be possible Friday night at fkl/duj with a
system moving north of the region. The next chance for widespread
restrictions will be Sunday with the passage of a cold front.
Maryland...Winter Weather Advisory until 7 am EST Friday for mdz001.
WV...Winter Weather Advisory until 7 am EST Friday for wvz041.