Area Forecast Discussion
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FXUS61 KPBZ 301559
Area Forecast Discussion
National Weather Service Pittsburgh PA
1059 AM EST Wed Nov 30 2016
Mild today with showers ahead of an approaching cold front, with
much colder temperatures into the weekend.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Quick update late this morning to make minor adjustments to hourly
temperatures and throughout the day and increase PoPs and winds
along the cold front as it crosses the region tonight.
Prev discussion follows..
Rain beginning to fill in from eastern Ohio and points east a
little more as of 6am. Saturation of the low-levels has been slow,
as a layer of dry air evident on last night`s sounding has delayed
the onset of steadier rain. Warm, moist advection will continue
ahead of the center of the surface low that will advance northeast
up the Ohio Valley today. This will keep rain in the forecast for
most locations through the afternoon, although an abrupt back edge
is evident near Zanesville, OH. Hi-res models handling this back
edge fairly well, bringing it near Pittsburgh by early this
afternoon, before another shortwave trough and associated cold
front returns additional rain showers this afternoon/evening.
The warm advection will push temperatures more than 15 degrees
above average today.
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.SHORT TERM /THURSDAY THROUGH SATURDAY/...
Gradually colder though the period as a mid level trough slowly
moves across eastern Canada. While 850mb temps will fall toward
-7C, low level flow will remain west to southwest into Friday
night, keeping bulk of lake effect snow showers well north of
I-80. A fairly dry column will keep any accumulations in the
ridges and north of I-80 light. Flow may turn a bit northwest
Saturday so have maintained low snow shower chances. Temperatures
will move to average or just below through the period.
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
Dry high pressure will end any snow showers saturday night into
Next fast moving shortwave looks to arrive with mostly rain showers
later Sunday into early Monday.
Models then continue to have trouble with timing of shortwaves and
cold air moving east into mid week, and a blend of models was used
for the latter part of the forecast.
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions will deteriorate to widespread MVFR/local IFR
conditions as low pressure center advances up the Ohio Valley. A
low level jet is progged to result in a brief LLWS potential for
ports S-E of PIT later this morning also before quickly exiting.
Another wave and associated cold front is expected to cross the
area this evening, maintaining the MVFR to local IFR conditions. A
wind shift from S to W is expected with the frontal passage.
Periodic restrictions are possible through the weekend especially
N of I 70 with broad upper troughing and cold W-NW flow.