Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Pittsburgh PA
1249 am EST Sat Nov 28 2015
occasional rain showers are expected at any time through late
tonight. Will dry out and cool down Sunday before showers return
Near term /through today/...
overnight period will deal with trying to time and pinpoint rain
showers. Expect shower coverage to increase later tonight as the
next shortwave rides north along the sagging frontal boundary. It
is the lack of large scale Ascension that is limiting shower
activity. Temperatures have been modified with the latest hires
Front will drift south of the area this morning and eventually
stall over the northern reaches of the middle-Atlantic region. A
series of upper level disturbance will streak north of the front
today in the zonal flow aloft. These crossing impulses will keep
in showers for much of the day with an eventual shift to the south
by late afternoon. With this setup...do not think it will be
raining constantly all day...but there will be periods of more
steady rain from time to time.
Cooler air will eventually settle in over the area...so
temperatures will move closer to seasonal levels.
Short term /tonight through Monday/...
higher probability of precipitation are focused over the southern half of the area tonight
with a slow progression toward the Mason-Dixon line. Timing
between models still remains an issue...but it appears that most
areas over the south should see showers ending around dawn Sunday.
Far southeastern counties will have to wait a bit longer for the
showers to clear...as one final shortwave swings through.
Temperatures will be a bit cooler Sunday.
On Monday...digging low pressure over the Central Plains is
expected to push warmer air and moisture back over the region.
Probability of precipitation were increased from south to north through the day.
Long term /Monday night through Friday/...
showers will have overspread the entire region by Monday night as
the deep system moves toward the western Great Lakes. It will
take until Tuesday evening for the occluded front to swing through.
Precipitation...wrapping around the exiting system...is possible
late Tuesday night and through much of Wednesday. Noticeably
colder air will accompany the wrap around activity.
Area should dry out Thursday and Friday...as broad high pressure
moves in from the west. Temperatures will remain near normal for
Aviation /06z Saturday through Wednesday/...
a cold front will slowly sink southward across the region today.
Duj/fkl are already at IFR/LIFR...and expect the rest of the
terminals to follow suit with time as abundant low level moisture
becomes established. Once it arrives...IFR or worse ceilings will be
maintained for most of the taf period...even as rain showers slowly come
to an end during the afternoon and evening. Fkl/duj may briefly
achieve MVFR during the afternoon as those locations may see a
slight moisture decrease further behind the front. However...with
nocturnal cooling...IFR should return during the evening.
Outlook...Saturday night through Wednesday/...
low pressure will return restriction chances late Monday through