Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
426 am EST Friday Mar 7 2014
moderating temperatures will continue into Saturday. A weak cold
front will cause precipitation late Saturday through early Sunday.
Near term /until 6 PM this evening/...
slow warm air advection today as upper level ridge builds over the Midwest and
high pressure moves into the Tennessee Valley behind exiting coastal low.
Expect a good deal of sunshine today...which will assist in
pushing temperatures to near normal levels.
Short term /6 PM this evening through Sunday night/...
a weak cold front will sag through the area Saturday afternoon.
Moisture and upper level support will be lacking with the boundary
itself. Models are still not sure how much precipitation to develop with
the front and what time to develop it. It appears they are coming
into better agreement that the activity will be behind the
boundary with the shortwave trough and colder air. Will keep probability of precipitation
in the chance Cat with most of the activity moving through Sat night.
Warmer air ahead of the upper level wave will allow for rain
initially...which will slowly change to snow as the colder air
aloft drifts southward. Shortwave will swing through quickly...
so expect the precipitation to end by dawn Sunday.
High pressure and colder air will settle in on Sunday. But this
brief intrusion of cold air will be short lived...exiting to the
east by Sunday afternoon.
Long term /Monday through Thursday/...
long term will remains quiet until the middle of next week. Models
are still trying to figure out what to do with the interaction
between a cold front that crosses Tuesday night and low pressure
developing south of the front Wednesday. Ensembles and latest GFS seem
to be in okay agreement...showing the front and low well south of
the area. They are also indicating an open wave with only minor
intensification. At this time...the cold airs March southward will
be held at Bay as the surface low moves eastward through NC/VA.
This would mean rain showers over the south...snow showers north.
The heaviest precipitation would be south and east of the area closer to
the surface low.
Colder air will settle back in by the end of the long term.
Aviation /10z Friday through Tuesday/...
VFR will continue through the taf period with only a few cirrus at
times. East winds overnight into midday will become south under
Outlook.../Friday night through Tuesday/...
the next chance for restrictions will come with a Saturday cold front.