Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
655 PM EST Thursday Mar 5 2015
high pressure will buiild in through Friday. A weak cold front is
expected late Saturday.
Near term /through Friday/...
minor tweaks to sky cover for the early evening update.
Previous...snow has just about exited the County Warning Area to the east as deep
moisture is shunted out by shortwave moving across the Great
Lakes. Surface high pressure noses in tonight...and the resultant
anticyclonic flow will allow skies to clear this evening. Cannot
rule out a few low clouds hanging around in the zzv vicinity as
BUFKIT soundings suggest lingering moisture...but most areas will
clear out. Winds will slacken as well...which will allow for rare
March below zero temperatures in many areas. See climate section
for record lows in jeopardy. With Garrett County holding on to a
bit of wind overnight...will go ahead and issue a Wind Chill
Advisory as it will not take much to get apparent temperatures down below
Friday will be dry with plenty of sun...although expect some
afternoon instability cumulus to pop. H850 winds turn southwest by the
end of the day...but with temperatures at that level hovering around
-13...plus the snowpack...still expecting high temperatures in the lower
to middle 20s. Cl
Short term /Friday night through Sunday/...
surface high heads east Friday night. The northeast U.S. Remains
in a persistent but flatter trough aloft. A couple of fairly weak
impulses drop through the northwest flow this weekend. The first arrives
Saturday and lingers into the following evening...and the second
moves in Sunday night. Not particularly impressed with quantitative precipitation forecast
potential from either system given their northern origins and
therefore lesser moisture content. Still think chance probability of precipitation look
appropriate for mainly areas east of Ohio Saturday/Saturday night.
Most precipitation will fall as snow...but a little rain may mix in along
the southern periphery of the precipitation during Saturday afternoon.
Any potential snow accumulation looks quite light. Sunday will
feature a lull in activity...before the next approaches late
Sunday night. Temperatures will be above freezing by day and below
by night...exactly what is needed for a slow and controlled melt. Cl
Long term /Sunday night through Thursday/...
the extended period looks to be relatively quiet as zonal flow
sets up across the forecast area and we see a gradual warming
trend in temperatures...extending slightly above normal by
midweek. A shortwave will brush by to the north on Monday but with
limited moisture and weak dynamics...the best chance for any
precipitation will be mainly limited to locations along and north
of Interstate 80. Models show a similar setup by midweek...but
again expect minimal impacts as energy will be too far north.
Adjustments to the extended were based mainly on a blend of ec and
Aviation /00z Friday through Tuesday/...
mainly VFR conditions are expected through Friday as middle level
clouds clear under building high pressure. Cumulus rule indicates just
some scattered diurnal cumulus Friday afternoon.
Outlook.../Friday night through Tuesday/...
restrictions are possible with a weak Saturday cold front.
a Flood Advisory continues for the Ohio River at the point in
Pittsburgh...and river flood warnings continue for Charleroi and
Elizabeth on the Monongahela river. Crests have already occurred
at these points...and levels will continue to fall tonight.
Pittsburgh record low on Thursday March 5...8 set in 1926.
Morgantown record low on Thursday March 5...8 set in 1960.
Zanesville record low on Thursday March 5...2 set in 1978.
Pittsburgh record low on Friday March 6...2 set in 1901.
Morgantown record low on Friday March 6...12 set in
Zanesville record low on Friday March 6...5 set in 1960.
Maryland...Wind Chill Advisory until 9 am EST Friday for mdz001.