Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
528 am EDT sun Aug 31 2014
showers and a few thunderstorms today as humid conditions remain.
Near term /through tonight/...
early morning update to adjust probability of precipitation toward radar trends. No other
changes and previous discussion below.
Broad area of showers and isolated thunderstorms into eastern Ohio
and northwest PA will fill in across the remainder of the region
this morning...as shortwave ahead of approaching upper level
trough quickly moves northeast. Cat probability of precipitation today as system
transitions east. Expect a general one half inch to one inch
rainfall with localized higher amounts. Temperatures will be held
down toward seasonal average this afternoon with clouds and
showers. Showers will diminish northwest to southeast tonight as
shortwave exits and upper level trough is sheared out well ahead
of a much deeper upper trough moving into the western Great
Short term /Monday through Wednesday/...
warm and humid Monday in southwest flow aloft...but no real
kicker for convection so chance probability of precipitation maintained with mainly
differential heating acting on low level instability. Fairly
strong cold front and upper through will bring likely probability of precipitation back to
the forecast Tuesday. High pressure will give a dry and seasonal
forecast for Wednesday with somewhat less humidity.
Long term /Wednesday night through Saturday/...
high pressure will remain along the East Coast through Thursday
night...allowing conditions to remain dry. While the 00z GFS keeps
an approaching cold front to the northwest on Friday...European model (ecmwf) and
several ensembles show the front approaching more quickly...and have
sped up timing in forecast. While precipitation coverage will wane
overnight...coverage should increase again on Saturday with fairly
decent model timing this far out. In advance of the cold
front...temperatures will be about five degrees above normal.
Aviation /10z Sunday through Thursday/...
widespread showers and isolated thunderstorms will advance into the
region from the southwest. This will bring MVFR restrictions to all
sites...and IFR conditions cannot be ruled out. Although an isolated
thunderstorm is possible during the morning hours...best chance for
any thunderstorms would be during peak heating this afternoon. Rain
will begin to diminish from northwest to southeast this
evening...but conditions are still expected to remain low MVFR.
Outlook.../Sunday night through Thursday/...
restrictions are possible again with a cold front on Tuesday.