Scientific Forecaster Discussion
fxus61 kpbz 270944 cca
Area forecast discussion...corrected
National Weather Service Pittsburgh PA
544 am EDT Sat may 27 2017
areas of crossing low pressure will result in periodic shower
chances through early Monday.
Near term /until 6 PM this evening/...
a crossing shortwave and weakened mesoscale convective system should maintain showers
across the region through early morning. Meso analysis shows
elevated instability exists S of pit, so maintained the isolated
thunderstorm mention in that area. Improvement is expected later
today as shortwave ridging ensues in the wake of the showers.
Areas S of I 70 could see isold/sct aftn showers/storms
redevelop in proximity to a a stalled sfc boundary. Storm Prediction Center
outlooks have areas S of the PA/WV border in a slight risk for
severe storms, though warmth aloft and limited daytime heating
should limit this potential. Better chances continue farther S
of the boundary. Temperatures should average near or a few
degrees above the seasonal levels.
Short term /6 PM this evening through Monday night/...
a shortwave crossing the upper Midwest and Great Lakes ahead of
an approaching surface low is forecast to increase
shower/thunderstorm chances again on Sunday. The low's associated
cold front should support further showers/storms into the
night, with improvement on Monday as high pressure ridging
rapidly slides across the area. Temperatures generally will
remain just above the seasonal levels.
Long term /Tuesday through Friday/...
broad upper troughing is progged across the NE Continental U.S. And Great
Lakes region through the period. Shortwaves rotating through
the trough will provide occasional shower chances through mid
week until surface high pressure builds under the trough by late
week. Temperatures should average near to a few degrees below
Aviation /10z Saturday through Wednesday/...
an area of showers with a few isolated storms will continue to
cross the area and be east of duj by mid-morning. Thus far
downstream locations have remained largely VFR during during
showers...and would expect that to continue based on latest
forecast soundings. This afternoon there is a slight chance of
shower/storm development at mgw but farther north conditions
will be too stable with the ridge axis over the forecast area.
rain and restriction potential will return with Sunday low pressure.