Scientific Forecaster Discussion
fxus61 kpbz 270411
Area forecast discussion
National Weather Service Pittsburgh PA
1211 am EDT Sat may 27 2017
advancing low pressure will return rain to the region tonight.
Near term /through today/...
a shortwave advancing toward the region and a weakening mesoscale convective system
should spread showers and a few thunderstorms across the region
tonight. Better thunderstorm chances with the weakening mesoscale convective system are
anticipated for areas south of pit as per expectations of
surface warm front progress and resulting instability profiles,
though an isolated tstm mention was included up to I 80 given
elevated expectations on the northern flank of the sfc low.
Improvement is anticipated Saturday as shortwave ridging ensues
in the wake of the night/morning rain. Have thus reduced precip
probs more rapidly than previously indicated, though areas S of
I 70 could see aftn showers/storms where a stalled sfc boundary
is progged. Residual cloud cover should prevent strong
temperature recovery despite rising heights on Saturday.
Overall, readings a few degrees above the averages can be
anticipated for the period.
Short term /tonight through Monday/...
a shortwave crossing the upper Midwest and Great Lakes through
Sunday is forecast to increase rain chances again on Sunday with
the warm surge on the Van of the system. The associated cold
front should support further convection into the night, with
improvement on Monday as high pressure rapidly slides across the
area. Temperatures generally will remain near or just above climatology.
Long term /Monday night through Friday/...
broad upper troughing will develop behind the Sunday cold front,
with that pattern lingering through most of next week. Shortwaves
rotating through the trough will provide occasional chances for
mainly scattered showers. Temperatures will generally remain
near or just below average values.
Aviation /04z Saturday through Wednesday/...
condition deterioration is expected tonight as crossing low
pressure spreads showers and thunderstorms across upper Ohio
Valley terminals. Expect a condition downgrade to eventual low-
end MVFR/LCL IFR, ceilings of which are likely to linger
through much of Saturday morning before shortwave ridging
returns VFR to area ports.
rain and restriction potential will return with Sunday low pressure.