Scientific Forecaster Discussion
fxus61 kpbz 182339
Area forecast discussion
National Weather Service Pittsburgh PA
739 PM EDT Thu Jul 18 2019
heat and humidity will plague the region through the weekend.
Near term /through Friday/...
the early eve update featured the addition of some isolated early eve
thunderstorm potential for the I 77 corridor as outflow from
previous convection with a weak shortwave will encroach on that area
of east.C. Ohio. Otherwise, no major changes were needed for the
forecast of a warm night with increasing humidity.
There is a bit of uncertainty as to how far south showers/storms
will form in reference to a front crossing the Great Lakes on Friday.
The much bigger weather story will be the well advertised heat and
humidity as a result of an upper ridge moving towards the East Coast.
Except for the higher elevations of Preston, Garrett, and Tucker
counties, all locations are under excessive heat warnings or
Short term /Friday night through Sunday/...
the heat and humidity will continue into Saturday, with temperatures
a couple degrees higher on Saturday but dewpoints a couple degrees
lower. The heat advisories/warnings will continue Friday night into
Saturday with apparent temperatures being relatively similar each
day. A cold front will begin crossing the region Sunday, bringing
showers and thunderstorms to all locations.
Long term /Sunday night through Thursday/...
the front will complete its passage of the forecast area Sunday
night, although showers will linger into Monday morning to the south
and east of Pittsburgh. Behind the cold front, high pressure will
dominate the Great Lakes region with much cooler temperature.
Aviation /00z Friday through Tuesday/...
VFR conditions are expected to continue late this evening and just
before sunrise for all sites. With the absence of rain this afternoon
and an increase to the low-level winds, fog is expected to be scarce
during the overnight time period. However, since there is still an
abundant amount of low-level moisture and mid-level subsidence,
clouds are expected to linger near the threshold of MVFR after
09/10z. The confidence of IFR conditions is low, thus the removal
from the previous forecast. VFR conditions will prevail shortly after
sunrise, winds will increase throughout the day due daytime mixing.
the next chc for widespread restrictions will come with an early week
Ohio...excessive heat warning from noon Friday to 8 PM EDT Saturday for
PA...heat advisory from noon Friday to 8 PM EDT Saturday for paz007>009-
WV...excessive heat warning from noon Friday to 8 PM EDT Saturday for
Heat advisory from noon Friday to 8 PM EDT Saturday for wvz021-