Area Forecast Discussion
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FXUS61 KPBZ 201525
Area Forecast Discussion
National Weather Service Pittsburgh PA
1125 AM EDT WED JUL 20 2016
Dry and warm weather is expected through tomorrow. Hot and humid
weather with periodic thunderstorm chances are expected Friday
though the weekend.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --No major changes for the late morning update. Previous...High
pressure and should maintain dry and mostly clear conditions
through tonight. Morning PBZ sounding supports highs a few degrees
above seasonal levels, with lows near or just below average
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.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Dry weather as the result of surface high pressure will be re-
enforced by ridging aloft through Thursday. Dewpoints will gradually
increase through the day Thursday as southwest flow develops on the
back side of the surface high. The end result will be an increase in
humidity, making the end of the week warm and muggy. Temperatures
will be above average through the short term period.
Best chance of rain in the short term will come with a weak
disturbance that will pass well north of the area Thursday night
into Friday. This upper-level wave will crest the ridge and attempt
to drive southward, spurred along by a southern waggle of the exit
region of the upper-level jet streak. Most model guidance does
develop at least some qpf over the forecast area through the day
Friday, but fighting to displace the ridge in place, this relatively
weak and dry system will have difficulty producing widespread rain.
Will continue to limit PoPs in the chance category, keeping fairly
close to MOS numbers.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A weak boundary will drift over the southern half portion of the
forecast area by Saturday morning. This will serve as the focus for
rain chances Saturday afternoon, although the forecast currently
calls for mostly dry conditions for the daytime period. Hot and
humid conditions will carry through the weekend, fueling shower and
thunderstorm chances, first along the warm front Sunday and then
with the approaching cold front Monday.
High temperatures over the weekend will be well above average with
many locations pushing above 90 degrees. These temperatures,
combined with dewpoints near 70 degrees will lead to heat indices
into the upper 90s to near 100 in some locations. Temperatures will
moderate some Tuesday and Wednesday in the wake of the departing
cold front. High pressure will re-establish for drier weather for
the middle of next week.
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions and light winds can be expected through the TAF
period as high pressure remains the dominant feature. Fog at
northern TAF locations were not included in the latest TAF
issuance based on latest model soundings, however, it is not out
of the question as there should be slightly stronger radiational
cooling overnight. There will be higher confidence in this later
today after determining this afternoon`s crossover temperatures
and observing dewpoint trends.
.OUTLOOK /WEDNESDAY THROUGH SUNDAY/...
Scattered restrictions in thunderstorms are possible Friday