Area Forecast Discussion
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FXUS61 KPBZ 210104
Area Forecast Discussion
National Weather Service Pittsburgh PA
904 PM EDT Sat Aug 20 2016
Showers and possible thunderstorms are expected with the approach
and passage of a cold front through early Sunday, before building
high pressure brings dry and less humid weather through mid week.
.NEAR TERM /THROUGH SUNDAY/...
-- Changed Discussion --Shower chances are expected to increase through the night with
increasing shortwave support ahead of an approaching cold front.
With waning instability maintained only a chance of thunderstorms.
Passage of the front is progged for late night/early Sunday
morning, so maintained a period of high likely to categorical
pops with it`s passage with sufficient moisture and shortwave
The front is expected to exit from W-E Sunday morning with a
corresponding reduction in pops. Lows should average around 10
degrees above seasonal levels tonight, with readings close to
average Sunday after frontal passage.
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.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
The 500 mb trough axis will push through Sunday night. Northwest
flow off of the Great Lakes and modest cold advection may promote
a few isolated showers overnight north of Pittsburgh. These will
end by sunrise, with lower dewpoint air moving in.
Monday and Tuesday will feature abundant sunshine and comfortable
humidity levels as surface high pressure crosses. Below normal
temperatures on Monday will rise closer to climatology on Tuesday
as the air mass modifies and mid-level heights rise.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Dry weather continues through Wednesday with the passage of the
mid-level trough axis, and temperatures will warm to above normal.
Humidity increases again by Thursday in increasing southwesterly
flow. Shower and thunderstorm chances return by Thursday night
ahead of the next front. The boundary passes Friday or Friday
night with continued rain chances. Behind the front, dry weather
and seasonable temperatures are forecast for the start of the next
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Medium confidence forecast. A cold front will cross around daybreak
spreading showers and perhaps a rumble or two of thunder to all
terminals late tonight through the overnight. The period of time
when a restriction in showers is forecast continues to decrease
with subsequent model runs. Continued MVFR VIS restrictions with a
period of IFR cigs at most terminals in wake of the front /11z-
15z/. This concurs with what happened this morning over IA and IL.
Low level moisture hangs tough through the morning hours before
owing to cirrus clouds from west to east during the afternoon.
Several terminals will be just below IFR threshold...however
despite guidance putting all airports below 1K opted to keep the
more climo favored ones /PIT, LBE, and MGW/ just above.
Winds will be from the south to southwest before turning to the
west. Speeds will be around 10 kts the duration of the forecast.
.OUTLOOK /SUNDAY NIGHT THROUGH THURSDAY/...
The next chance for restrictions will be early Monday with MVFR
fog and stratus.