Area Forecast Discussion
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FXUS61 KPBZ 271933
Area Forecast Discussion
National Weather Service Pittsburgh PA
333 PM EDT WED JUL 27 2016
Warm with increasing humidity through the weekend. low pressure
moving toward the region will bring increasing shower and
thunderstorm chances later thursday into Friday.
.NEAR TERM /THROUGH THURSDAY/...
Isolated showers have developed near the weak boundary near or
just south of Interstate 70 with peak afternoon heating. Will keep
isolated wording for showers or storms into early evening this
region. Otherwise dry overnight with temperatures near 5 degrees
above the seasonal average.
On Thursday models agree that a shortwave will ride east along the
stalled boundary, with increasing shower and thunderstorm chances
as the afternoon progresses. Best upward omega is progged toward
the southeast ridges where highest pops were forecast.
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
Model differences continue with where highest QPF will reside
with shortwave moving east Thursday night into Friday. Dew points
will be on the rise, with deep moisture also being pulled into
areas south and east of Pittsburgh as boundary moves north. Used
adjusted RFC QPF for the most part, with heaviest rainfall
potential suppressed south and east of the ridges for now. This
will need to be evaluated with time, as rainfall and rainfall
rates may bring the need for a flash flood watch over the
southeast. For now with uncertainty and any event looking to be
well into tomorrow night, did not want to handcuff later shifts
with a watch.
System will slowly exit Friday decreasing POPs northwest
to southeast across the region.
Weak upper level trough with multiple shortwaves crossing the
region will keep shower and thunderstorm chances through Saturday
with humid conditions.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A series of shortwaves moving through the weak trough over the
eastern CONUS will support periodic rain chances and seasonal
temperatures into Monday. A weak bubble of surface high pressure
looks to bring warm temperatures with little chance for showers
Tuesday and Wednesday. A modified Superblend was used for much of
the extended period.
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected through much of tonight with high
pressure over most of the area. Patchy MVFR fog is expected near
dawn Thursday, mainly near a stalled surface boundary south of I
70 where more favorable low level moisture is progged. This should
mix out after dawn, though MVFR CU ceilings are expected in this
same area thereafter.
Approaching low pressure should result in increasing shower and
thunderstorm chances Thursday south of I 80, though much of the
precip should be after the TAF period.
.OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/...
Broad upper troughing should maintain periodic restriction
potential through Monday.