Area Forecast Discussion
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FXUS61 KPBZ 252233 AAA
Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
633 PM EDT Sat Mar 25 2017
Well above normal temperatures will continue into next week.
Showers with a chance of thunderstorms are expected Sunday
afternoon into Sunday night.
.NEAR TERM /THROUGH SUNDAY/...
-- Changed Discussion --No major changes needed with this update. Modest adjustments
were made next 24 hours to PoPs to add detail based on hi-res
model timing of ongoing showers and convective development
tomorrow. Previous discussion follows...
Cold front remains quite evident in surface observations, with
3pm temperatures of 39 degrees in Erie, 51 degrees in Meadville
and 69 degrees in New Castle. Even so, no automated stations
were reporting precipitation in Pennsylvania, with all rain
contained to New York. The HRRR/RAP show some isolated showers
through the early evening near I 80, and have elected to just
keep slight chance pops overnight. Overnight temperatures will
be dependent on exactly how far south the front shifts
overnight, although temps should still remain well above normal
values which would range from the upper 20s to mid 30s.
Low pressure will track towards Chicago by late Sunday
afternoon, bringing an occluded front across eastern Ohio by
late afternoon. Models are still showing a bit of spread in the
arrival of precipitation, which would also impact instability
potential for thunderstorms. CAPE values appear to be rather
low, although some decent wind shear will be present. Have
included a slight chance of thunderstorms for all locations, and
half a dozen counties in our southwestern zones are under a
marginal risk for severe thunderstorms in the SPC Convective
Outlook. Another warm day is expected tomorrow, but highs will
be about 5-10 degrees cooler as a result of the thicker cloud
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.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
The occluded front will cross the region Sunday night, with the
chance of thunderstorms continuing through the evening hours.
While the bulk of the rain will move east by Monday morning,
some lingering showers will remain possible. After a brief
period of dry weather, a cold front crossing the region Tuesday
will bring another round of showers. While the precipitation
with that front doesn`t look as organized as previous model
runs, have decided to stick with likely pops for now.
Temperatures will remain above normal through the period.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
With high pressure settling in behind Tuesday`s cold front and
northerly flow developing, dry and seasonable weather is
expected Tuesday night through Thursday. By Thursday evening the
GFS and ECMWF begin to show diverging forecasts, with one model
showing low pressure over Lake Huron by Saturday morning and the
other model showing low pressure across Tennessee. Have stuck
close to the Superblend through this part of the forecast.
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
Surface winds will veer over the course of the day as a front
slowly transitions south over the region, however, VFR levels
should largely be maintained.
Widespread restrictions are likely on Sunday with crossing low
pressure, and again with a Monday night cold front.