Area Forecast Discussion
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FXUS61 KPBZ 241711
Area Forecast Discussion
National Weather Service Pittsburgh PA
111 PM EDT Fri Mar 24 2017
A period of above-normal temperature and increasing chances for
rain is expected through early next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
With noon update, primary change was to increase high
temperatures this afternoon, and may not have increased
temperatures enough. Sky cover is currently less than expected,
which has allowed for greater heating. The HRRR seemed to have
the best handle on the temperature trends over the last hour or
two, and blended in the latest run. This brings the high
temperature for Pittsburgh close to 70, and this could be
conservative. Additional cloud cover will move in from the west,
but no precipitation is expected. Southwest winds will continue
to gust to 20-30 mph.
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A series of compact shortwave troughs will develop in the swrn
CONUS and eject northeastward beginning Saturday. As the first
wave acquires a negative tilt, shortwave ridging will amplify
over the Great Lakes region, leading to a likely-nwd
displacement of precipitation on Saturday and Saturday night.
Steady height falls will begin to spread across the region
Sunday morning as the ejecting wave nears. By afternoon, the
associated H5 jet maximum will cross the forecast area, likely
invigorating deeper convection with its passage amid modest
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
In the wake of the Sunday wave, a brief respite can be expected
on Monday amid shortwave ridging before a second trough ejects
from the Plains. This second wave will be favorable for
widespread rain showers as it crosses on Tuesday as warm, moist
air is drawn poleward ahead of the system.
Behind the wave, seasonable air is expected to arrive mid-week.
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Scattered mid-level cloud deck remains over the area, with
gusty southwest winds. A plume of low-level moisture, currently
over the mid-Mississippi valley will stream northeastward
tonight, eventually encountering the frontal zone set up north
of the area. This will lead to an increase in cloud cover across
our far northwest periphery, and eventually drop ceilings along
northern ports of FKL/DUJ to IFR. Just how far south this
boundary makes it remains to be seen. At this time, have the
low-level moisture staying north of PIT, but inserted several
hours of scattered MVFR for PIT/BVI for the possibility. VFR is
expected to hold through Saturday for ports south of BVI.
Wind gusts should subside with the setting sun this evening, but
an enhanced low-level jet remains over the northern portion of
the forecast area. This necessitated the inclusion of a few
hours of llws in the FKL/DUJ overnight TAF, while other
locations should remain just under the threshold. South-
southwest winds will continue into Saturday, but will generally
remain less than 10kts.
The next chance for widespread restrictions is not expected
until the approach of low pressure early on Sunday.