Area Forecast Discussion
Issued by NWS State College, PA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 212000
Area Forecast Discussion
National Weather Service State College PA
400 PM EDT SUN AUG 21 2016
A cold front will push through the region late this afternoon,
followed by a cooler airmass with much lower humidity. It will be
very comfortable for much of the upcoming week. The next
significant chance for rain won`t arrive late Thursday or Friday
as a rather weak cold front slides southeast across the state.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Plume of tropical moisture (with PWATs over 2 inches), a belt of
mdtly strong llvl southerly winds, and approaching height falls
combined to create widespread moderate to heavy showers (that
brought much of the region between 0.75-1.5 inches of rain since
this morning) ahead of a cold front.
The bulk of the rain showers will exit quickly east of the region
over the next few hours, followed by a few hour period of rising
ceiling height with just some stray light showers along and just
ahead of the cold front (and within a region of broad, large
scale via the RE of a 95 kt swrly upper jet).
For this evening and much of the overnight across the Susq Valley
and central mtns...partly cloudy, dry, and comfortably cooler air
will advect in with PWATs dripping to around 0.75 inch my 12z
Monday. Min temps will be in the u50s to l60s.
Upper trough and associated cooler 850-500mb temps will bring
a bkn-ovc dual layer of strato cu and altocu late tonight, with a
few light showers possible at KJST and KBFD. Pops will only be in
the 20-30 percent range, and QPF will be under 0.10 (more likely
just some spotty amts in the 0.01-0.03 of an inch range).
Min temps across the nrn and western mtns will be in the l-m50s.
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
Monday will seem like we`ve jumped right into a splendid very late
summer/early Autumn day with refreshingly cooler temps (especially
across the mtns) and low humidity.
Max temps (in the u60s to l70s across the mtns, and u70s to around
80F in the Susq Valley) will be 3-9 deg F below normal for the
NW winds averaging 8-10 kts will gust into the mid to upper teens
(kts) at times during the late morning/afternoon.
Bkn clouds with possibly a few sprinkles will persist across the
mtns until around 16Z...with mainly sunny skies in all areas for
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --Cooler, drier air will advect into the region bringing a long
period of precipitation-free weather through most of next week.
The next period of active weather will come as an upper level
trough moves into the region Thursday night into Friday. A front
with +1 to 2 STD/anomalous PWATS progress through Friday. That
should correspond with a passing but possibly weakening/shearing
cold front. Dry air under high pressure is expected for next
The week will start off cooler due to the northwesterly flow but
will gradually warm as the week continues with temperatures
slightly above normal through the second half of the week. What
will also make this week feel cooler is the lack of humidity as
dewpoints will be in the 50s through most of the week.
-- End Changed Discussion --
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
Aside from some (departing) MVFR cigs and vsbys across the
extreme east for the next hour...widespread VFR will be
accompanied significantly drier air with excellent vsby being
transported east by a 10-15 kt west - wnw breeze in the wake of a
cold frontal passage late this afternoon and early this evening.
Cool pool of air aloft will bring some mvfr clouds back to the NW
Mtns and Laurel Highlands late tonight and they will persist
through 16Z Monday. Elsewhere...expect widespread MVFR.
NW-NNW sfc winds Monday could ocnly gust into the 15-18 mph range
in the 15-22z period.
clear skies and diminishing wind will allow for strong radiational
cooling of the ground Monday night with the air/stream-river-lake
temp difference exceeding 20 deg F. This will bring
patchy...locally dense valley fog 09z-13z Tuesday.
Mon...Areas of morning MVFR cogs possible across the Allegheny
Mtns of northern and western PA...otherwise VFR.
Tue-Wed...Patchy AM fog possible.
Thu...Isold pm tsra impacts possible w mtns.
The KCCX radar was activated in order to monitor the active
weather earlier today. Radome painting is not yet complete.
Therefore, the radar will likely be taken off line during the
benign weather stretch in the first part of this week to allow the
work to be completed.