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000
FXUS61 KCTP 240827
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
427 AM EDT Wed Apr 24 2024

.SYNOPSIS...
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-Cooler today with scattered rain showers fading into tonight
-Rain-free end to the week with frost/freeze Thu & Fri morning
-Some showers for the last weekend of April; warmer/humid Sunday
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&&

.NEAR TERM /THROUGH TONIGHT/...
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Light rain showers will move across portions of CPA this
morning in association with 500mb height fall center and
leading sfc cold front. WV/IR satellite shows a vortmax rotating
southeast from near Detroit, MI with secondary sfc cold front
moving into northwest Ohio. These features will traverse CPA
this afternoon and reinvigorate isolated to scattered rain
shower activity. A gusty low-topped t-storm remains possible as
cold temps aloft support weak instability and diurnal heating
ahead of the secondary cold front steepens low level lapse
rates. Virtually no change to the non-severe/general t-storm
outlook from SPC moving from day 3 into the day 1 period.

Highs today will trend ~5-10 degrees cooler vs. Tuesday and
ranging from the upper 40s in the NW mtns to mid 60s in the
lower Susquehanna Valley. Expect rain showers to dissipate by
tonight.

1030+mb Canadian high pressure with origins over northern
Manitoba will drift southward to a position north of Lake
Ontario overnight. Large scale downward motion and a rather
chilly and dry northerly flow should clear skies from north to
south into early Thursday morning. A freeze watch remains in
effect for active growing season zones where fcst min temps are
fcst in the 25-30F range. Dayshift can assess cloud trends and
upgrade to a warning. Frost is possible but may not be as
widespread particularly in the southern tier given persistent
north wind and lingering low cloud cover centered over the
Laurel Highlands. Frost/freeze risk outside of the watch area is
highlighted in the HWO.
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&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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Chilly/cold start Thursday followed by mostly sunny conditions
allowing temps to warm into the mid 50s to around 60F. Very dry
air/below normal pwats ~0.20 inches combined with HREF ens min
and mixed Td sounding signal suggests a floor for minRH as low
as 10-15% across the northern tier. The abnormally dry air and
favorable radiational cooling conditions will support renewed
frost/freeze concerns tomorrow night into AM Friday. This risk
is highlighted in the HWO.

The sfc high strengthens to +2SD or ~1035mb as it drifts over
interior New England to Long Island by 12Z Saturday. Rain free
wx conditions will continue through the end of the week/Friday
with sun mixing with high clouds and max temps trending warmer
into the upper 50s to lower 60s.

Showers along a warm front are likely to reach western PA by
daybreak Saturday based on latest operational model/ens
consensus. No frost/freeze concerns for Friday night into AM
Saturday with increasing clouds and fcst lows 38-45F.
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&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
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The weekend appears somewhat unsettled, with a warm front
arriving Saturday and warm sector struggling to overspread
central PA. It won`t be raining all the time, but a couple of
showers are likely on Saturday with a t-storm possible on
Sunday.

Upper ridging should eventually win out by early next week,
allowing for drier wx and much warmer temps with highs surging
through the 70s and perhaps topping 80F across the south on
Monday. A bit humid as well with fcst Td around 60F.
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&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Rain showers have moved into the western portions of the area;
however, due to very dry conditions at the surface precipitation
is struggling to reach the surface. The rain that is reaching
the ground will remain light into the morning hours. The south
to southwesterly breeze has diminished a bit, but we continue to
see occasional gusts of 15-25 kts in some locations.

Cigs will continue to gradually lower overnight, with the
western highlands (BFD, JST) dropping to MVFR, if not IFR, by
daybreak on Wed. Low probability (<20%) of LIFR exists for BFD
in the afternoon, bit cigs are more likely to remain MVFR/IFR.
The central mtns will likely drop to borderline MVFR/VFR by
daybreak, with the Lower Susq Valley remaining VFR.

We should eventually see light rain showers make it to the
ground across the western highlands, but this activity is likely
to diminish as it progresses eastward overnight. There could
also be some LLWS during the early overnight hours, with a
35-45 kt southwesterly wind a couple thousand feet above the
sfc.

Surface winds will become northwesterly overnight, and become
gusty again by Wed afternoon. Spotty showers remain possible on
throughout the day as well before completely diminishing by the
early evening.

Outlook...

Wed...Spotty -SHRA with MVFR cigs west and predominantly VFR
east.

Thu-Fri...Predominantly VFR conds under high pressure.

Fri night-Sat...Patchy rain developing from west to east.

Sun...Scattered SHRA/TSRA possible.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Freeze Watch from late tonight through Thursday morning for
PAZ004-005-010-011-017>019-025>027-045-046-049>053.

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...DeVoir/Evanego/Steinbugl
AVIATION...Evanego/Bowen