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000
FXUS61 KCTP 201934
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
334 PM EDT Sat Apr 20 2024

.SYNOPSIS...
An upper level trough with unseasonably cold air aloft will
swing through eastern Canada and the northeastern states late
this afternoon and Sunday, resulting in cooler and breezy
conditions.

Frost is expected in many areas of Central and Northern PA
Sunday morning, and may be even more likely on Monday morning
as high pressure moves overhead and the sky clears. Monday
night will be on the cold side still.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
*** Issued a Frost Advisory for the Central RIdge and Valley
 Region and Middle Susq Valley for 06Z-12Z Sunday after blending
 in some of the cooler NBM temps to our current fcst temps.
 Playing this early season frost on the cautious side, since
 we`ve bumped up the start of the official growing season by
 about 10 days across much of the SE half of the CWA and have
 received calls concerned about the frost. That being said, the
 negating factor for potentially more widespread frost is a
 layer of thickening Cirrus/Cirrostratus that will drift across
 much of Southern PA late tonight.

The bulk of the CWA is covered by abundant sunshine this mid
afternoon hour with SKC-SCT high-based cu.

Moderately strong low to mid level temp advection is spreading
across the region (aimed especially at the Northern Mtns -
where fairly thick stratocu and even a few showers are expected
this afternoon).

Dewpoints are mainly in the mid 20s to low 30s across the
region with temps ranging from near 50F across the NW mtns to
the low 60s in the far SE. A minor rise in temps will occur in
the SE valleys, while the NW Mtns will see temps fall back by up
to several Deg F this afternoon.

Across the Central Ridge and Valley Region, we`ll have varying
amounts of high-based cu. Deep vertical mixing up through 7-8
kft AGL will transport wind gusts of 25 to 30 kts to the surface
through 22Z before winds slacken a bit around dusk.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
After a night of lighter wind, northwest winds will increase,
but only moderately and into the teens, later Sunday morning
through the afternoon.

Another weak vort max rolls overhead in the middle of the day,
and could make a few clouds, but not likely any precip.

Will maintain just a 10 PoP for the nrn mtns for what`s likely
to be just a few sprinkles, and not actual measurable rainfall.

Temps should get back into the 50s for just about everyone
which is 5-8F below norms.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Monday looks to be dry but still colder than normal. With
light winds and dry air in place, still looking at potential
for more frost Monday night. Models show 850 mb temperatures
over Hudson Bay at times as cold as 24 degrees below at 850 mb.
Central PA nothing that cold, but did see some snow flakes at
times earlier this afternoon at JHW. I think the calender
reads late April, but mother nature making up for the all the
mild weather we had this winter and spring season so far.

Good timing between models with more showers moving into the
area around 00Z Wednesday. Showers likely to be largely out
of the area by late Wednesday evening.

While dry weather is expected Thursday into Friday, as high
pressure builds into the area, there will be potential for
frost again on Thursday night.

Temperatures will moderate by next weekend, but there will be
a chance of some showers. EC has more upper level ridging across
our area next weekend, which would support drier and warmer
conditions than the GFS would support.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
Expect VFR to prevail at all airfields through 00Z Monday,
except for some brief dips into MVFR CIGS late this afternoon
and tonight and perhaps 6SM -shra from bkn-ovc035 at KBFD.

The main concern for the rest of the daylight hours will be a
gusty WNW (270-310) wind with sustained 15-20KT speeds and
G25-33KT.

NW winds decrease tonight and conditions will be generally VFR
under an increasing/thickening layer of cirrus. Lingering
BKN025-035 CIGS could occasionally occur at KBFD and VCNTY
overnight.

Outlook...

Sun-Mon...No sig wx expected.

Tue...Slight chance of evening showers/cig reductions NW Mtns.

Wed...Showers move in west-to-east from rain early, continues
throughout the day. TSRA possible SW late PM.

Thu...Clearing as high pressure builds into the area.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 2 AM to 8 AM EDT Sunday for PAZ019-025>028-
034-035-045-046-049>053-056-057.

&&

$$

SYNOPSIS...Lambert/Dangelo
NEAR TERM...Lambert
SHORT TERM...Lambert/Dangelo
LONG TERM...Martin
AVIATION...Lambert