Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 211006
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
506 AM EST Tue Feb 21 2017

.SYNOPSIS...
An extended period of mild weather with well above normal
temperatures will continue through the end of this week. A weak
cool front will push through the state late Today and Tonight
night. A stronger cold front accompanied by a few rounds of
showers is expected for Friday into Saturday, followed by a shot
of colder air with gusty westerly winds over the upcoming
weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Expect fair weather early today with increasing cirrus, as
upper level ridge axis shifts eastward from the Grt Lks. At the
surface, a dying back door cold front with shallow cool air
continues to sit over the central mountains at 0930Z (just east
of the Interstate 99 and RT 219 corridors), with markedly lower
dewpoints behind this boundary across the eastern half of the
state.

Much thinner cirrus and the drier dewpoint air has resulted in
the best radiational cooling across the eastern counties, where
min temps will dip into the mid and upper 20s. Elsewhere, temps
to start the day will be in the 30s (to near 40F across portions
of the Laurel Highlands where the thickest clouds and a 5-10kt
serly breeze will will be found).

A weakening front and the associated shearing upper shortwave
will bring increasing high clouds to the area today. This
(following the decent amount of radiational cooling we
experienced overnight) will likely result in max temps several
degrees cooler than those on Monday.

A few showers may work into the northwest mountains toward
evening, ahead of the weakening shortwave over the Grt Lks.
Otherwise, confidence is high for another dry day across the
remainder of central Pa.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
The subsiding branch of a 300 mb, 85 kt jetlet (and associated
weak sfc cool front) sags south across the commonwealth
overnight tonight. The best chc for Isolated to scattered light
showers should be prior to 08Z Wednesday.

Plenty of relatively thick mid level clouds will linger tonight,
keeping min temps well above normal and in the mid and upper 30s
(NE) to the lower-mid 40s in the southern and western portions
of the CWA.

Sunshine, mixed with varying amounts of mid and high clouds will
occur on Wednesday. Considering the mild start to the day, and
GEFS mean 850 mb temps of 7-8C, we should see max temps easily
reaching the upper 50s to lower 60s which is very close to the
latest Nat`l Blend of Models guidance.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Gradually milder temperatures will return for the extended
period as no genuine cold air push is in sight. High
temperatures in general will be 10 to 20 degrees above normal
with min temperatures mainly above freezing.

Deepening Swrly flow for the second half of the week will cause
temps to rebound to well above normal (and perhaps near record
levels in some locations).

The overall, large-scale pattern becomes more amplified late in
the week as a system over the central plains deepens and lifts
into the Great Lakes. Clouds will increase Thursday and Friday
with warm front lifting through, and bringing increasing rain
chances heading into the weekend, followed by a shot of
colder/windy conditions Saturday through Sunday.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
Predominately VFR into tonight under increasing high to mid
level clouds ahead of weakening frontal system approaching from
the Midwest. MVFR conditions are possible with light rain
showers late tonight into Wednesday morning across the NW 1/3
of the airspace.

Outlook...

Wed...A.M. sub-VFR/possible NW 1/3; otherwise VFR with light
rain showers in spots.

Thu...Sub-VFR possible with chance rain showers.

Fri...Sub-VFR possible with rain showers likely Friday night.
LLWS probable.

Sat...Strong cold FROPA with sub-VFR and possible thunderstorms.
Gusty post-frontal NW winds with snow showers NW 1/3 Saturday
night.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Lambert
LONG TERM...Lambert/Gartner
AVIATION...Steinbugl



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