Area Forecast Discussion
Issued by NWS State College, PA

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322
FXUS61 KCTP 191033
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
533 AM EST Sun Feb 19 2017

.SYNOPSIS...
An extended period of mild, spring-like weather with well above
normal temperatures is expected through the end of the upcoming
week. A weak cool front will push through the state late Tuesday
and Tuesday night, accompanied by a few periods of mainly light
showers. A better chance for showers will come Friday into
Saturday as a strong cold front pushes east from the Ohio
Valley.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The northern edge of higher PWAT air around 0.75 of an inch will
slide across the southern tier counties of PA through the mid
morning hours. the northern edge of a stratus/stratocu deck
based between 1000-1500 ft AGL will coincide with this northern
limit of higher PWAT air, and will be topped by some altocu and
cirrus. Across central and northern part of the CWA mainly clear
skies at 0930Z will be followed by periods of cirrus clouds as a
shortwave aloft moves from the glakes region to southern New
England today, and pushes a backdoor cold front into central and
NERN PA late today and tonight. 850 mb temps cool by as much as
7C over the far NE corner of the state, and 3-4C elsewhere along
and to the east of the RT 322 corridor.

Temps to start the day today will range from the upper 30s to
lower 40s across much of northern PA, to the mid 50s across the
far SE where the most and thickest cloud cover will prevail.

GEFS mean 850mb temps will be about 2-4C cooler than Saturday,
which will lead to maxes from around 50F over the northern
tier, to the low and mid 60s in the southern valleys.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
The backdoor cold front (and shallow cold air to its east)
should back wwd and bank up against the Allegheny Front late
tonight and Monday. Shallow stratus are likely across roughly
the NE half of PA early Monday, but should mix out in most
places by late Monday morning as the cooler air will be very
shallow and lack a significant easterly upslope component.

A mostly sunny late morning and afternoon Monday will combine
with 850 mb temps of 1-3C across much of the region to yield max
temps in the lower 50s. Readings will reach the mid 50s over the
SW part of our CWA, but only make it to around 40F across the
highest terrain of Sullivan County in the far NW where 850 mb
temps will stay around 0C for much of the day.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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.

The rather strong sfc ridge slides to the Mid Atlantic/Southern
New England Coast on Tuesday, followed by a weak cold frontal
boundary and a brief period or two of showers for late Tuesday
(West) and over the Central and Eastern parts of PA Tuesday
night into the mid morning hours of Wednesday.

Clouds associated with this weak frontal boundary will help to
suppress temps a bit (but they`ll still remain well above
average).

The flow turns back to the SW by Wednesday causing temps to
rebound.

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.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
19/09z update: Risk for sub-VFR cigs at JST/AOO has increased
based on IR satellite trends and nearby observations. JST most
likely to see period of IFR cigs. Added SCT010-025 group for
now will amend as necessary.

19/06z: Guidance trend has been too bullish for sub-VFR cigs
over the western 1/2 of the airspace, with dry air/large T-Td
spreads keeping cigs AOA 10kft. Therefore 06/19z TAFs are more
optimistic with prevailing VFR through the period. MVFR cigs and
-RA near KMGW/K264 should remain south of PA/MD border, but did
include BKN050 group at JST to reflect some lowering of clouds
toward daybreak. Surface wind gusts up to 20kts from 250-280
degrees from mid morning through the afternoon. Backdoor cold
front may bring some lower cigs into the northeast 1/2 of the
airspace after midnight into early Monday morning.

Outlook...

Mon...VFR/No sig wx.

Tue-Thu...Sub-VFR psbl with chance of rain showers.

&&

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

&&

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



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