Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 201215

Area Forecast Discussion
National Weather Service State College PA
715 AM EST Mon Feb 20 2017

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. A stronger cold front is expected for Friday
into Saturday.


IR Satellite loop at 0730Z continue to show some areas of bkn-
ovc upslope stratus across portions of Cambria and Somerset
counties, mainly to the west of route 219. This area lies at the
nrn edge of a llvl Theta-E ridge, and within a 10-15kt NW wind
at 925 mb (which is orthogonal to the ridges).

Elsewhere, skies were generally clear with a light and variable
(or light nnw) wind as a sfc ridge axis slides east across the
commonwealth early this morning.

NationalBlend of Models lows, ranging from the upper 20s
northern mountains to upper 30s in the south, still appear on
track based on latest sfc observations and LAMP guidance.

Patchy low clouds will start the day across the Laurel
Highlands, and are also possible over the northern mountains.
SREF probability data strongly suggests this low level moisture
will easily mix out by late this morning, resulting in a mostly
sunny, and very mild day for the entire region.

An upper shortwave diving southeast toward New England this
evening will push another dying back door cold front into
northeast Pa during the day today. The northeast part of the
CWA will feel the greatest change, with highs potentially more
than 10F cooler than Sunday`s truly springlike feel.

However, based on recent performance of model guidance and an
expectation of mostly sunny skies, will continue to lean toward
the warmer Euro Ensemble temps, with highs ranging from the
upper 40s over the mountains north of IPT, to around 60F across
the southwest counties of the CWA.

850 mb temps do cool by about 2C from early today through this
afternoon. So, although afternoon high temps will soar to 15-20
deg above normal, they probably will stay a good 10-12 deg F
below records for today (which area: 72 at KMDT, 67 at KIPT, 62
at KAOO and 58 at KBFD).


Periods of mid and high clouds will stream SE across the region
tonight, atop a llvl ridge axis. This ridge axis will slide to
Eastern PA and Eastern New York by 12z Tuesday allowing the sfc
flow to turn to the SE, while winds up around 850 mb become
swrly at 15-20 kts.

Should increasing cloud cover ahead of an approaching weak cold
front not be as widespread or thick as currently projected,
Tuesday could easily see high temps 5-8 deg F above their
current forecast values in the low-mid 40s (NE), to the mid and
upper 50s across the SW zones.

Trimmed back timing of showers along and ahead of the
aforementioned cold front until late in the afternoon or
evening, and limited to the far NW through dusk.


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.

Upper ridge axis is forecast to be located east of the state
Tuesday night. The weak cold frontal boundary will produce a
brief period or two of showers for late Tuesday (Northwest) 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

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

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.


Predominately VFR flying expected today. Low clouds/fog
restrictions still near KJST with 1000` cig at K2G9. Also area
of stratus working south behind backdoor cold front with MVFR
cigs possible at KIPT thru 15z. Low clouds scour out giving way
to widespread VFR flying after 15z with increasing mid to high
level clouds through tonight. Surface winds 330-030 shifting to
090-150 by the end of the TAF period.


Tue...Sub-VFR possible NW 1/3 late. Chance of P.M. rain showers.

Wed...A.M. sub-VFR possible NW 1/3; otherwise VFR/no Sig Wx.

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

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


Summary of record highs from 2/18 and 2/19...

Harrisburg: Record high of 69 degrees on 2/19. Previous record
high was 66 degrees set back in 1997.

Williamsport: Record high of 69 degrees on 2/19. Previous
record high was 60 degrees set back in 1997

Altoona: Record highs of 64 degrees on 2/19 and 66 degrees on
2/18 (tie). Previous record highs were 61 in 1994 (2/19) and 66
in 1981 (2/18).

Bradford: Record high of 62 degrees on 2/18. Previous record
high was 56 degrees set back in 1994.




NEAR TERM...Lambert
SHORT TERM...Lambert
LONG TERM...Lambert/Gartner
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