Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 260018

Area Forecast Discussion
National Weather Service State College PA
818 PM EDT Tue Apr 25 2017

Low pressure will track north-northeast and reach the southern
New England coast by Thursday morning. This system will bring
periods of rain through tonight followed by improving
conditions later Wednesday as the storm lifts away from the
area. A summerlike pattern is forecast later this week with
temperatures likely remaining well-above normal through the end
of April.


Mid Atlantic cutoff continues to direct moist southeast llvl
maritime flow over PA keeping low clouds...patchy drizzle and
areas of light rain over central and eastern areas late this
morning. Easterly 850 mb 40-50kt jet lifting north of the Mason
Dixon line currently supporting strong low/mid level MFLUX
surge with PW peaking around 1.50 inches...and corresponding
light to moderate rain band over the Chesapeake and nrn
MD...pushing northwestward mid to late afternoon. HRRR has been
consistent tracking this across my southern and central areas
through the late afternoon and evening hours before dissipating
over north central PA late tonight. Widespread quarter to half
inch amounts expected in these areas.

Late tonight...aforementioned anomalous jet and will move north
and east of the region...respectively. This will bring
decreasing showers to central areas...while POPs remain highest
over the east in best LLVL maritime flow. Still expect areas of
light rain and drizzle into the central mountains through 12z
Wed. Mins will drop only 3 to 6F from current readings across
central and southern areas...while the north will drop to the
upper 40s.


A very low chance for rain will linger Wednesday morning through
midday over the far eastern part of the CWA. Main story for
Wed. will be improving conditions by afternoon with increasing
sunshine (west- to- east) and the start of a significant warming
trend that should last well beyond the short term period.

Highs Wednesday afternoon should warm into the lower to middle
70s in many areas...with mid to upper 60s in the cooler eastern
valleys which will remain murky for much of the day thanks to
morning low clouds and lingering drizzle or shower spritzes.


A mild southerly flow in advance of an approaching cold front
will help boost temps +10 to +20 degrees above late April climo
by Thursday, as much of the daytime hours remain dry under
thickening clouds. Models shows the front lifting through the
area Thursday night accompanied by scattered to numerous showers
(as the parent low remains to our west and lifts across the
Great Lakes). Precip probs increase to around 60% over NW half
of CWA by Thu eve, and taper to scattered elsewhere.

Though the cold frontal boundary stalls across the region, high
pressure will keep things dry and warm on Fri. From Fri night
into Sunday things look to remain mild but become somewhat
unsettled with the medium range model guidance generating
periods of showers mainly across the NW portion of the CWA. The
placement and especially timing of these showers is difficult to
resolve at this stage with subtle waves rippling out ahead of a
system in the southern Plains - and therefore stayed close to
NBM/ECENS/WPC blend for POPS and remaining in the chance
category. While confidence is high in above normal temperatures,
the question is how warm with frontal boundaries, cloud cover
and risk for pcpn all contributing to potential bust scenario on
the high side, and latest guidance tapers temps back just a bit.

There remains a pretty strong consensus for the greatest risk
for widespread showers/tstorms on Monday May 1st associated
with a rather strong cold front and nice moisture/jet structure
crossing the Appalachians.

Temperatures will trend closer to seasonal averages behind the
front by next Tuesday May 2nd.


Low pressure lifting up the east coast will bring lowering
clouds and spotty light rain to central PA this evening. IFR
CIGs already observed at JST/AOO at 00Z and model soundings/SREF
prob charts support IFR conditions across all but IPT by late
this evening.

Early low CIGs/drizzle will give way to improving conditions
Wednesday, as the storm system weakens and passes east of the
state. Model RH profile support VFR conditions at BFD/JST by
midday, while more gradual clearing takes place across the
eastern half of the state during the afternoon.


Thu...AM fog possible. Isolated PM tsra impacts possible west.

Fri...No sig wx expected.

Sat...Rain/low CIGs possible NW Mtns. Isolated tsra impacts
possible southeast.

Sun...Low CIGs possible east. Isolated PM tsra impacts possible




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