Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 192103
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
503 PM EDT Tue Sep 19 2017

.SYNOPSIS...
A ridge of high pressure at the surface and aloft will stay
locked in place over Pennsylvania for the next 7 days. This
dominant weather feature will provide fair, warm and generally
dry weather throughout this entire period.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Though it took nearly half of the day to get started, clouds
over central PA have rapidly eroded this afternoon - with the
last patch of lower ceilings still hanging on over the Mid
Susquehanna Valley at 2pm. Temps will again peak above normal
in the upper 70s to lower 80s.

The western extent of the outer bands of showers associated
with slowly weakening Hurricane Jose look like they will just
brush our SE zones late this afternoon, and we`ll continue to
play it safe and keep mention of low pops and very low QPF (if
any) of under one-tenth of an inch.

Low level flow will become light and northerly tonight as
Jose weakens to a Tropical Storm and continues to slowly drift
off in a northeast direction. This will transition us away from
the stratus we saw this morning back to locally dense valley
fog for Wednesday morning. Min temps will be about 2-4F lower
than early Tuesday over the northern half and similar to Tuesday
for the southern half - and notably milder than normal.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
After we burn off the fog in the valleys, a spectacular
Wednesday is on tap with abundant sunshine and just a few flat
cu and thin cirrus to paint the otherwise azure blue sky. Could
be a couple of showers off to our SW in a very weak and eroding
trough, but only result for us will be potentially an increase
in cloud cover over the Laurel Highlands.

Max temps will once again range from the upper 70s across the
higher terrain of the north and west, to the lower 80s (and
maybe a few mid 80s) in the southeast.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Overall pattern hasn`t changed much, there is a good overall
consensus in the models through the second half of the work
week. For much of this period, a 590 dam closed 500 hPa high
will drift slowly out of the midwest states, and become centered
over western PA by late this weekend through early next week.

The GEFS forecasts showed this feature as a closed 5880 m ridge
over us with near +2 sigma above normal heights which will
translate to well above normal temperatures. High temps from
Wednesday and through the weekend will be 10-15F above normal
with little or no chance of rain through at least Monday.

Lows early each morning will be consistently in the mid and
upper 50s across the northern and western mtns, to lower 60s in
the larger SE metro areas.

Min temps may cool off slightly for this weekend thanks to deep
dry air and a light N to NW llvl flow of drier dewpoint air at
the sfc.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
VFR conditions the rule this evening with generally light
winds. The western extent of the outer bands of light showers
associated with slowly weakening Hurricane Jose look like they
will just brush our SE zones late this afternoon, but coverage
will remain too low to mention in LNS TAF.

Low level flow will become light and northerly tonight as
Jose weakens to a Tropical Storm and continues to slowly drift
off in a northeast direction overnight. This will transition us
away from the stratus we saw this morning back to locally dense
valley fog for Wednesday morning, which should catch many
terminals outside of the Lower Susq Valley.

.Outlook...

Wed-Sat...Patchy valley fog possible each morning. Otherwise
VFR with generally light winds and minimal clouds.

&&

.CLIMATE...
Astronomical Fall/Autumnal Equinox begins at 4:02 PM Friday
September 22, 2017.

&&

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

&&

$$
SYNOPSIS...Lambert/RXR
NEAR TERM...RXR
SHORT TERM...RXR
LONG TERM...Ceru/Gartner
AVIATION...DeVoir/RXR
CLIMATE...



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