Area Forecast Discussion
Issued by NWS State College, PA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 180834
Area Forecast Discussion
National Weather Service State College PA
434 AM EDT Tue Oct 18 2016
Southwest flow ahead of a cold front will keep much above normal
temperatures over the region right through midweek. Cooler air will
follow the cold frontal passage Wednesday. Unsettled conditions
will redevelop for the end of the week as a series of low pressure
areas ripple up along the trailing cold front. Breezy and colder
weather will move in for the weekend.
.NEAR TERM /THROUGH TONIGHT/...
Temperatures are running some 15-25 deg warmer than normal as of
With the warm front off to our NE and the cold front still west of
Chicago, another very warm day is in store with possible record
setting warmth in several locations. See the Climo section below
for some of the records.
The cold front will be approaching the eastern Gr Lakes by
nightfall which could threaten a shower into my NWRN zones before
the day is over, but in most places it will be very warm and dry
day. HRRR suggests we should easily mix to at least 850 supporting
highs exceeding 70 over the north, and reaching at least the mid
80s over southern areas. With dewpoints nudging 60, it will even
feel a little humid.
The cold front will sag south overnight. Near term guidance is in
good agreement with the front washing and the area of showers
dwindling as it moves out of NWRN Pa down toward the coastal
plain. With the increase in cloudcover, lows will likely be even
warmer than tonight ranging from the mid 50s to mid 60s north to
.SHORT TERM /WEDNESDAY/...
Wednesday will still be very mild with almost no push of cooler
air behind the diffuse-dying cold front. A blend of models support
the potential for a stray shower over western and southern areas.
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
The trailing cold front is made to become the center of weather
attention for Thursday and Friday as a storm system or a series
of waves along the front organize over the southern Ohio Valley
and slide up through central Pa. The exact track of the low will
determine where the best rain will fall with a steady moderate to
heavy rain expected along and just behind the front, and a more
showery precipitation expected in the warm sector east of the
front. Right now the GEFS/GFS and ECMWF all show a track through
central Pa which would favor the NWRN half or so of my forecast
area for an inch or more of rain.
The upper trough will sharpen markedly as it drops through the
eastern Gr Lakes and closes off over NY before tracking into New
England and eastern Canada. A cooler blustery NW flow will develop
in its wake with scattered showers, especially over the higher
elevations of the west and north, a pattern we will see many times
over the upcoming cold weather months.
By Saturday morning it could be cold enough over the far NW for
some wet snowflakes to mix with the rain showers. Saturday night
into Sunday morning will be cooler still with a better chance of
rain or wet snow showers. No accumulations are expected.
For the last part of the weekend into early next week we should
see colder and mainly dry west/northwest flow. Deterministic GFS
differs from the ECMWF by showing a weak clipper type shortwave
bringing a chance of precip back into northern Pa by Sunday
night. The GEFS doesn`t support this. I used the blended MOS to
arrive at a very small chance of showers, but confidence is low.
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --Another morning of patchy dense fog impacting mainly portions of
the Susq River Valley, especially KIPT/KSEG/KLNS where persistent
IFR/LIFR conditions will continue until a few hours after sunrise.
Elsewhere, any restrictions will be short-lived and around
Conditions return to VFR by mid morning (poss late morning at
KIPT) as SW flow increases ahead of an approaching cold front. The
remainder of the day will be VFR with winds picking up to around
10 mph (with gusts to 14-18 mph mainly across the west).
As cold front nears this evening, showers and cig restrictions
will work into the NW mtns. As front washes out over the central
mtns heading into Wed, MVFR cig restrictions and a few stray
showers will be poss - mainly the first half of the day.
Unsettled weather will impact the area late week into the weekend.
Tonight...Reductions NW half with chance of showers.
Wed...Reductions NW half and potentially into central mtns.
Thu-Fri...Reductions likely areawide. Sct showers SE, period of
Sat...Restrictions NW. Sct showers NW. Breezy.
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Daily record maximum temperatures are in jeopardy for 10/18. Here
are the current records:
Harrisburg: 82 in 1908
Williamsport: 82 in 1964
Altoona: 81 in 1998
Bradford: 75 in 1963
State College: 83 in 1938*
*10/18 high will be officially recorded on 10/19 (7am-7am COOP)
report so used 10/19 for record purposes.
Near Term...La Corte
Short Term...La Corte
Long Term...La Corte