Area Forecast Discussion
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FXUS61 KCTP 011558
Area Forecast Discussion
National Weather Service State College PA
1158 AM EDT Sat Oct 1 2016
A cut off upper low over the Ohio Valley will keep deep-moist
southerly flow over the region through the remainder of the
weekend. A ridge of high pressure will build east into
Pennsylvania behind this system early next week and will likely
remain over the area through the middle, and perhaps end of the
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Radar and satellite show clouds and showers feeding northward
around the upper low along the Indiana-Ohio border. This will
remain the story into Sunday before the upper low finally begins a
slow trek down the St. Lawrence River valley.
So for today we can expect a continuation of the periods of rain
and drizzle with the occasional heavier shower mixed in for good
Rainfall will average a tenth of an inch or less, however locations
seeing heavier showers could pick up 3-4 tenths of rainfall in
just a 15 to 30 minute period.
Blended model guidance (NBM) once again appears too warm and
unable to adequately handle the shallow/cool easterly low level flow
and clouds that will stay trapped in the ridge and valley region
and across the nrn mtns for much of the day. Will keep forecast
max temps nudged closer to the cooler guidance with highs this
afternoon only making it to the upper 50s across the mountains and
lower to mid 60s elsewhere.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
Skies will stay mostly cloudy to cloudy tonight (mainly in the
form of stratus) as a near sfc easterly flow persists. Isolated
to scattered showers (and some patchy drizzle along the eastern
slopes and ridge tops will occur as one disturbance aloft exits
to the northeast of the region, and another upper 90-95 kt jetlet
moves into western PA early Sunday morning.
Rainfall amounts will be generally a few hundredths of an inch at
best in most places...with around one tenth possible in a few
locations. Similar low temps are anticipated tonight - in the
lower 50s across the northern and western high terrain, and mid to
upper 50s in the central and southern valleys.
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Latest operational models track the persistent and slow-moving
cut-off low to near Detroit at 12z Sunday, before it finally
begins to turn east and gradually fills in as it gets picked up in
the longwave flow and tracks across NY state Monday.
The results on the forecast will be a continuation of showery
weather through the second half of the weekend, though with just
light amounts. Followed by a slight chance for showers across the
north early next week along with cold air advection filtering into
the region early next week.
Surface high pushing the cooler air our way slides off the New
England coast midweek, but persistent easterly flow feeding into
the Mid-Atlantic region should keep plenty of clouds around along
with at least a chance for light showers/drizzle across southern
half of CWA through midweek.
Latest on Hurricane Matthew in the 00z runs - Tremendous
differences have developed between the ominous GFS and the much
more benign forecast by the latest EC for the U.S. main-land.
The 00Z GFS brings a potent Matthew across the Western Bahamas
then has it paralleling the SE U.S. and Carolina coast late in
the week...before projecting it to get captured by a deepening
upper trough and accelerating north into Long Island next Sat/Sat
night. GEFS has roughly the same track, but as expected becomes
more diffuse through time with the location and intensity of the
storm`s center just off the East Coast.
The 30/12z operational ECMWF parked the storm over or just to the
north of the Bahamas for a prolonged period during the middle to
latter part of the upcoming week, which was a low confidence
The latest 01/00Z run of the EC now carries the hurricane well to
the northeast of the Bahamas Friday and on a steady course to the
Northeast toward Bermuda by the middle of next weekend. With such
drastic differences between the GFS/GEFS and the EC 5-7 days out,
we`ll continue to play the middle of the road and note just
scattered showers with the passage of a more definitive northern
stream shortwave and sfc cold front late next week or early next
Temperatures will be slightly below normal through the latter half
of the weekend, before shifting to slightly above normal by the
middle of next week...then possibly dipping back to near normal as
clouds (at least the mid and high variety) thicken-up to the NW of
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
Widespread IFR conditions will continue into tonight with periods
of rain, drizzle and fog. Gradual improvement to MVFR/VFR is
projected by later Sunday into next week as the upper low finally
begins to pull away from the region.
Sun...IFR trending to MVFR/VFR late. Scattered showers continuing.
Mon-Tue...Gradual improvement likely.
NEAR TERM...La Corte/Lambert