Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
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FXUS61 KCTP 241920
Area Forecast Discussion
National Weather Service State College PA
320 PM EDT Mon Oct 24 2016
Northwesterly winds will continue tonight and Tuesday, occasionally
producing light showers over the mountains. High pressure overhead on
Wednesday morning will allow temperatures to near or drop below
freezing over most of Central PA.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Mins tonight will be controlled by the cloud cover. Trouble is,
that is a tough forecast. RH remains high in the LLVLs, but
downsloping and some mixing due to still-strong gradient flow will
duke it out for how much cloudiness exists overnight and where.
Will keep the forecast very climo with mostly cloudy to the NW of
IPT-UNV-AOO. Current partly-cloudiness should fill in with some
stabilization this evening. Will go for mins close to freezing on
the highest elevations, but m30s-m40s elsewhere. Of course, some
showers will run off the lakes all night, and some may be a mix
instead of plain rain. Snow accums are not expected due to warm
ground and --precip.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Tuesday looks very much like Monday just a few degs colder. The
wind should start to slacken later in the day but may not go calm
Temps again the trouble for Tues PM/Wed AM. In this case, the
5-10F temp drop from Mon PM to Tues PM will spell a moderate-high
threat for freezing temps across the whole CWA, and could kill off
the rest of the vegetation across the SE, ending the growing
season. Have posted a freeze watch for that possibility.
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Surface high pressure gradually works in from the Great Lakes Tue
into Wed keeping below normal temperatures in place. Cyclonic
flow/cold air aloft on Tue may bring enough instability to kick
off a few light showers in the NW mountains.
CAA comes to an end on Wed as weak progressive upper ridge
moves through as low-level flow turns back to the S/SW. Could see
a decent frost Wed morning as dewpoints bottom out.
A compact low developing over the Midwest will already be
knocking on our door by Thu. Drier air remains in place over the
east Wed night, but expect showers to work into the west
overnight. Rain becomes likely for much of the area on Thu.
Model guidance continues to diverge after that, especially at the
surface, so confidence in next weekends forecast remains rather
low. But a look at the upper pattern suggests general NW flow
keeping a steady stream of cooler air feeding into the region,
with a series of shortwave troughs sliding through.
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
Moisture flowing off of Lk Erie will continue to produce fairly
widespread stratocu across Central PA into Tuesday. Current VFR
CIGs will likely dip a bit and end up MVFR over the mountains. VFR
still expected in the SE, and it may even clear out for that area.
Winds will stay up about 7-10KT for most of the terminals, but it
won`t be quite as gusty as nighttime stabilization happens.
Tuesday should be similar to Monday as the flow changes little in
direction but does get a little lighter.
Wed...Patchy AM fog. Freezing temps. Otherwise, no sig wx.
Thu...Rain/low cig possible.
Fri-Sat...MVFR/sct -shra N/W. VFR elsewhere.
Freeze Watch from late Tuesday night through Wednesday morning