AFOS product AFDCTP
Dates interpreted at 00:00 UTC

Displaying AFOS PIL: AFDCTP
Product Timestamp: 2025-10-21 08:26 UTC

Download date range (UTC midnight)
Bulk Download Bulk Download
518 
FXUS61 KCTP 210826
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
426 AM EDT Tue Oct 21 2025

.SYNOPSIS...
* Mostly dry and breezy today, with some late day showers
  possible across northwest PA and the Alleghenies
* Brisk, chilly conditions Wednesday through Friday, with
  frequent showers over northwest PA, and mainly dry weather 
  otherwise
* Early indications point to a generally rain-free pattern
  Saturday and Sunday

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Early morning satellite photos show some valley fog and patchy
lower clouds in northwest PA, with generally clear skies
elsewhere. This should lead into a sunny start to the day for
most.

By midday to early afternoon, though, clouds should be on the
increase from west to east across the Commonwealth, in advance
of a progressive surface cold front. Although this system will
be moisture starved overall, the combination of upper-level
forcing in the form of height falls/DPVA and orographic
enhancement could well lead to some showers by late afternoon
across northwest PA and the Alleghenies. Model soundings and
convective indices do show the potential for a bit of
destabilization this afternoon from about the Alleghenies back
westward over western portions of the state. At this point, we
feel the best prospects for isolated thunder will be west of the
mountains. Although we may have to watch Warren county, we've
opted to leave thunder out for now.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
As an upper-level trough digs into the eastern states this
period, several waves of DPVA and steady cold air advection in
the 850-500 mb layer will lead to generally brisk and chilly
conditions for the Commonwealth. 

Increasing lake-air temperature differentials (given still 
60-65f Lake Erie water surface readings) and boundary layer 
moisture will almost certainly elicit a lake response and lead 
to bands of rain showers near and downwind from the Lake Erie 
shoreline. From Wednesday into early Thursday, projected low-
level winds from the southwest should keep the most persistent 
lake enhanced showers north and west of Warren and McKean
counties. However, Northwest PA could see an increase in lake-
effect showers by later Thursday, as low-lovel winds are 
projected to veer into the wsst-northwest. Westerly component
winds and sufficient low-level moisture should lead to 
occasional upslope showers just about anytime this period over 
and just downwind from the Allegheny plateau. 

Farther east across PA, mostly dry weather is foreseen this
period, although it will be brisk and chilly, as earlier
mentioned. If skies can sufficiently clear and winds diminish
enough Thursday night (still highly uncertain), parts of the 
Lower Susquehanna Valley that have yet to see widespread frost 
could see their first occurrence of such this season.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
From this early vantage point, consensus of our ensemble
prediction systems points to rising heights and a confluent
height pattern aloft for the northeastern CONUS, as the mid to 
late week upper trough lifts out, with lingering NW flow in the 
mid-levels. this should encourage surface ridging to build over
the region. All of this collectively indicates a drying air
mass and slowly moderating temperatures. 

There certainly is potential for some lake-effect showers to
linger over northwest PA Friday night and even into early
Saturday, but generally speaking, these showers should be on 
the decline. 

By early next week, customary uncertainty creeps in with 
regards to how quickly short-wave riding aloft over the eastern 
CONUS breaks down. However, general consensus points to dry 
weather lasting through at least Monday.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
Widespread VFR under SKC overnight into early Tuesday. Expect
wind shift to 170-240 degrees with 15-20kt gusts into Tuesday 
afternoon as a moisture-starved cold front sweeps across the 
airspace. A couple of passing rain showers may accompany the 
front and included PROB30s at the western & central terminals to
reflect the low/brief rain chances. More frequent rain showers 
and sub VFR cigs will become persistent downwind of Lake Erie 
across the western TAF sites KBFD/KJST Tuesday night through 
mid/late week. 

Outlook...

Tue-Fri...MVFR/IFR with frequent showers NW 1/2. MVFR/VFR SE 
1/2. Sfc wind gusts 20-25kt from 230-260 degrees. 

Fri night-AM Sat...Showers ending/trending VFR.

&&

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

&&

$$

SYNOPSIS...Jurewicz
NEAR TERM...Jurewicz
SHORT TERM...Jurewicz
LONG TERM...Jurewicz
AVIATION...Steinbugl/Gartner