NWS Forecast Discussion
038
FXUS61 KCTP 301122
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
622 AM EST Mon Dec 30 2024
.SYNOPSIS...
* Blustery conditions will continue today with frequent rain and
snow showers across northwest PA today.
* A ridge of high pressure brings dry conditions tonight into
Tuesday morning followed by another round of rain later
Tuesday afternoon into early Wednesday.
* Gusty winds and a colder airmass arrives on Wednesday and
continues through the end of the week as lake effect snow
ramps up to kick of 2025.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Surface cold front was marching east across the Susquehanna
River Valley early today followed by gusty west-southwest winds
and several bands of light showers moving east of the
Interstate 99/Route 220 Corridor.
More widespread rain showers within a potent mid and upper level
trough will drift into NW PA for the mid to late morning hours
and gradually transition to mainly snow showers over the higher
Terrain INVOF KBFD with a ground whitening possible.
Wind gusts of 35 to 40 mph will occur this morning as the LLVL
P-gradient tightens quickly. Lower wind gusts by 5-10 mph will
occur in the wake of the aforementioned Cfront across the SE
half of the CWA.
High temps across the Western Mtns in the upper 30s to mid 40s will
occur early today before leveling off or even sliding by a few
degrees this afternoon. The Central Ridge and Valley Region and
Susq Valley will see just a slight rise in temps in the
downslope westerly flow behind the cold front before the cold
air deepens later today.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A ridge of high pressure at the sfc and aloft will slide east
across the region tonight with a brief period of clear to partly
cloudy skies early, followed by thickening high clouds late.
Mins tonight will be in a rather tight range (in the upper 20s
to mid 30s) as the cloud cover cuts off radiational cooling
first and most across the typically colder NW Mtns and Laurels -
leveling the playing field for temps.
By Tuesday afternoon, precipitation ahead of our next weather
maker will move into southwest PA. Rain will overspread the
region during the day on Tuesday as an occluded front crosses
the state attached to a center of low pressure that will move
across northwest PA Tuesday night into Wednesday morning. A
trailing cold front will be followed closely be a reinforcing
shot of cold air by Wednesday morning, which will promote a
transition to rain/snow during the pre- dawn and morning hours
on Wednesday. At this time, there remains some uncertainty with
regards to the southern extent of precipitation, as a more
northerly track could allow for a drier solution for the Lower
Susquehanna Valley while a southerly track would promote higher
PoPs on Wednesday.
Winds will shift to the west/northwest Wednesday and Wednesday
night and increase considerably behind the departing cold
front(s) and surface low. Have trended above NBM guidance for
winds and wind gusts on Wednesday & Wednesday night to account
for the synoptically- enhanced pattern. Meanwhile, subzero C
850mb temps traversing the Lake Erie waters will also
reinvigorate the lake effect snow machine by Thursday morning,
which a preferred fetch into northwest PA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Zonal flow aloft continues Thursday and Friday with a deep low
pressure center parked over the Canadian Maritimes and high
pressure over central Canada. The result with be a persistent
northwest flow with cold air funneling into much of the lower
48. Pennsylvania looks likely to be in gradient flow for the
end of the week and into the weekend. The result will be
blustery winds, lake effect snow, and a downward trend in
temperatures each day to kick of 2025.
Highs on Thursday are progged to be in the middle 20s to near
40. By the end of the weekend, highs may be 10 or more degrees
colder, with lows in the upper teens to near 30. Add in some
winds, and single digit wind chills are likely for through the
extended period. On the heels of 2024, which is likely to be
the warmest year on record across much of Pennsylvania, 2025 is
expected to start off will a prolonged stretch of below- normal
temperatures.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
At 12z, scattered rain showers continue across the western
highlands (BFD/JST) along with MVFR cigs. Generally VFR conds
were found elsewhere. A westerly breeze is occasionally gusting
20+ kts.
The breeze will continue to occasionally gust over 20 kts today.
There is an ~80% probability that cigs will dip to IFR at BFD
today with scattered showers continuing, and MVFR cigs are
likely to persist at JST. Borderline MVFR/VFR cigs are expected
across the central mtns (AOO/UNV/IPT), with VFR conds persisting
across the Lower Susq Valley (MDT/LNS).
Winds and lingering clouds will diminish early tonight, before
clouds thicken again later tonight into Tuesday. Another round
of rain will gradually overspread the area from west to east on
Tuesday as the day progresses.
Outlook...
Tue...Increasing clouds with rain and restrictions developing.
Wed...Rain pulls east of the area, with gusty west winds
developing. -SHSN developing N/W PA.
Thu-Fri...Restrictions remain poss N/W in -SHSN; gusty west
winds continue areawide.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert/Banghoff
NEAR TERM...Lambert/Banghoff
SHORT TERM...Lambert/Banghoff
LONG TERM...Banghoff
AVIATION...Evanego
NWS CTP Office Area Forecast Discussion
