397
FXUS61 KCTP 121712
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
112 PM EDT Wed Mar 12 2025

.SYNOPSIS...
* After a brief cool down on Wednesday, warmer temperatures will
  return late in the week and remain with us into the weekend.
* A strong low pressure system will bring gusty winds this
  weekend and a threat for severe weather on Sunday.
* Temperatures trend briefly cooler for St. Patrick`s Day before
  moderating again next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Temperatures today will be about 10-25 degrees colder than
Tuesday`s highs, as high pressure builds to the north of the
state. Winds will be light as they gradually veer from NE early
to E and then SE through the afternoon. Highs today will range
from the mid 40s in the northeast to near 60 degrees across the
southern tier. Lighter winds should limit the risk of wildfire
spread somewhat, but low relative humidity (20 to 35 pct) is
expected once again this afternoon.

Warm advection will ramp up late today ahead of a shortwave
crossing the Great Lakes. As a result, expect thickening clouds
over Northern PA, where a few light rain showers are possible
in the afternoon and evening. Model soundings indicate some wet
snowflakes could mix in along the NY border, but accumulation is
not expected. The shortwave should have passed north of the
region by late tonight night, ending the chance of
precipitation. Meanwhile, clouds will begin to advect in from
the Chesapeake Bay across central and southeast PA tonight and
overcast skies are expected across most of the area by
daybreak. Lows will range from the low 30s in northeast PA to
low 40s in the Laurel Highlands.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
Low amplitude upper level ridging should keep Central PA
weather dry Thursday and Friday, though some light rain is
possible in the Laurel Highlands Thursday afternoon as an
inverted trough on the north end of an open wave moves across
the region. Low level easterly flow associated with high
pressure east of New England should keep daytime temps a bit
cooler than NBM guidance and a trend toward more clouds to end
the week.

Latest expectation is that clouds will overspread PA during the
pre-dawn hours Thursday and Friday morning, overstay their
welcome for much of the day both Thursday and Friday, and then
retreat some each afternoon/evening. Temperatures in the 50s
are currently on the cooler end of the ensemble spread, but this
still corresponds to temperatures +5 to 15 compared to average
for this time of year.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A complex system is expected to impact central Pennsylvania
this weekend as low pressure moves across the central US into
the Great Lake region. Rain showers remain possible, mainly
across western Pennsylvania, on Saturday given westerly flow and
an initial slug of moisture. Model guidance has been persistent
that the best chances of precipitation will occur on Sunday;
however, timing compared to yesterday has trended slightly later
into the afternoon hours. The abundance of moisture, collocated
with the best forcing brings high confidence in rain
overspreading much of the area by the late morning/early
afternoon hours. Enhanced southerly flow will also bring a
second slug of moisture from the Chesapeake Bay to portions of
eastern Pennsylvania during the afternoon hours, allowing for
increased precipitation with PWAT values in recent guidance
lighting up towards the 1.00-1.50" range across the eastern half
of the area. Comparing model PWAT values to previous soundings
for IAD and PIT outline that PWAT values will approach maximum
values for March 16th ~12Z, if model guidance continues to hold.
This rainfall will be largely beneficial over long- term
drought areas of eastern Pennsylvania with no large- scale
flooding concerns at this time.

The slightly later arrival of the cold front will also
introduce severe potential across southeastern Pennsylvania,
where the aforementioned moist airmass, coupled with ample
forcing and strong deep-layer flow will provide some potential
for damaging winds across southeastern Pennsylvania. Given
timing of the cold frontal passage, this threat is mainly
confined to the Lower Susquehanna Valley as outlined on the
Storm Prediction Center`s D6 Severe Outlook.

Another facet of this complex system will be the non-
thunderstorm wind, with the threat for strong southerly winds
maximized on Sunday. A fairly tight pressure gradient sets up
across western Pennsylvania late Saturday, with enhanced winds
on the ridgetops of western Pennsylvania. Recent model guidance
has trended downward with wind gusts/strength of the gradient;
however, there remains slight model inconsistencies within this
Saturday-Sunday morning timeframe. Enhancement of wind gusts
appear more likely on Sunday, where enhancement of the 925mb
low-level jet ramps up across eastern Pennsylvania, bringing an
increased potential for strong winds. At this time, point-based
forecasts exceed Wind Advisory criteria; however, still quite a
bit of time to tighten up the wind forecast on Sunday before
headlines will need to be considered.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR conditions prevail today as a cold front moves south of the
area. Clear skies exist across all airfields except BFD and IPT
this afternoon and that should remain true until after 06Z.

There is a low (20-30 percent) chance of a rain shower this
evening at BFD, though this chance appears to be decreasing with
time. No restrictions are expected in any rain.

By tonight, southeast flow will advect low clouds into central
and southeast PA after midnight and those clouds will hold on at
least through mid morning on Thursday. A period of MVFR
restrictions appears most likely bas early as 09Z at MDT and LNS
extending to UNV/IPT/AOO by 12Z and then gradually improving
through 18Z. IFR is possible at UNV/MDT/LNS, with the highest
probability occurring between 12Z and 15Z.

Outlook...

Thu...MVFR cigs gradually improve; isold SHRA possible mainly
wrn PA.

Fri...Restrictions in low clouds/southeast flow.

Sat...SHRA, highest chances across W PA, restrictions possible.

Sun...Widespread SHRA, TSRA possible across SE PA. Restrictions
probable.

&&

.CLIMATE...
A record high temperature of 75 degrees was set at Williamsport PA
on Tuesday. This broke the old record of 71 degrees set in 1977.

Bradford tied their record temperature of 66 degrees on Tuesday.
The previous record high was also set in 1977.

Altoona tied their record temperature of 74 degrees on Tuesday.
The previous record high was also set back in 1977.

&&

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

&&

$$

SYNOPSIS...Banghoff/Colbert
NEAR TERM...Banghoff
SHORT TERM...Fitzgerald/Banghoff/Colbert
LONG TERM...Colbert/NPB
AVIATION...Martin
CLIMATE...Martin/Bowen