Lower Paxton, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

211
FXUS61 KCTP 310318
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1118 PM EDT Sun Mar 30 2025

.SYNOPSIS...
Low pressure over Lk Huron will track north of PA early Monday,
with the trailing cold front pushing through the region Monday
afternoon and evening. Another low is likely to take a similar
track west of Pennsylvania through the Great Lakes Wednesday
night into Thursday. The front with that mid-week storm will
likely stall just to the south of Pennsylvania at the end of
next week.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
The focus overnight is on an upstream squall line entering
Eastern Ohio at 03Z. The associated potent shortwave over W
Michigan is progged to lift northeast overnight, taking the best
large scale forcing west of PA. CAMs still indicate a weakened
version of the squall line will enter the NW Mtns around 04Z-05Z.
However, given strengthening mid level flow, can`t rule out
locally strong to severe wgusts as this convection enters Warren
County.

Waning large scale forcing and a more stable air mass across
Central PA should cause convection to dwindle as it pushes into
the Alleghenies after midnight. Cloud cover, an active southerly
breeze and anomalous surface dewpoints will result in a very
warm night for late March, with lows in the mid 50s to low 60s
over most of the area.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Monday will be active, at least across the SErn third to half
of the area. A strengthening surface low will track north of PA,
dragging a trailing cold front through Central PA during the
afternoon and early evening. Latest guidance indicates the pre-
frontal low level jet and plume of deepest moisture will be over
Southeast PA. Thus, the highest POPs and best chance of severe
weather is targeted over that part of the state. RH profiles
support midday breaks in the cloud cover over the eastern half
of the forecast area, which is expected to fuel developing
afternoon convection across primarily Southeast PA based on the
latest CAMs.

Strong mid level wind/shear profiles, combined with EPS CAPES in
the 500-1000J/kg range over the Lower Susq Valley, support the
potential of severe weather Monday PM. The latest SPC Slight
Risk area extends west into the Central Mtns, but HREF updraft
helicity values target areas southeast of I-81 for the best
potential of organized severe convection. Relatively modest
instability, combined with strong forcing favoring linear
rather than discrete convection, suggests damaging wind gusts
are the main threat, with large hail/isolated tornadoes much less
likely. The threat of severe weather should end around 00Z, as
the cold front pushes southeast of the forecast area.

Ensemble mean qpf suggests rainfall Monday will range from 0.05
to 0.25 inches over most of Central PA. However, instability and
much higher PWATs southeast of KMDT should support more
substantial rainfall in that area, with heavy downpours
potentially leading to localized amounts in excess of 1.5
inches based on some HREF members. This would be beneficial
rainfall in a region that has been very dry. FFG values indicate
significant flooding is very unlikely.

Monday will be the last day of the unseasonable warmth, with
NBM guidance indicating highs ranging from around 60F over the
NW Mtns, to the mid 70s across the Susq Valley.

A much drier northwest flow will overspread the region Monday
night behind the exiting cold front, leading to breaking clouds
over most of the region. Lake effect stratocu are expected to
linger over the Alleghenies through Monday night. However,
progged inversion heights look too low to support anything more
than a few late night flurries over Warren/Mckean counties. See
no reason to deviate from NBM Monday night min temps, which
range from the upper 20s over the NW Mtns, to around 40F across
the Lower Susq Valley.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
High pressure and an associated low-PWAT airmass should build
into the region behind the exiting cold front, resulting in fair
and relatively cool weather Tuesday into early Wednesday. Guidance
then tracks another surface low west of PA through the Great
Lakes next Thursday. Rain along the attendant warm front could
spread into Central PA by Wed PM, with a chance of showers
accompanying the trailing cold front Thursday.

A cold air damming scenario ahead of the approaching warm front
with surface high east of New England supports undercutting NBM
max temps slightly Wed. However, much milder conditions are
likely Thursday, with the region potentially breaking into the
warm sector south of the surface low.

A trailing cold front is currently progged to stall out just
south of PA Thursday night. A potential wave on this boundary
looks increasingly likely to result in a period of rain Thursday
night into early Friday, especially across Southern PA. Latest
EPS/GEFS suggest a brief period of cool and drier weather is
likely Friday PM into early Saturday associated with a surface
high passing north of PA. However, another wave of low pressure
approaching from the Ohio Valley could spread rain back into the
region Saturday PM into Sunday. Latest ensemble mean qpf between
Wed PM and Sun PM is close to 2 inches over much of Central PA,
which would certainly be beneficial given the recent dryness.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Late evening update.

Most of the showers have been across the southern part of
central PA so far. One small heavier shower now northwest
of the radar.

Adjustments made to the TAFS as radar and obs support the
changes.

Earlier discussion below.

An interesting feature on radar as of 715 PM, looks like
gravity waves coming out of the area of showers southwest
of the Harrisburg area.

Not a lot of change to the 00Z TAF package. Mainly a steady
CIG for most overnight, with borderline LLWS. A few showers,
along with a chance of thunderstorm across the far west, mainly
at sites like BFD and JST late tonight.

Expect winds to pick up from the southwest on Monday, ahead
of a cold front, with a slight risk of strong to severe
storms. Timing of the front would be such at the southeast
sites like MDT and LNS have the higher chance of a gusty
storm.

Turning much cold late Monday night, along with a gusty
wind into Tuesday.

Outlook...

Tue...No significant wx or restrictions expected.

Wed...Rain moves in west-to-east late. Restrictions likely PM.

Thu...MVFR poss in widespread rain showers. TSRA poss, mainly S.
CFROPA aftn/eve.

Fri...MVFR cigs and visby expected, mainly S.

&&

.FIRE WEATHER...
Cooler and drier conditions are forecast to start April on Tuesday
as high pressure moves across PA. Dry air should support relative
humidities Tuesday afteroon falling into the 30 percent range,
and possibly lower, across most of central PA. Moderately strong
and gusty northwest winds are also possible Tuesday, but at
this time it appears the strongest winds will be in the morning.
Will continue to monitor the forecast and coordinate with BOF
and ANF for any potential need for fire weather statements and
or FWW/RFWs.

&&

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

&&

$$

SYNOPSIS...Dangelo
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Dangelo
LONG TERM...Fitzgerald
AVIATION...Martin
FIRE WEATHER...Gartner