836
FXUS61 KCTP 060927
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
527 AM EDT Sun Jul 6 2025

.SYNOPSIS...
* Our current warming trend peaks today and Monday afternoon
  before a weak cold front slides slowly southeast across the
  region late Monday and Tuesday and eventually stalls out for
  a few days across Southern PA or Northern VA.

* Daily chances for showers and t-storms will occur through much
  of the upcoming week thanks to the slow moving frontal
  boundary and several weak waves of low pressure moving east
  along it, including the moisture from the expected remnants
  of Chantal.

&&

.NEAR TERM /THROUGH TONIGHT/...
Fair and quite mild conditions for a summer night with variable
amounts of cirrus spilling south and west across the CWA as
high pressure at 300 mb is centered nearly overhead.

Temps will start the day in the low-mid 60s over the higher
terrain of northern and western PA and in the upper 60s to
around 70s throughout the Susq River Valley.

Today will be just a few degrees warmer compared to Saturday,
and still looks rain free for now. Central PA will be in the
squeeze play subsidence zone between approaching cold front to
the west and TS Chantal near the Carolina coast.

Beneath the axis of the upper level ridge shifting east across
the Commonwealth today, mid level temps will warm to around
+10C, likely preventing any convection, except for perhaps one
or 2 isolated cells over the ridgetops and near the SE boundary
of the Lake Erie Breeze.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
PoPs increase into Monday as a relatively weak northern stream
upper level trough arrives and taps into some tropical moisture
off the East Coast. With more moisture in place, heat index
values Monday afternoon will climb into the 90s for most valley
locations south of the northern tier. It will also be quite
muggy overnight with lows in the mid 60s to low 70s (NW to SE)
Monday night.

SPC has the NW 20-25 percent of the CWA in a MRGL risk for SVR
Monday, along with a MRGL risk for excessive rain. These
categories look reasonable at this point based on instability
(MU CAPE nearing 2000 J/KG across the NW Mtns), deep layer shear
and PWAT values of 1.75+ inches across the NW Mtns (and
slightly over 2 inches across the far SE thanks to moisture from
the remnants of TS Chantal brushing that part of the state.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Temps will fall a few degrees into Tue as showers and storms
stick around. The aforementioned cold front will likely push
through the Central and Southeast counties of the CWA during
the day Tuesday. SPC has the SE 40 percent of the CWA in a MRGL
risk for SVR Tuesday, along with a MRGL risk for excessive rain

PoPs drop into the 20-40 pct range on Wed as heights briefly
rise over the area, but most model guidance still shows enough
instability for at least a few isolated showers and storms,
especially across the southern part of the CWA where SFC based
CAPE still peaks between 1500-2500 J/KG WED and Thu afternoon.

PoPs rise again Thursday with the approach of another shortwave
trough. The forecast for Friday and the weekend is more
uncertain, with some guidance suggesting a break in the
unsettled pattern, and others suggesting active weather
continues.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
Still some high level clouds and a few Cu early this evening.
With fading heating, expect any lower clouds to crumble with dry
and VFR conds overnight. Highest chc of a shower or storm
remains vicinity of BFD for another hour or two, but no higher
than a 20 percent chance.

The airmass still rather dry for early July, so not much
chc of fog tonight.

Sunday a bit more in the higher dewpoints, but the chc
of a shower or storm look to still be very low.

Main chc for any showers and storms will be from late Monday
into Thursday as dewpoints increase and weak systems act on the
moisture.

Outlook...

Sun...VFR.

Mon-Thu...Potential for showers and thunderstorms, mainly
aftn/eve.

&&

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

&&

$$

SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Lambert
LONG TERM...Lambert/Colbert
AVIATION...Martin/Gartner