785
FXUS61 KCTP 021919
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
319 PM EDT Tue Jul 2 2024

.SYNOPSIS...
A large high pressure system will reside overhead tonight. A
dying cold front will push in from the Great Lakes and stall
out over the area. Drier air should move in for Sunday, but
Very warm and quite humid air will returns quickly.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Sfc ridge covers all the ern CONUS. Diurnal cu should dissipate
quickly as we lose the heat of the day, and only increasing high
clouds are expected for the overnight. The wind will also be
light and from the SSE, at least on the hill tops. While the
valleys could go calm for a few hours, the threat of valley fog
in the north is lower since temps should stay much milder (near
60F for most) than Tues AM. Will not include any mentions of fog
at this point.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
Warmer air continue to invade with southerly flow increasing
slightly thru the day. Some gusts into the 15-20MPH range are
possible, mainly in the west/Alleghenies. This will help direct
higher dewpoints and PWAT values into PA. PWAT increases to 1.5"
by Wed aftn, and nears 2" for Thurs aftn. The passage of a
diffuse warm front on Wed will make for virga on the radar, and
could make a sprinkle before 5-6PM across the Alleghenies. But,
it will be after 6PM that a "real" shower (which would wet the
ground) or two gets into Warren/McKean/Elk counties. PoPs ramp
up during the evening and peak before midnight. SPC Day2 outlook
did pull the MRGL back W of the CWA. Any of the stronger storms
wouldn`t be until after dark anyway.

The cold front gets into the NW before morning, but doesn`t
have the punch/support to get through all of the CWA on
Thursday. SHRA Thurs morning will be isold. Dewpoints stay in
the 70s from I-80 southward, and only dip to the M60s in BFD.
As the front stalls, the S will still be in the warm sector
Thurs aftn. Thus, SHRA/TSRA will be likely in the S, but only
isold (20) PoPs are in order for the N with a taper through the
chc range (30-50pct) in between to account for the possible
latitude of the old front.

Since the PWATs will be high, there is the chance for a few
heavier downpours, mainly in the NW Wed night and S on Thurs.
Can`t see enough support for a FF Watch anywhere, esp with
basin avg precip from WPC being fairly paltry (0.25" even where
the certainty of rain is highest). Any storm can drop 1"/hr,
but the threat for flooding is not high at this point.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
All medium range guidance tracks a dying cold front southward
into Central PA Thursday, accompanied by a good chance of
showers/tsra. Latest RH profiles suggest there will be plenty of
cloud cover and progged mid level flow doesn`t look overly
impressive. Therefore, the severe weather threat currently looks
limited. Best guess of areal average rainfall looks to be
between 0.25 and 0.50 inches based on ensemble plumes.

The front is progged to stall out in the vicinity of Southern
PA Thursday night, then return north as a warm front Friday
ahead of low pressure lifting across the Grt Lks. Falling
heights and surging pwats ahead of an upstream shortwave and
associated surface low lifting across the Grt Lks should bring a
round of showers/tsra in the Friday PM to Saturday timeframe.
Current guidance suggests the shortwave and bulk of the large
scale forcing will pass north of PA, leading to unimpressive
mean qpf in the ensemble plumes of 0.25 to 0.50 inches Fri PM to
Saturday.

The bulk of guidance now supports fair and seasonable conditions
Sunday into at least early Monday, as surface ridging and drier
air work in behind the cold front. Showers and storms return to
the forecast for early next week as another wave of low
pressure tracking to our north brings a cold front through the
region.

Temperatures in the long term forecast look above average,
especially overnight lows Thursday and Friday night, when EPS
pwats are 150pct of normal.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
One line TAFs are almost possible for this 24hr forecast period.
Some gusts into the teens out there now due to the deep mixing
will lighten/go away before sunset. The high pressure dome
overhead will keep wind very light overnight. The Srly wind will
pick up a bit again on Wed. There is a small window of time
overnight when the wind just aloft gets up to 25-35KTs, so
we`ve mentioned LLWS in the wrn forecasts, but the core of the
faster wind is more over the NW, and we don`t expect the SErn
terminals to have LLWS. A cold front will approach Wed night and
lay out W-E over the state on Thurs. The deep moisture Wed PM
and Thurs will allow for sct-nmrs TSRA, but not until after 21Z
at BFD and much later in JST. So we`ve kept out mentions from
all TAFs from this 18Z pkg.

Outlook...

Wed night...TSRA NW (IFR poss), dry SE with no impacts.

Thu...AM low cigs and isold SHRA possible W Mtns. Sct PM TSRA
impacts possible over all the airspace, but mainly S of I-80.

Fri...sct TSRA, impacts possible, mainly PM, highest covg W.

Sat...sct-nmrs TSRA areawide, highest SE in PM.

Sun...AM fog poss. Otherwise, no sig wx.

&&

.CLIMATE...
June 2024 was the warmest June on record for Bradford with a
mean temperature of 66.6F, breaking the old record of 65.8F set
in 2021.

June 2024 was the 3rd warmest June on record for Harrisburg with
a mean temperature of 76.0F.

&&

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

&&

$$

SYNOPSIS...Dangelo
NEAR TERM...Dangelo
SHORT TERM...Dangelo
LONG TERM...Fitzgerald/Bauco
AVIATION...Dangelo
CLIMATE...Colbert