York, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

599
FXUS61 KCTP 121903
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
303 PM EDT Tue Aug 12 2025

.SYNOPSIS...
* Humid with periods of showers and locally heavy thunderstorm
  downpours Wednesday; only day of appreciable rain this week
* Dry spell returns with above normal late summer heat and
  little to no rainfall Thursday into early next week

&&

.NEAR TERM /THROUGH TONIGHT/...
Radar trends show brief pop-up thundershowers initiating on the
ridgetops before quickly dissipating as they drift off the high
terrain. Lake breeze convection has been the most persistent,
but has largely avoided the western part of Warren County. Max
POPs around 20-30% late this afternoon into early evening are
over the far NW mtns and near the highest terrain over the
central PA ridges.

Diurnal/terrain based cu will fade with the loss of heating
through the evening. Mainly clear to partly cloudy tonight with
a general increase in cloud cover into early Wednesday morning.
We added some patchy fog again overnight especially in the
central and eastern valleys with lgt/VRB wind, high dewpoints
and muggy lows in the low 60s to low 70s. Can`t rule out some
showers reaching the western periphery of the CWA by 12Z/8AM
Wednesday.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
A broad axis of above average PW values between 1.5-2 inches
(1.5 to 2+ standard deviations above the mean) will stretch
along and ahead of the primary surface front moving slowly
east/southeastward from the Lower Lakes/OH Valley region. There
is general agreement in the models for the potential for
widespread scattered convection in this high PW axis, with areal
average moderate totals depicted and likelihood of locally
heavy totals between 1 to 2+ inches based on HREF PMM/LPMM.
Confidence is low with respect to where the heavier, more
concentrated convection may be. At this time, it appears the
best locally heavy rain signal is east/southeast of the higher
terrain where models show the best CAPE/PWAT overlap. While
there will be some heavy rain rates and spot QPF amounts in the
1-2+ inch range, the recent dry spell (essentially 0.00 pcpn)
over the past 2 weeks has increased 1-3hr FFG to near max
levels. This will certainly be limiting factor concerning short
duration flash flood risk. Showers appear to linger into
Wednesday night with a decreasing trend in coverage and
intensity expected after sunset. Max/min temps in the
80-90/60-70F range will make for another hot/humid day and
muggy night.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Lingering shower activity should be confined to the southern
half of CPA on Thursday, while the northern tier begins to dry
out nicely. Lowering humidity on Friday will bring some minor
temporary relief, but overall there is no end to the run of
hot/above normal temperatures through mid August.

Another dry spell looks probable into the weekend. There is
going to be an increase in rainfall potential Sunday into early
next week as a cold front sinks southward from the Great Lakes.
Depending how far south the front can reach, some seasonably cooler
air may return by this time next week/Aug. 19-20th.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
An isolated shower or storm will be possible across the higher
terrain, given afternoon heating and dewpoints higher now.
Dewpoints higher again, then in the last 12 days. Any activity
this afternoon would weaken after sunset.

Given the higher dewpoints and rather weak wind fields, patchy
fog will be possible around or just before sunrise on Wed.

Main issue will be for bands of showers and storms, mainly
from late morning into the evening hours on Wednesday, as a
weak cold front moves into the area.

Outlook...

Thu...Lingering showers/and a few PM storms possible across the
southern airspace.

Fri...AM fog possible; otherwise VFR.

Sat...Mainly VFR.

Sun...Mainly VFR, but chance of a shower or storm north late.

Mon...Chance of a shower early, then clearing.

&&

.CLIMATE...
It`s been a very dry period over the last 2 weeks or so. Here
are the precipitation totals and rankings for the first 11 days
of August (month to date):

MDT: T (2nd driest); last measurable rain 7/31
IPT: 0.00" (driest); last measurable rain 7/30
AOO: 0.01" (2nd driest); last measurable rain 8/6
BFD: 0.09" (T5th driest); last measurable rain 8/6
STC: T (T2nd driest); last measurable rain 7/28

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl
AVIATION...Martin
CLIMATE...Steinbugl