Lancaster, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

829
FXUS61 KCTP 111739
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
139 PM EDT Wed Jun 11 2025

.SYNOPSIS...
* Trending warmer with hazy sunshine from Canadian wildfire
  smoke; most of the time will be dry through Thursday
* More humid with daily rounds of scattered rain showers and
  locally heavy thunderstorm downpours Friday through Father`s
  Day weekend

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
Hazy sunshine and rain-free conditions today with max temps
+2-8F degrees above the historical average in the 75-85F range.
Visible sat loop and HRRR smoke model show the greatest
concentration shifting to the east of the area this afternoon.
Air quality (AQI) is slightly reduced in the moderate category.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
High pressure ridge drifting off to the east tonight will create
a return flow of slightly higher dewpoints and combine with the
insulating effect of the aforementioned smoke and veil of high
clouds spreading in from the west to bring a notably milder
night with mins varying from the upper 50s (North and West high
terrain) to the low and mid 60s in the Central and Southern
Valleys.

After a mostly sunny and quite warm Thursday with temps peaking
for the week in the upper 70s (Northern Mtns) to upper 80s in
the Southern Valleys (which will be +5-10F above normal), a
quasi stationary west to east frontal zone setting up near the
PA/NY border will become a focus for episodic rain and
thunderstorms Thursday night and Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
No sig changes with this long-term update. A very wet/high-PoP
time period, for sure.

Prev...
Later this week, model consensus points to an upper trough axis
digging in along the west coast of North America, a broad and
building upper ridge over the central CONUS, and a persistent
trough axis from northeast Canada into the north Atlantic. This
leaves PA within a quasi-zonal to northwest flow pattern aloft,
with heights more elevated, at least compared to earlier in the
week.

As for the daily sensible weather, a surface cold front should
slow in its approach, as it essentially becomes parallel to the
WNW flow pattern aloft. In all likelihood, this will translate
to an increase in showers and thunderstorms, at least for the
afternoon and evening hours on Friday through the weekend.
Uncertainty increases later in the period as a trough lifts out
of the Mississippi Valley and approaches from the southwest.
There is disagreement in the guidance as to how this feature
evolves, but it will likely lead to another period of showers
and storms into the beginning of the week.

Temperatures will be within 10 degrees of seasonal normals for
mid-June, with daily highs mostly in the 70s (northern
mountains) to upper 70s-to-mid 80s (southern valleys) range.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Dewpoints not real high, but a few fair weather CU have formed
this aft. Overall main issue is some elevated smoke, but expect
conditions to remain VFR into Thursday.

Borderline for LLWS, highest chance is BFD, I did put this
in the BFD TAF tonight. Again, it is borderline.

About a 30 percent chance of a shower or storm on Thursday
across the north (spots like BFD, perhaps IPT), but highest
chance after 18Z, so left it out. Lower chance to the south
of these sites.

Outlook...

Fri...Scattered showers & storms.

Sat-Mon...Showers & storms from time to time, least
likely during the early part of each day.

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Lambert/Steinbugl/Colbert
LONG TERM...Dangelo/Colbert/Bauco
AVIATION...Martin