Crucible, Pennsylvania Weather Forecast Discussion

713
FXUS61 KPBZ 200120 AAA
AFDPBZ
Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
920 PM EDT Fri Sep 19 2025
.SYNOPSIS...
Warm temperatures continue through the weekend. A front will
stall near the border of West Virginia and Pennsylvania on
Saturday, with scattered showers and storms possible southeast
of Pittsburgh. A better chance for more widespread rain arrives
next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
KEY MESSAGES:
- Dry overnight
- Patchy fog possible in a few locations
---------------------------------------------------------------
Update...
The isolated showers/storms that affected a small portion of the
area earlier today have dissipated/exited the region. The latest
surface analysis shows a weak cold front from central OH to far
southern PA. The front is expected to drift southward
overnight, with lower dew points advecting in from the north.
The 00Z PIT sounding shows some moisture between 850 mb and 675
mb, with convective temperatures in the lower 80s. This,
combined with convergence along the front, produced the showers
earlier this afternoon and evening. No additional development is
expected as temperatures continue to fall below convective
thresholds.
Previous discussion...
A mostly clear sky is expected in the evening, and then high
clouds will begin to increase late tonight, spilling over the
encroaching mid-level ridge. Low temperatures should end up
several degrees above climatology, mainly in the 50s to around
60.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
KEY MESSAGES:
- Scattered showers/storms possible mainly SE of Pittsburgh
  Saturday, otherwise dry and warm
- Still warm Sunday; isolated showers/storms NW of Pittsburgh
--------------------------------------------------------------
The boundary will likely hang around the region south of
Pittsburgh on Saturday. A weak surface low or trough is progged
to develop further west along the front, towards the Middle Ohio
Valley. This may aid the development of low-level convergent
flow, mainly in far southwest PA and northern West Virginia,
Along with the lingering moisture, this should foster better
potential for scattered showers and a thunderstorm or two.
Chances should be highest along the ridges southeast of
Pittsburgh, where localized upslope flow may aid in development.
Away from these rains, a more southerly component to flow aloft
will allow for a slow increase in mid and upper level cloud
cover. Despite this, afternoon temperatures are expected to end
up similar to Friday`s values.
The upper ridge axis departs Saturday night, and a troughing
pattern begins to develop over the Ohio Valley as shortwave
energy consolidates over the Upper Midwest. A few showers may
survive into Saturday night, as the old boundary starts to push
back north as a warm front. A temporary cloud clearing trend may
follow through the night in the warm sector. The clear sky will
not prevent a warming trend with overnight lows though, as
ongoing mixing provided by low-level southeast flow helps to
keep temperatures in the 60s for the majority of the forecast
area.
Sunday represents the start of a pattern that will hopefully at
least pump the brakes on the developing drought. The overall
trough will continue to edge eastward towards the northeast
CONUS. This will foster a generalized southwest flow providing a
better moisture feed than we have seen in some time. Ripples in
the flow may support isolated to scattered showers and storms
during the afternoon hours, mainly north and west of Pittsburgh.
These, along with the increase in clouds, may shave a couple of
degrees off of afternoon highs as compared to Saturday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
KEY MESSAGES:
- Increasing chances for beneficial rainfall early next week
- Above-normal temperatures through Wednesday, although with a
  slight downward trend
- Forecast uncertainty increases by week`s end; low rain chances
  and more seasonable temperatures are favored for now
------------------------------------------------------------------
Ensembles continue to show disagreement regarding how the trough
to our west evolves next week. Some solutions suggest that a
closed, cutoff upper low may develop somewhere over the Plains
or the Mississippi Valley, while others keep the trough more
open and baggier. Regardless, the period from Sunday night until
Tuesday/Tuesday night should contain a few chances for much-
needed rainfall across the region, given the potential parade of
shortwave troughs riding across in southwest flow. The NBM has
been showing better potential for beneficial rainfall over this
period as compared to previous runs. It suggests that 72-hour
precipitation totals ending at 12Z Wednesday have a 50 to 80
percent chance of reaching at least a half-inch across most of
the region, and a 40 to 50 percent chance of reaching an inch in
eastern Ohio. Totals could be higher locally, as convective
elements/thunderstorms appear possible on a scattered basis. At
this time, joint CAPE/shear probabilities and extended machine-
learning guidance suggest that severe weather potential appears
very low. Temperatures through Tuesday night remain above-normal
but should show a downward trend given the clouds and moisture.
Prospects for Wednesday and beyond remain murky, as much depends
on the eventual fate of the trough/upper low. The various model
clusters disagree on whether troughing remains, or whether 500mb
heights rise once again. A potential midweek frontal passage
further complicates the forecast. For now, the NBM suggestions
will be followed, with continuing but lower rain chances and a
continued slow cooling trend. Late-week high temperatures may
drop back closer to seasonal norms.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Very isolated showers linger near our southern ports as a weak cold
front drops across the region. This activity is expected to falter
shortly after sunset.
VFR with increasing surface high pressure to the NE will favor
overnight cloud clearing and shifting of the surface wind from NW to
ENE.
Models are hinting at the chance for fog development along southern
river valleys near AGC/HLG/MGW. At this time the probability is low
enough to preclude mention in the TAFs themselves. Earlier or more
stark clearing will increase this risk and a slower or patchier
clearing will lower it.
Surface convergence and lingering mid level moisture may yield an
isolated shower Saturday afternoon around/east of MGW but at this
time pops don`t look high enough to include even as a PROB30.
.OUTLOOK....
Otherwise, VFR with light easterly wind is favored until a series of
upper disturbances provide varying rain probabilities (first NW of
Pittsburgh, then areawide) Sunday through next week.  While VFR is
likely to be the predominant flight category through this timeframe,
periods of heavier rain and/or patchy morning stratocu may result in
MVFR cigs.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...CL
NEAR TERM...WM/CL
SHORT TERM...CL
LONG TERM...CL
AVIATION...Frazier/AK

NWS PBZ Office Area Forecast Discussion