Bairdford Pennsylvania Weather Forecast Discussion

099
FXUS61 KPBZ 141639
AFDPBZ
Area Forecast Discussion
National Weather Service Pittsburgh PA
1239 PM EDT Tue Oct 14 2025
.SYNOPSIS...
Dry and seasonably warm conditions are expected today before a
dry cold front passes Wednesday morning. The cooler air mass
may create frost and localized freeze conditions Thursday and
Friday mornings. Rain may return for portions of the region
Saturday before more widespread rain develops with a cold front
Sunday.
&&
.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Seasonable to slightly above average temperature this
  afternoon with eroding stratus
- A dry cold front is expected to cross overnight and increase
  cloud cover.
---------------------------------------------------------------
Subsidence from upper ridging will continue to aid in the
erosion of a staunch stratus layer through this evening.
Increased insolation will aid early cloud-clearing locations to
reach high temperature around 5 degrees above the daily average
while locations seeing a later onset of sunshine trending closer
to near (or slightly below) the daily average. Diurnally-driven
cumulus behind the eroding cloud deck is expected to clear
around sunset.
A cold front draped across south central MI towards Toronto
(Canada) is expected to drop SSE through the overnight period.
Limited moisture within the atmospheric column and meager lift
should ensure dry conditions but cold advection should allow the
increase in stratocumulus development in the post-frontal
environment. This cloud cover and later arrival of cooler air
means overnight low temperature remains near to slightly above
the daily average.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
KEY MESSAGES:
- High confidence in dry conditions
- Frost/freeze conditions appear increasingly likely Wednesday night
and Thursday night
----------------------------------------------------------------
There is high confidence in dry conditions persisting Wednesday and
Thursday as the local area remains under an area of northwest flow,
sandwiched between a broad upper ridge over the central CONUS and a
deepening longwave trough over the western Atlantic. Cooler air will
filter into the area in response to the amplifying pattern, with
high temperatures each afternoon returning to near seasonal levels
(low 60s for the Pittsburgh area). As the surface high shifts
eastward and centers more over the lower Great Lakes, we will see
drier air and calming winds which should result in very efficient
nighttime radiational cooling.
A frost/freeze remains possible both Wednesday and Thursday nights.
The most likely areas to experience frost will be north and east of
Pittsburgh, where NBM probabilities are near 100 percent for low
temperatures dropping to 36F or lower (a decent proxy for frost
formation in situations like this). Elsewhere across eastern OH,
northern WV, and southwestern PA, locations outside of the immediate
Ohio River valley generally see frost probabilities ranging from 40
to 60 percent. With respect to freeze conditions, NBM probabilities
for low temperatures at or below 32F are as much as 60-90% for areas
north and east of Pittsburgh and the Laurel Highlands. Therefore,
expect some combination of frost/freeze headlines Wednesday night.
There are higher probabilities for frost/freeze conditions across a
larger portion of the area Thursday night, but any headlines for
that period will be dictated by the expanse and magnitude of
frost/freeze conditions Wednesday night, as the growing season may
end for many locations on Thursday.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
KEY MESSAGES:
- Above average temperatures return Friday into the weekend
- Rain chances increasing late this weekend
-------------------------------------------------------------------
The central CONUS ridge shifts eastward Friday through the weekend,
centering over the local area early Saturday and over the eastern
seaboard on Sunday as an upstream trough deepens over the upper
Midwest and Great Lakes. Mostly dry conditions can be expected to
start the period, though guidance does suggest a low chance for
decaying rain showers to make their way across mainly the northern
half of the area Friday night into early Saturday morning. However,
confidence in this occuring remains low as ensembles are currently
in a rather significant disagreement regarding the magnitude of dry
air below 700mb and thus the amount of sub-cloud evaporation. The
current NBM mean maintains low (20-30%) PoPs north of I-70 which
seems reasonable at this time given the uncertainty. Regardless, if
precipitation occurs it would be very light, with even the LREF 90th
percentile topping out at only a tenth of an inch of total rainfall
during that period (and primarily focused north of Pittsburgh).
As the central CONUS trough continues to advance eastward, it pushes
the upper ridge out over the western Atlantic, returning the local
area to unsettled weather and increasing chances for showers and
thunderstorms Saturday night through Sunday night. Current ensemble
guidance indicates 24-hour totals generally ranging from 0.25" to
0.75" across the region within the 25th to 75th percentile range.
However, there continues to be some outlying members that indicate a
non-zero chance for higher amounts approaching 1.0 to 1.25 inches in
some locations.
Temperatures trend warmer Friday through Sunday, climbing back above
seasonal normals with the warmest day looking to be Saturday as
highs climb into the low to mid 70s. A cold front on Sunday brings
temperatures back down to near seasonal levels to start next week.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Northwest to southeast erosion of the MVFR stratus will continue
through this evening due to subsidence aloft. Scattered to
briefly broken low VFR/high MVFR remains possible behind the
eroding stratus in conjunction with diurnal heating, but
duration of broken cig conditions are likely to be short-lived.
Confidence is high all terminals will return to VFR by 00z, with
occasionally gusty NNE wind (15-20kts during the afternoon)
subsiding.
A dry cold front will drop SSE through the region between
05z-14z Wednesday, with impacts mainly tied to the spread of cig
restrictions. Model guidance remains varied on the coverage of
any post-frontal cloud deck (formed via cold advection and weak
moisture influx from Lake Erie) as well as exact heights. Given
prior stratus struggles of broader model consensus, TAFs are
trended towards HREF probabilities that suggest 50-90% of at
least MVFR cigs (with highest confidence at KMGW due to moisture
convergence/upslope flow with higher terrain); probabilities
remain elevated for stratus to be IFR or lower but confidence
is not high enough at the moment given 12z model data is still
finalizing.
Dry advection and subsidence will erode any MVFR stratus by
Wednesday afternoon (80-90% confidence of VFR by 18z). There is
potential for a stray sprinkle/drizzle due to warm advection
aloft but a dry mid-level layer creates a too low probability of
it reaching the ground.
.OUTLOOK...
Surface high pressure with height rises aloft favor VFR into
Saturday morning before a series of shortwaves ahead of the next
cold front bring increased rain and restriction chances.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Frazier
NEAR TERM...Frazier
SHORT TERM...Cermak
LONG TERM...Cermak
AVIATION...Frazier

NWS PBZ Office Area Forecast Discussion