850
FXUS61 KPBZ 110719
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
319 AM EDT Sat Oct 11 2025

.SYNOPSIS...
High pressure over New England continues dry and cool conditions
today. Rain chances rise late tonight and remain through the
early week especially across the eastern ridges as a weakening
Great Lakes low combines with a developing coastal storm.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:

- Slight warming trend and dry conditions today.
- Showers arrive tonight.
---------------------------------------------------------------

The Saturday morning period will feature mainly clear skies with
the exception of an approaching trough that is bringing some
cloud cover. The reason for this is an upper level closed low
from the Great Lakes slides over central PA and begins to open
up as it interacts with the closed upper low over the Southeast
that is tracking up the east coast. At the SFC, the Great Lakes
low and its associated cold front begin to drown out and
transfer energy to a budding coastal low climbing the Eastern
Seaboard. The coastal low slowly moves north and east hindered
by stubborn high pressure Sun.

Despite all of this, given the high over the New England area,
the precip is not expected to reach the forecast area until this
evening and will mainly be impacting the northern counties.
Expect widespread cloud cover with light showers through the
overnight tonight. Confidence in ample cloud cover is high but
the track of the low over the past 24 hours have shifted a bit
east. This is leading to lesser rainfall amounts. Lows tonight
will be right around average if not a degrees or 2 above given
the insulation from the cloud cover.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
KEY MESSAGES:

- Rainfall through Monday favors northern and eastern areas.
----------------------------------------------------------------

The mentioned factors in the TONIGHT period take shape for
Sunday and into Monday. The further track east will mean that
the bulk of the precip will be east of the ridges. Rain chances
peak across our eastern ridge counties Sunday and Sunday night
as energy transfers to the coastal low (30-50%). POPs in the
Pittsburgh Metro peak between 20-30% on Sunday and quickly fall
off the further west you go. At this point it looks as though
northern and eastern counties see the highest chances for
showers during this time. Rainfall totals are likely to be lower
across our area, with most of the rain falling across our
eastern counties (0.10-0.30") and then a very sharp gradient
immediately west as totals decline to a few hundredths across
the remainder of western PA. Instability is quite low but there
could be a couple of rumbles of thunder Saturday night mainly
in the far northeastern parts of the forecast area. The overall
message is a lessening trend of precip amounts and this is
confirmed by the NBM probs suggesting that the far eastern tier
of counties has a 30% to 50% probability of 0.25 inches in 48
hours.

Temperatures for highs and lows on Sunday and Monday will
feature near normal values. If anything the daytime highs are
near or 3-5 degrees above normal.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
KEY MESSAGES:

- Dry/warm weather continues into Tuesday
- Uncertainty builds mid-week with large-scale pattern
-------------------------------------------------------------------

A persistent ridge axis east of the Rocky Mountains, reaching
into the Ohio River Valley, will bring dry weather and warmer-
than-average temperatures through Tuesday.

By mid-week, it remains uncertain if a trough will form over the
Great Lakes or if the ridge will stay, and long-range ensemble
temperatures indicate about a 10-degree spread between the 25th
and 75th percentile. Should a trough pattern dominate, freezing
conditions could return, accompanied by lake-enhanced
precipitation under a northwest flow.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will continue through most of the day. Mid-level
clouds in the 6-8kft range will increase for FKL/DUJ by sunrise
as a weak cold front crosses the area, coincident with decaying
low pressure digging across the eastern Great Lakes. Mid
clouds should then spread farther southeast after sunrise.

Broad upper level ascent could result in a few scattered
showers around FKL/DUJ after 11z, but given the lower
probability and scattered nature, kept a PROB30 group. These
shouldn`t bring much in the way of restrictions with a dry sub-
cloud layer making it tough for visibility-reducing showers.
The best forcing should remain north of the remainder of the
terminals and preclude shower mention elsewhere. Light southerly
wind will veer more northerly through the morning, becoming more
northeasterly by the evening.

A coastal low tracking up the eastern seaboard will return
restrictions and potential for showers Sunday morning. There
will likely be an east-west cutoff of to the restrictions with
the highest probability lying farther east, but some uncertainty
exists with how far west sufficient moisture exists.

.OUTLOOK...
Restrictions and shower chances will likely linger through much
of Sunday and into Monday as the coastal low lifts north.
Probabilities for both ceiling restrictions and showers will
remain highest farther east with an east/west cutoff likely.
High pressure will build back into the region midweek.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

$$

SYNOPSIS...Shallenberger
NEAR TERM...Shallenberger
SHORT TERM...Shallenberger/AK
LONG TERM...Hefferan
AVIATION...Rackley/MLB