Confluence, Pennsylvania Weather Forecast Discussion

433
FXUS61 KPBZ 271739
AFDPBZ
Area Forecast Discussion
National Weather Service Pittsburgh PA
139 PM EDT Sat Sep 27 2025
.SYNOPSIS...
Rain showers south and east of Pittsburgh on Saturday. Dry and
unseasonably warm on Sunday and Monday. Low rain chances for
northern West Virginia early Tuesday but otherwise dry with a
cooling trend through the rest of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Showers continue southeast of Pittsburgh through this
  afternoon before clearing out tonight
- Patchy fog possible late tonight into early Sunday morning
---------------------------------------------------------------
A deep trough over the southeast CONUS lifts northeastward
towards the Mid-Atlantic coast through the near term as high
pressure builds into the region from the west. With this
pattern shift, the ongoing shower activity southeast of
Pittsburgh should diminish and move off to the east along with
the cloud cover that has covered most of the area. Lingering
low-level moisture, in combination with efficient radiative
cooling under clearing skies and drying mid levels, will allow
for patchy fog development overnight. Low temperatures continue
to trend around 5 to 8 degrees above seasonal averages, only
dropping into the mid to upper 50s in most places by early
Sunday morning.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
KEY MESSAGES:
- Dry and warm on Sunday and Monday
- Increased cloud coverage Monday
----------------------------------------------------------------
Ensembles support the upper low cutting off from the flow on Sunday
with height rises locally downstream of building ridging to our
west. Meanwhile, surface high pressure establishes across the Great
Lakes keeping us dry to close out the weekend and warmer than
Saturday with less cloud cover. It`ll be unseasonably warm with an
80+% chance of >80F for highs. Dew points should mix out some, but
it could still feel more like the mid 80s by the afternoon.
Still dry on Monday as the surface high gradually weakens but
remains in control. The only notable difference will be an increase
in cloud coverage from the southeast with moisture extending north
from now Tropical Depression Nine. Highs are thus likely to be a few
degrees cooler than Sunday, especially south and east of Pittsburgh
where cloud cover resides for more of the day.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
KEY MESSAGES:
- Uncertainty for the beginning of next week dependent on tropical
  low development and track
- Trend is toward a dry solution locally
-------------------------------------------------------------------
Eyes turn to the Atlantic at the beginning of next week with TD9 set
to approach the Carolinas by Tuesday and Hurricane Humberto
remaining well offshore. A complicated pattern evolves with synoptic-
scale interactions and how all of this may unfold with numerous
solutions still in play. The bottom line right now is that
notable impact to our area is not expected, and the trend
locally has been toward a drier one in the past 24 hours.
All ensembles support high pressure sinking south through Ontario by
mid-week, though differences in strength and timing of mid-level
waves lend some uncertainty to how quickly it builds and how strong
it is. The 24 hour trend has been toward a stronger, quicker
building high which favors a lean toward a drier, warmer solution
locally as TD9 turns east offshore of the Carolinas. The NBM
25th/75th MaxT spread Tuesday and Wednesday has shrunk now to around
5-7 degrees vs. the ten degrees 24 hours ago and is sitting in the
mid to upper 70s; primary uncertainty is stemming from question
regarding northward extent of cloud coverage from the system with
low end showing mostly sunny areawide and high end broken to
overcast. It still remains possible that TD9 gets absorbed by the
southeast CONUS trough/cut off low, very slowly meanders around the
coast, and extends moisture far enough north to bring some rain to
the southern part of our area on Tuesday. In this case, could see
mentionable PoPs extend as far north as Pittsburgh, but the latest
NBM follows trends of global ensembles and backs off rain mention
for nearly all of our area with only a slight chance creeping into
Preston/Tucker Counties.
With the increased cloud coverage, temperatures are likely to fall
off closer to normal (low 70s) by mid-week as the placement of the
surface high promotes cool, dry northerly flow. Rain chances through
week`s end are very low to nil as all ensembles exhibit good
agreement on the high sinking into the New England region and
strengthening as it does so. If you`re looking for more of a fall
feel, that should arrive to close out the week. Temps may moderate a
bit by next weekend.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Mainly high and mid level clouds have expanded across the area
this afternoon. Showers are ongoing in northern WV and the
higher elevations of SW PA, with limited impacts (MGW has
observed MVFR cigs/vis during periods of rain). This activity
will continue through the rest of this afternoon before tapering
this evening as the surface low supporting them tracks
away from the area towards the Mid Atlantic coast. With clearing
skies and lingering low-level moisture, patchy fog/stratus will
be possible overnight at most terminals. Improvement back to VFR
will be quick Sunday morning as dry air and high pressure build
into the area.
.OUTLOOK....
VFR returns under high pressure Sunday through mid week.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Cermak/MLB
NEAR TERM...Cermak/Shallenberger
SHORT TERM...MLB
LONG TERM...MLB
AVIATION...Cermak

NWS PBZ Office Area Forecast Discussion