Mount Lebanon, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

751
FXUS61 KPBZ 270851
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
451 AM EDT Fri Jun 27 2025

.SYNOPSIS...
Hot and humid through the end of the week with daily afternoon
storm, isolated flooding, and severe wind chances. Rain chances
decrease Sunday, followed by another active period Monday to
Tuesday before temperatures return to near normal and conditions
trend slightly drier mid-week.

&&

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

- Heat concerns continue through the afternoon for most of the
  area, with indices approaching 100F, hottest for valley and
  urban locations.
- A marginal chance of severe wind and a slight risk of flooding
  into the afternoon and evening with downburst potential.
---------------------------------------------------------------

The current conditions feature some stratus across the area as
plenty of moisture remains from the activity over the past
couple of days. Will expect some patchy fog development through
the morning hours and mainly over the river valleys. The lows
are still well above normal despite the slightly cooler
conditions. Heading into the day, the overall pattern still
features the 500MB ridge still centered over the Carolinas with
return flow continuing into the Middle Atlantic States. This
will once again set the stage for afternoon thunderstorm
development. The boundary that remains over the north will begin
to align along the ridges to the east.

This will put the Southwest PA and northern WV region in the
warm sector and most and thus in the axis of moisture advection.
This is the reason that a slight risk for excessive rainfall
has been issued along the ridges in PA and south into the WV
ridges. This area has been hit hard over the last 2 days and
will likely mean lower FFG. The NBM probs for 1 inch of rain
over a 24 hour period features some probs over 50% over SW PA
and along the ridges. Here, with the likely lower FFG values,
will expect some issues flooding again. Over to the severe side
of the house, a wind threat across the entire forecast area
seems likely again. In fact, the NBM probs are giving a 80% to
90% prob of SB CAPE values over 1500 J/Kg. This in conjunction
with DCAPE values again today into the 750 to 1000 J/Kg range.
This will lead to another day of downburst potential. Most
convection should initiate today by the 18Z to 20Z timeframe
and will likely go into the evening hours of the day. Another
day of Heat indices over 100 degrees will be likely and thus the
Heat Advisory is in effect for one more day.

Heading into the overnight, will expected some lingering
convection from the evening, but most of the severe threats
should come to an end by the 00Z to 02Z period. A few instances
of flooding may need addressed as well but most of the impacts
should come to an end by 06Z. Some instances of fog development
is expected through the dawn hours as well.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
KEY MESSAGES:

- Downburst wind and flooding threats in the afternoon and
  evening continue on Saturday.
----------------------------------------------------------------

For Saturday, a boundary sinking from the north in a similar
environment will continue to allow for downburst wind and
flooding threats. LREF mean analysis shows 1500 J/kg MLCAPE, 650
DCAPE, and PWATS back up near 1.8" to 1.9" in moisture pooling
along the boundary. Perhaps given the environment and slow
southward sagging boundary, flooding threats may be a bit higher
than days prior, depending on the coverage, with increased
training potential. A lull in convection is expected Saturday
night with the potential of fog development.

The boundary is forecast to sag south on Sunday with ML
techniques suggesting lower probabilities of severe weather, and
any chances of flooding most likely for northern West Virginia
in the vicinity of the boundary. Again, some patchy fog
development is possible Sunday night.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
KEY MESSAGES:

- Potential for storms and locally heavy rainfall through at
  least Monday and possibly on Tuesday.
-------------------------------------------------------------------

For Monday, at least some return flow is expected as the
boundary draws back north. Southwest flow prevails with
increasing precipitation chances yet again as temperature
spreads are mostly encompassed in the upper 80s to low 90s. Once
again, this will allow more wind and flooding threats.

A frontal passage is forecast sometime late Monday into Tuesday
that will maintain flooding chances before a cold front finally
clears the oppressive airmass out with a return to more normal
temperatures and moisture for mid-week. Clusters indicate this
pattern change, at least temporarily, is high confidence.

The Day 6 and 7 period for Wed and Thu highlight the return of
high pressure and a brief break in the constant daily
convection. Temperatures will also return to a more normal value
as well.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
Storms have diminished this evening, though a few light showers
remain. MVFR/IFR fog/stratus is possible in the early morning
with lingering low-level moisture, especially in locations that
received ample rainfall. MVFR to IFR ceilings are likely to
remain for DUJ through much of the period, but general VFR is
expected elsewhere.

Scattered to numerous showers and thunderstorms are expected to
fire after 18z again today, with localized potential for
restrictions. Ceilings will lower from the east Friday night,
generally impacting terminals north and east of PIT.

Outlook...
More numerous showers and thunderstorms are expected
Saturday afternoon and evening as the front wavers across the
region. There is a lesser potential for afternoon showers/storms
on Sunday as high pressure briefly brushes by to the north.
Showers/storms return again Monday with an approaching cold
front.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 8 PM EDT this evening for PAZ013-014-
     020>022-029-031-073-075.
OH...Heat Advisory until 8 PM EDT this evening for OHZ039>041-
     048>050-057>059-068-069.
WV...Heat Advisory until 8 PM EDT this evening for WVZ001>004-012-
     021-509-510.

&&

$$

SYNOPSIS...Shallenberger
NEAR TERM...Shallenberger
SHORT TERM...Shallenberger
LONG TERM...Milcarek
AVIATION...Rackley