Mount Lebanon, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

571
FXUS61 KPBZ 021220
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
820 AM EDT Mon Jun 2 2025

.SYNOPSIS...
Rising temperature is likely through Wednesday along while being
precipitation free. Lofted wildfire smoke may hamper the degree
of heating while potentially reaching the lower levels Tuesday.
Shower and thunderstorm chances are likely to return late in the
week.

&&

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

- Dry weather persists but lofted wildfire smoke may limit total
  heating
-------------------------------------------------------------------

The Upper Ohio River Valley will continue to see height rises
aloft as the New England trough slinks farther east and ridging
nears from the Central Plains. High pressure at the surface will
help ensure dry weather with abundant sunshine (see disclaimer
below) as areal high temperature trends another 5 to 8 degrees
warmer than Sunday. Overnight low temperature will see similar
rises despite potential for another strong radiational cooling
night.

Disclaimer: outside of a few afternoon cumulus, skies are
highly likely to be free of clouds. HOWEVER, as was seen Sunday,
the upper level pattern will continue feeding Canadian wildfire
smoke overhead as HRRR modeling suggests its thickness being
similar to Sunday but spreading over the entire region. Looking
at climate site readings, this layer seemed to cool daytime
highs ~2 degrees from model mean values; a similar reduction in
ensemble model means was applied to the high temperature
forecast for today. There is some insinuation that smoking
mixing to the surface cold occur late in the day in northwest PA
(leading to more surface-based haze), but it appears too
localized for forecast mention. Overnight low temperature into
Tuesday morning may be more mild as well (forecast trends this
way) as thicker elevated smoke limits the degree of radiational
cooling.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:

- Rising temperature continues with ensembles favoring Wednesday
  for its peak.
- Impacts of wildfire smoke may increase Tuesday into Wednesday.
----------------------------------------------------------------

There is high confidence in notable upper level ridging to shift
overhead Tuesday and position over the Atlantic Coast Wednesday.
These height rises (Tuesday) and increasingly warm/moist
southwesterly flow (Wednesday) will continue the region`s trend
of rising temperature while keeping the area precipitation free.
Ensembles suggest high temperature is likely to peak Wednesday,
with 60-90% probabilities for valleys and urban areas from
Pittsburgh west seeing maximum temperature hitting/exceeding 90
degrees. If this occurs, heat risks will rise and would warrant
properly planning to mitigate its impacts if you have outdoor
plans.

Like the prior section, the impacts of wildfire smoke could
dampen the degree of rising temperature and cause many areas to
fall short of 90 despite those high probabilities. HRRR modeling
suggests that far eastern OH through western PA could see smoke
mixing down to the surface by Tuesday afternoon; similar model
outputs of this variable yielded generally 4 to 6 mile
visibilities across Minnesota/Iowa Sunday afternoon. Given that
verification, the forecast now includes the mention of haze due
to the likely presence of wildfire smoke Tuesday afternoon. This
could continue into Wednesday, but the lack of smoke modeling
out that far limits confidence to add it into the forecast.

Visit airnow.gov or your states department of environmental
services to better understand the potential impacts of wildfire
smoke levels.

Shortwave movement over the western Great Lake may nudge showers
and thunderstorms far enough east Wednesday night to reach the
far northwest forecast zones. However, the more likely scenario
is increased cloud coverage before chances rise Thursday.

&&

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

- Shower and thunderstorm chances increase heading into the
  weekend
- Any hazardous weather may be predicated on upstream convective
  evolution
-------------------------------------------------------------------

Ensemble models favor the movement of multiple shortwaves over
the top of the southeast CONUS ridge Thursday through Saturday
that will slowly shunt it move over the Gulf States. Each wave
is likely to promote showers and thunderstorms but timing and
storm evolution variances remain large and somewhat predicated
on upstream convective evolution. The general expectation would
be to see periods of showers/thunderstorms with chances peaking
around Saturday with a potential trough axis crossing while
temperature trends toward seasonal averages.

The lack of strong flow during this period and complications of
upstream convection make analysis of hazardous weather potential
difficult. That said, the broad setup of a ridge breakdown can
be a precursor to severe weather and bares monitoring as the
period of note approaches.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
VFR conditions continue through the forecast TAF period with the
only possible hindrance to this being wildfire smoke lowering
visibilities. Patchy valley fog has been seen across the region this
morning but no impacts to any ports has been noted. Winds remain
light and generally westerly through the day.

Models continue to indicate increasing wildfire smoke concentrations
over the coming days. Impacts today are expected to be light as much
of the smoke remains elevated but RAP smoke runs point towards
quickly increasing levels of near-surface smoke by 18z Tuesday,
which could impact VIS.

Outlook... High pressure and ridge building near the region is very
likely to maintain general VFR through Wednesday, with surface wind
generally light until Wednesday afternoon (breezy SW wind as the
surface high shifts).

Near-surface wildfire smoke densities are likely to increase on
Tuesday with impacts to surface visibility. Estimates are generally
a 4-6SM haze with thicker smoke.

The next potential impact period will be late week when shower and
thunderstorm chances increases (and restrictions mainly tied to
convection) as a series of shortwaves cross over the ridge axis.

&&

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

&&

$$

SYNOPSIS...Frazier
NEAR TERM...Frazier
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...Rackley/AK