470
FXUS61 KPBZ 041119
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
719 AM EDT Fri Jul 4 2025

.SYNOPSIS...
High pressure is favored to promote dry weather with slowly
rising temperature through Sunday. A series of upper level
shortwaves starting late Sunday will create periodic
thunderstorm chances for much of the upcoming week.

&&

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

- Dry and sunny weather for the Fourth.
---------------------------------------------------------------

High pressure has now settled into the region centered over the
Middle Atlantic that will promote dry weather and mostly sunny
skies, save for some potential increasing high clouds from
convection northwest of the region.Temperatures will warm to a
few degree above normal for highs today given the sunny skies
and dry conditions. Did populate the 10th percentile dew points
for today given the dry trend.

Heading into the overnight tonight, once again, there will be
another chance of some river valley fog to develop though
increasing high level clouds may limit development. Low
temperatures tonight will remain near average.

&&

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

- Chance for fog on Friday and Saturday mornings.
- Temperatures above average.

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With ridge aloft and southerly flow, conditions on Saturday
should boost area highs into the upper 80s to near 90F. NBM
probs for 90F are highest across eastern Ohio, northern West
Virginia panhandle, and the Pittsburgh urban heat island
(50%-75%). For Lawrence, Beaver, southern Armstrong, and
northwestern Westmoreland counties, probabilities for 90F are
generally around 20%-30%. Outside of these regions, the
probability for these temperatures are lower with no chance in
most of the areas along the Appalachian Mountains.

On Sunday, the ridge is forecast to further flatten with
westerly flow aloft across the Upper Ohio Valley region. The 500
mb heights are expected to approach 590 dam, maintaining hot
conditions across the region. There is a high probability across
most of the region (75%-95%) that maximum temperatures reach or
exceed 90F. The heat indices remain in the 90s, so there is a
low chance for a Heat Advisory being issued.

&&

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

- Shower and thunderstorm chances returning Sunday night and Monday.
- Increasingly hot and humid conditions on Monday
- Post frontal rain chances remain on Tuesday and Wednesday.
-------------------------------------------------------------------

With the flattened ridge, disturbances embedded in the flow aloft
are expected to periodically cross the region, with daily shower and
thunderstorm chances returning. Thus, will expected showers and
thunderstorms to develop Sunday night.

On Monday, 500 mb heights are still expected to be around 590 dam,
allowing hot and humid conditions to persist across most of the
region. High probability (60%-75%) of maximum temperatures at or
above 90 degrees. The chances of Heat Advisory criteria remains low
as heat indices remain in the 90s.

Temperatures are expected to relax for the Tuesday and Wednesday
period due to the passage of a cold front Monday night. This will
allow cooler air into the region with the potential of some
lingering chances for precip behind the front. The front is
expected to lift back north as precip potential continues on
Thursday.

&&

.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
High confidence in VFR through the TAF period under the
influence of high pressure with a generally light afternoon
northwest wind and a few diurnal cu.

A slight influx in high level clouds overnight from convection
north of the region should limit pre-dawn valley fog.

Outlook...
VFR under the influence of high pressure is favored through
Sunday afternoon.

Hi-res modeling suggests a low end (20-30
percent) potential for convection to trickle towards FKL/DUJ
Saturday afternoon in association with a shortwave rounding the
upper level ridge. Otherwise, late Sunday into Monday will be
the period where shower and thunderstorm chances increase with
the approach of an upper shortwave and surface frontal boundary.
Ensemble models favor an active weather week with restrictions
mainly tied to convective activity.

&&

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

&&

$$

SYNOPSIS...Shallenberger
NEAR TERM...Shallenberger
SHORT TERM...Shallenberger
LONG TERM...Shallenberger/Lupo
AVIATION...Frazier