426
FXUS61 KPBZ 301137
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
737 AM EDT Mon Jun 30 2025

.SYNOPSIS...
Scattered showers and thunderstorms are expected this
afternoon and again on Tuesday. A few storms could produce
damaging winds and localized flooding.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Patchy fog possible this morning.
- Strong to severe thunderstorms and heavy rainfall possible
  this afternoon

---------------------------------------------------------------

Radar shows a few isolated, light showers across the region,
primarily over Ohio. These will continue to be possible through
the early morning, but are relatively low probability.
Otherwise, mostly dry weather continues into Monday morning. Low
temperatures will drop into the upper 60s to lower 70s. Patchy
fog will also be possible, but increasing cloud cover will
preclude this from being widespread. Probability for this is
highest south of Pittsburgh near the stationary boundary.

After a single quiet day, the currently-stalled frontal
boundary will lift northwards today as a warm front, forcing an
increase in area showers and thunderstorms by this afternoon.
The environment will to similar to what we saw Friday and
Saturday -- namely high, tall/thin CAPE and weak shear. The
main notable difference is a general lack of dry air aloft. This
could inhibit a more widespread downburst threat. Still,
increasing mid-level shear during the afternoon should be enough
to support stronger updrafts and a few isolated severe
thunderstorms. Damaging wind gusts will be the primary hazard.
SPC has maintained a marginal risk for damaging wind across the
area.

After what seems like a month of rain, isolated flash flooding
will again be on the table, particularly over urban areas.
Isolated storms will be capable of producing rainfall rates that
exceed 1 in/hr, and and backbuilding storms may quickly
exceed flash flood guidance. WPC has maintained a marginal risk
for excessive rainfall.

Temperatures remain several degrees above seasonal average.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:

- Strong to severe storms and heavy rainfall chances Tuesday
- Temperatures remain above-average, but below Heat Advisory
  criteria.

----------------------------------------------------------------

Convective activity is likely to wane through the evening with
loss of daytime heating. Humid conditions will keep overnight
lows warm once again.

A cold front and accompanying trough will cross the region on
Tuesday. Though fropa timing remains a bit uncertain, CAMS agree
on more organized convection along and ahead of the front
Tuesday morning/afternoon. With deep tropical moisture in place,
heavy downpours are again expected, but more progressive storm
motion should help reduce the flooding risk. SPC has maintained
a marginal risk for the southeastern half of the area. This will
of course depend on the exact timing of the front. Slower
frontal passage will likely lead to expansion farther northwest.

Clearing will quickly commence behind the cold front, with dry
and mostly sunny weather as we head into Wednesday. Dry
advection behind the front will help lower our dew points and
allow overnight temperatures to drop more squarely into the
mid-60s, but afternoon highs will remain several degrees above
average.

&&

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

- Cold front Thursday returns shower and storm chances.
- Dry for Independence Day.
- Rain chances return late next weekend.
-------------------------------------------------------------------

A shortwave will churn through the ECONUS longwave trough on
Thursday and kick another cold front through the area from the
northwest. Timing remains a bit uncertain, but passage is likely
some time on Thursday which will return the chance for showers
and storms, especially during the afternoon. Dew points ahead
of it look to sit in the low 60s with not much return flow on
Wednesday, but the NBM prob for >1000 J/kg SBCAPE is around
40-50% in the afternoon hours. Deep layer shear may be the
lacking component with the best forcing and flow displaced to
the north with the shortwave. Still, machine learning does peg
at least a low-end chance of severe weather with the passage,
contingent on it being at a favorable diurnal time.

Ensembles remain confident in a dry Fourth of July as mid-level
ridging returns behind the departing longwave. 5 or so degree
spread in high temperatures remain (between low 80s and upper
80s), due to subtle timing differences in how quickly the ridge
builds.

The ridge flattens out into the weekend with mid-level zonal
flow taking over. Ensembles do agree on low pressure
development across the Northern Plains sometime Friday into
Saturday and quickly sliding east, but disagreement on timing
lends low confidence precipitation chances locally as the
attendant surface cold front follows along with it. Most of
Saturday looks dry at this time with even the faster solutions
holding precip chances off until early Sunday, so most likely
will see a more unsettled pattern return for the latter half of
the weekend and into next week. Temperatures linger around
average through the second half of the week, but may warm to
slightly above average for the weekend.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A few showers may impact ZZV and FKL this morning, otherwise
most TAF sites are expected to remain VFR underneath mid and
upper level cloud cover. A couple of thunderstorms over eastern
Ohio should largely avoid TAF sites this morning.

The old stubborn boundary to our south will lift back north
today as a warm front, once again providing a very rich moisture
environment. Diurnal cumulus will begin to pop later this
morning as low level lapse rates start to steepen and as
convective temperatures are reached.

Numerous showers and thunderstorms are expected to develop by
early to mid afternoon as a shortwave trough crosses the Upper
Ohio Valley region, and as a surface boundary lifts north. CAPE
is expected to range from 1000-2000 j/kg as the wave crosses,
with 0-6km shear near 40kt. Included TEMPO for thunderstorms at
all airports for the most likely time of occurrence, with PIT
generally 19Z-23Z. Included MVFR restrictions for now, though
IFR will be possible in locally heavy rainfall.

Convection should gradually wane this evening with the loss of
diurnal instability, and as the shortwave exits. Lingering low-
level moisture will lead to an MVFR/IFR stratus deck overnight,
with enough mixing remaining to keep widespread fog from
developing.

Outlook...
A crossing cold front will result in numerous showers and
thunderstorms again on Tuesday afternoon and evening. VFR
returns Wednesday under high pressure, before restriction and
thunderstorm potential returns with a Thursday cold front. VFR
is expected again by Friday under high pressure.

&&

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

&&

$$

SYNOPSIS...Rackley
NEAR TERM...Rackley
SHORT TERM...Rackley
LONG TERM...Rackley/MLB
AVIATION...WM/CL