848
FXUS61 KPBZ 051431
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1031 AM EDT Wed Jun 5 2024

.SYNOPSIS...
Widespread showers and storms return today. Unsettled weather
will remain into the weekend. Cooler temperatures return Friday
and hold through the weekend.

&&

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

- Shower and storm chances increase today with the passage of an
  upper level wave.
--------------------------------------------------------------

Another shortwave trough is expected to traverse the area this
afternoon and evening ahead of a cold front. Before this
afternoon`s feature, a weak trough is currently exiting the area
leaving some thick cloud cover in place through the early part
of the day.

The mentioned more significant shortwave will cross the region
this afternoon with its focus on locations south and east of
Pittsburgh. NBM is showing higher probs for rainfall this
afternoon over the ridges. Latest CAM models are also
broadcasting the more likely place for stronger afternoon
convection and heavier rain east of PIT. Its also worth
mentioning that PWATs seem to be elevated for the amount of
moisture in place. The 12Z morning PIT sounding shows 1.66 PWAT
and a freezing level at 12 KFT with a good bit of the SFC to
500MB being saturated. Instability will be descent this
afternoon, but strong wind shear will be lacking. What shear is
available will ride up along the higher elevations ahead of the
shortwave. Cloud cover and warm air aloft will be limiting
factors today as well. To that fact, the tornado 2% has been
removed by SPC and only a wind and flood threat remain.

A cold front will cross our area late tonight with the potential
for additional convection through the overnight. This should
keep fog at a minimum but also temperatures will be warm
overnight with the persistent cloud cover. Lows will remain in
the middle 60s for low tonight.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
KEY MESSAGES:

- Risk for scattered showers/storms continues on Thursday with
  the passage of a deep trough.
- More activity on Friday with cooler temperatures.

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

Lingering showers/storms will end Thursday morning as the cold
front exits to the east. A deep shortwave trough is expected to
swing through Thursday afternoon. This will likely return
showers and storms Thursday afternoon/evening.

Just above-average highs expected Thursday.

Highly anomalous upper level low will move across the Great
Lakes on Friday. Waves of energy will swing around the low as
will much cooler air. This will keep our weather unsettled on
Friday. Temperatures should be noticeably cooler Friday with
plenty of clouds, scattered showers and 850T of +5 to +9. Will
go with NBM 10th pct for highs Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
KEY MESSAGES:


- Periodic showers with cooler conditions are expected through
  the weekend with a slowly crossing upper-level low.

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

The upper-low will dig into New England by Saturday. This will
keep cooler and showery conditions in the forecast as we head
into the weekend and into early next week. While there is low
confidence on pinpointing the best timing of these showers each
day, ensembles do agree on the general showery pattern with
upper troughing persisting through the weekend and possibly into
early next week.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
Scattered showers are expected to move across the region through
the TAF period with increasing moisture and ascent ahead of an
approaching shortwave trough and surface cold front. Outside of
any brief and localized MVFR restrictions in showers, widespread
MVFR cig restrictions should hold off to mid evening and
overnight ahead and along the front. MVFR and IFR probabilities
are 70/80% 30/40% respectively. Improvement expected in the
morning as drier air moves in behind the front.

Best chance for any thunder will be during the afternoon mainly
east of KPIT and possibly along the front overnight. Instability
is marginal, but should be sufficient for a few rumbles of
thunder.

.Outlook...
Periodic restrictions and scattered showers are expected
Thursday through Sunday as a slow moving upper low persists
across the Great Lakes region.

&&

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

&&

$$

SYNOPSIS...Shallenberger
NEAR TERM...Shallenberger
SHORT TERM...22/Shallenberger
LONG TERM...Rackley/22
AVIATION...88