322
FXUS61 KPBZ 051945
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
345 PM 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 /UNTIL 6 AM THURSDAY MORNING/...
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
through this evening ahead of a cold front. The mentioned shortwave
will cross the region late this afternoon. NBM is showing
higher probs for rainfall this afternoon over the ridges but the
warm rain process in effect throughout today will make just
about any area a concern for heavy rainfall. 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. For the
most part heading into the evening, there still appears to be
some instability as sfc based CAPE values remain in between 1000
and 2000 J/Kg across the area with at least some 30 knots of
bulk shear. The severe threat remain minimal but still possible.

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 /6 AM THURSDAY MORNING THROUGH FRIDAY/...
KEY MESSAGES:

- Risk for scattered showers/storms continues on Thursday with
  the passage of a deep trough.
- Continued 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. Thursday
afternoon seems to be a period to watch for as well with MU CAPE
values between 500 and 700 J/Kg with nearing 50 knots of shear.
SPC has a general thunder this day but there certainly could be
a strong storm with this passing post frontal trough.

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 and scattered showers.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
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 Friday night into
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.

The pattern will change by Tuesday next week as the upper low
finally gets shunted to the east with riding finally moving back
into the region. This will mean dry weather possibly returning
for Tuesday and Wednesday next week as rain chances remain below
30%.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Periodic MVFR cigs with scattered showers are expected through
the afternoon with increasing moisture and a crossing trough.
After a brief break this evening, showers and possibly a few
storms will accompany a cold front as it crosses the region. Mid
evening and overnight, MVFR and IFR probabilities are 70/80%
30/40% respectively with 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...22/Shallenberger
AVIATION...88