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706
FXUS61 KPBZ 260902
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
502 AM EDT Sun May 26 2024

.SYNOPSIS...
Thunderstorms should gradually diminish and end this evening
with areas of fog forming after midnight. Sunday is expected to
be mostly dry under high pressure, but thunderstorms will
returning Sunday night into Memorial Day. As we flip the
calendars to June, temperatures fall back to just below normal.

&&

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

- Widespread dense fog through dawn. Dense Fog Advisory in
  effect.
- High pressure returns dry, warm weather for today.
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The showers and thunderstorms moving through the area have
pushed off to the southeast and weakened through the early
morning hours. As cloud cover begins to clear out, expect the
light winds and saturated ground to continue to assist in fog
development. Will likely need to extend the Dense Fog Advisory.

Flat upper ridging builds for today as surface high pressure
arrives in the wake of the departing cold front. This will be
the best day of the holiday weekend with little noticeable
difference in the airmass behind the front as NBM probability
for >85F is 40-60%.
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&&

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

- Another round of potentially strong to severe thunderstorms tonight
  into early Monday morning, then Monday afternoon
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A warm front approaches late in the evening as low pressure
ejects out of the Plains. Increasing moisture in developing
southwest flow aloft will overspread mid/upper level clouds by
evening. Latest guidance has continued the trend noted in the
last update with slightly slower progression and onset not until
late evening/overnight. While this timing is not typically
favorable for severe weather in our area, a strengthening
30-40kt low level jet across the area late tonight may help
maintain several stronger storms with damaging wind and/or large
hail into eastern Ohio. Thus, the western couple teirs of OH
counties in the forecast area have been upgraded to a slight
risk, (2 of 5) with the rest of the area in a Marginal risk (1
of 5).

Ensembles indicate only slight deviations from the mean in regard to
the depth of an upper trough and additional shortwave energy
traversing an upper low spinning across the Great Lakes through
Monday. Aided by daytime heating and slow passage of a cold front,
yet another round of strong to severe thunderstorms is possible with
our area again outlined in a Marginal Risk with just a few
eastern counties in a Slight risk. Machine learning comes a bit
more aggressive with an extension of severe probabilities back
into our area from the east, but one potential limiting factor
may be morning cloud cover as NBM spreads pin even 60-70%
coverage on the low end of the distribution. Highs Monday will
be thus be cooler than those over the weekend with mid 70s most
likely. The periodic chances of rainfall through the weekend may
lead to a greater flash flood threat with saturated soils across
the area.
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&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
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KEY MESSAGES:

- Periodic rain chances continue through midweek.
- Dry weather favored to close out the week.
- Temperatures fall back toward seasonal average.
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Upper level troughing plagues the area into mid week and rain
chances continue into next week, although coverage should be
scattered and mostly diurnally driven aside from a secondary cold
front crossing the region Tuesday. By Wednesday, ensemble
disagreement increases with the axis and strength of the upper
trough, but any flavor of solutions doesn`t kick it out of the
eastern CONUS until toward next weekend. Broad surface high pressure
should finally turn the area dry by late week while temperatures
fall back towards seasonal average with lows in the 40s not out of
the question come mid to late week as the cooler airmass settles in.
The dry change of weather is expected to last into the coming
weekend.
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&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
Widespread fog is expected through the early morning hours,
developing slowest across MGW/LBE where low clouds will linger
longest. Rapid burnoff after sunrise will result in VFR
returning thereafter and lasting well into the afternoon.

Restrictions may return with late afternoon/evening
thunderstorms with a crossing shortwave.

.Outlook...
Restrictions will likely linger through Monday morning with
continued showers and thunderstorms, eventually lifting to VFR
Monday afternoon. Restrictions with precipitation are then
expected periodically through mid-week.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
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PA...Dense Fog Advisory until 8 AM EDT this morning for PAZ007>009-
     013>016-020>022-029-031-073>078.
OH...Dense Fog Advisory until 8 AM EDT this morning for OHZ041.
WV...Dense Fog Advisory until 8 AM EDT this morning for WVZ001>004.
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&&

$$

SYNOPSIS...Craven/Shallenberger
NEAR TERM...Craven/Shallenberger
SHORT TERM...MLB/Shallenberger
LONG TERM...MLB/Shallenberger
AVIATION...Rackley