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873
FXUS61 KPBZ 011147
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
747 AM EDT Wed May 1 2024

.SYNOPSIS...
The remainder of the work week will be dry and warm. A slight
cool down is expected this weekend with returning rain chances.

&&

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

- Warm and mostly sunny today under building high pressure.

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Update focused on adjusting fog coverage for the next few hours,
as well as tweaks to hourly temps and dewpoints. Full sun and
the onset of mixing will dissipate fog by 14Z. Otherwise, warm
and dry weather is in store today with a weak upper ridge
building overhead. Temperatures climb to around 80 degrees under
mostly sunny skies and light winds.
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&&

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

- Dry weather and above-normal temperatures continue through
  Thursday.

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Dry weather and above-normal temperatures continue tonight into
Thursday. A weak front pushes into the area from the northwest
overnight but only brings a wind shift as convection will
struggle to develop given the lack of moisture and ascent
beneath the upper ridge. Temperatures settle into the 50s by
early Thursday morning before climbing back into the 80s (upper
70s north of I-80) Thursday afternoon.

&&

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

- An unsettled pattern returns Friday through the weekend with
  above-average temperatures and periods of showers and
  thunderstorms favored.

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High pressure will continue to support above-normal temps and
dry conditions Thursday night with lows ranging from upper 50s
south of I-80 to low 50s farther north.

Ensembles continue to indicate a more active weather pattern
setting up Friday into the weekend as an upper level trough
pushes eastward over the Great Lakes, shunting the ridge axis
southeastward and bringing a deep-layer southwest flow to the
region. Periods of showers and thunderstorms can be expected
Friday afternoon through the weekend, though exact timing and
intensity of any given round of convection remains uncertain
due to the complex nature of the more active pattern. The
latest ensemble runs continue to paint Friday night and
Saturday as the most likely periods to see widespread shower
and thunderstorm activity, though there also continues to be
some signal for scattered convection lingering through Sunday
and even into early next week.

At this time, a widespread severe weather threat appears
unlikely due to a lack of notable instability or bulk shear. The
same can be said about the threat for a widespread flood
threat, as ensemble probabilities for widespread rainfall
amounts of an inch or greater remain low (30% or less) across
the area during any given 24-hour period this weekend. That
said, heavier rain rates in thunderstorms could result in a
localized minor flood threat for low-lying and urban areas. For
this reason, the Weather Prediction Center has highlighted a
Marginal Risk for excessive rainfall across eastern OH, western
PA, and northern WV on Saturday. Stay tuned for more details on
timing and impacts as we get closer to the weekend.

As for temperatures, Friday continues to look like the warmest
day of the week, with highs potentially reaching the mid to
upper 80s across much of the area. Ensembles guidance continues
to indicate a 70% or greater chance of exceeding 85 degrees for
areas south of I-80. Temperatures Saturday through Monday also
trend above normal, but remain in the 70s due to thickening
cloud cover and an increasing coverage of showers and storms.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
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Areas of LIFR fog and stratus were in place at 1130Z, with
terminal impacts at LBE, HLG, and MGW, generally where previous
hi-res model guidance depicted it. With full sun and daytime
mixing commencing, VFR conditions will return between now and
14Z, with southwest wind of around 10 knots forecast by late
morning.

VFR conditions are then forecast to persist through the
remainder of the forecast period, with only patches of mid and
upper cloud expected. A repeat fog performance tonight is
currently not expected according to current guidance. Even 5
mile visibility has less than a 20 percent chance of occurrence
according to both HREF and NBM guidance.

.Outlook...
VFR conditions are expected to continue into Thursday under high
pressure. The next chance for restrictions comes late Friday
into early Saturday with passing low pressure.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...Cermak/Milcarek
NEAR TERM...Cermak/CL
SHORT TERM...Cermak/Milcarek
LONG TERM...Cermak
AVIATION...MLB/CL