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994
FXUS61 KPBZ 310114
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
914 PM EDT Thu May 30 2024

.SYNOPSIS...
Dry weather and moderating temperature are expected through
Saturday under the influence of high pressure. Late Saturday
through early next week will feature scattered showers and
thunderstorms. Temperatures climb back above normal early next
week with lower to mid 80s forecast.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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KEY MESSAGES:

- Clear skies under high pressure
- Mid/upper 30 lows forecast tonight across the higher terrain
  and I-80 corridor.
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The latest surface analysis shows high pressure centered across
the Great Lakes region. The 00Z upper air charts shows a mid and
upper level trough across much of the NE CONUS, though a lack of
moisture precluded any significant cloud cover or precipitation.

The 00Z PIT sounding shows dry air through the entire column.
Efficient radiational cooling is expected tonight with the dry
air and clear skies in place. In addition, wind should become
calm overnight as the high builds further eastward. Maintained
the Frost Advisory as is for eastern Tucker county, with some
patchy frost surrounding the advisory area, and in Forest
county PA. Coverage of the frost outside of the advisory should
be patchy and limited. Overnight lows should br in the lower to
mid 30s across eastern Tucker county, with upper 30s to lower
40s elsewhere. Went with the lower 10th percentile of the NBM
guidance for lows with the efficient radiational cooling
expected.
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&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
KEY MESSAGES:

- Dry weather persists with moderating temperature.

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Little sensible change in pattern is expected on Friday as the
ridge axis slowly creeps east across the Great Lakes and into
the Ohio Valley. After a cool start to the morning, high
pressure will sunny skies will allow temperatures to moderate
back to near normal Friday afternoon. Much of the area is
forecast to hit mid-70s Friday afternoon.

The ridge axis will cross the CWA Friday night as surface high
pressure begins to shift east. This will boost southerly return
flow into Saturday ahead of our next system. The result will be
gradually increasing cloud cover through the day Saturday, with
afternoon temperatures pushing into the lower 80s outside of the
I-80 corridor and ridges.

A few showers may be creeping into our far western zones near
ZZV by late afternoon Saturday, but for now, timing for rain
with the next system appears to be later overnight into Sunday.

&&

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

- Shower and thunderstorm chances return Saturday night.
- Periodic rain chances are then expected for much of next week.
- Temperatures rebound back toward normal by Saturday.
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There is good ensemble agreement in the aforementioned ridge
shifting east on Saturday as shortwave troughing crosses into
the Ohio Valley. This shortwave will cross our area overnight
into Sunday, with a weak low and cold front at the surface.
Showers and thunderstorms are expected by Saturday night,
lingering through Sunday. Nocturnal arrival and excessive cloud
cover Sunday should keep lightning probabilities lower (along
with severe threats). Clouds and rain will also keep afternoon
temperatures a bit cooler on Sunday.

Quick passage of the trough should lend to broad ridge
development just south of the region Monday into Tuesday. This
synoptic pattern would favor above normal temperature with low
probability afternoon thunderstorms that will be predicated on
shortwave movement and convective evolution over the western
Great Lakes. Much variability in outcomes is seen within model
ensembles, which muddies any chance of entertaining severe
probabilities.

There is growing consensus on the development of a notable
upper low pressure system mid to late week that would pose a far
greater probability for convective development and, to some
extent, severe chances. However, there remains high uncertainty
in the timing and eventual evolution of that system.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
A prolong period of VFR conditions is expected under high
pressure through Saturday. FKL may experience a period of early
morning fog with radiational cooling between 10Z to 12Z Friday.
However, confidence is not high on this scenario; probability of
occurrence noted in the Hi-Res guidance is less than 20%.

.Outlook...
The potential for flight restrictions returns late Sat and Sun
with crossing low pressure.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...Frost Advisory from 2 AM to 8 AM EDT Friday for WVZ514.

&&

$$

SYNOPSIS...Frazier
NEAR TERM...WM
SHORT TERM...Rackley
LONG TERM...Rackley/Frazier
AVIATION...Hefferan