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479
FXUS61 KPBZ 052111
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
511 PM EDT Sun May 5 2024

.SYNOPSIS...
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Showers and thunderstorms will continue to impact the region
through the late evening. A few storms could be severe and
produce strong wind, hail, and heavy rainfall. Wet, warm
conditions are anticipated to continue throughout the week as an
elongated trough builds to our west and deep southwest flow
remains.
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&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
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KEY MESSAGES:

- There is a potential of strong to severe storm late this evening
  as as a weak cold front and shortwave cross into eastern Ohio
  and western PA.
- Along with severe winds, expected heavy rainfall rates with
  passing storms.
- Probability of severe to strong storms rapidly decreases after
  sunset with the loss of diurnal heating.
-------------------------------------------------------------------

A weak shortwave trough and cold front are currently tracking
through our region at the moment. A few pulse thunderstorms
could create gusty winds if icy cores develop aloft. Otherwise,
with marginal wind shear, high PWATs, and a saturated soil from
convection over the last 24 hours, isolated flooding could
impact the urban communities.

After 8pm the probability of severe storms rapidly decrease
with the loss of diurnal heating. Remnant showers and a few
isolated storms may linger passed midnight, which is expect to
be near the PIT vicinity.

Overnight temperatures will continue to remain above the
climatological average by 10 degrees.
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&&

.SHORT TERM /MIDNIGHT TONIGHT THROUGH TUESDAY NIGHT/...
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KEY MESSAGES:

- Light rain showers may linger along the Pennsylvania ridges
  through 6am Monday.
- Areas of fog may also develop along the Pennsylvania ridges,
  where sufficient moisture resides.
- Temperatures will remain above normal Monday.
- Convection will likely redevelop south of I-70 Monday
  afternoon/evening, along a stalled frontal boundary as a low
  pressure system passing to our south.

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A frontal boundary is expected to stall or move very slowly west
to east between PIT and the Laurel Ridges from midnight to
dawn Monday. An additional quarter of inch of sporadic
precipitation is expected during this time period. Along with
rain, areas of fog may develop east of PIT under light winds and
sufficient boundary layer moisture.

After dawn, Hi-Res model guidance suggest that the frontal
boundary will likely stall near or south of I-70. A passing
shortwave out of the Mississippi River Valley will near West
Virginia Monday afternoon, showers and storms will redevelop
south of Pittsburgh along the weak frontal boundary. Probability
of precipitation will remain low between Pittsburgh and I-80,
likely due to ridging over the Great Lakes filtering drier air
from the north.

The probability of severe storms will remain low despite MUCAPE
ranging between 700J/Kg to 1000J/kg during peak heating. Bulk
wind shear will only range between 20kt to 25kts and downdraft
potential will be low given shallow layers of potential dry air
available aloft.

A ejecting trough out of the Rockies into the northern Plains
and ridging over Florida will reinforce a surge of moisture into
the Ohio River Valley Tuesday under southwest flow. Severe
storms have the potential to develop Tuesday afternoon/evening
under a destabilizing airmass and effective shear rapidly
increasing from 20kts to 50kts just before sunset. The Storm
Prediction Center has noted the severe potential with issuing a
Slight/Marginal Risk for portions on Day 3. Based on model
soundings and hodographs, hail and damaging winds will likely
be the biggest threat.
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&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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KEY MESSAGES:

- Ridging over the Great Lakes is expected to reduce
  precipitation chances briefly Wednesday.
- A new disturbance is expect to return showers and
  thunderstorms late Wednesday night into early Thursday
  morning.
- Ensemble models suggest a very wet pattern into the weekend.
-------------------------------------------------------------------

An active weather pattern will remain in place for our region,
with decent daily precipitation chances through the weekend.
Therefore, flooding concerns will need to be monitor in the long
term.

The potential of a period of severe weather Wednesday
night into early Thursday with a passing disturbance will need
to be monitored closely. Organized convection could be
initiated if sufficient moisture advances north into the Ohio
River Valley. Confidence is high that the wind shear will be
available, it is a matter of destabilization that could pose a
problem for severe convection development.
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&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Surface heating across the area has resulted in the lifting and
scattering of ceilings across the area. However, some
intermittent ceilings of MVFR and IFR are still likely through
the afternoon. Specifically, FKL and DUJ will hover between
below IFR to IFR through much of the period due to the cooler
and more moist conditions in the north. Expect MVFR to VFR
across the rest of the terminals through the afternoon and
evening. Thunderstorms are expected to develop into the
afternoon with heating but expect coverage to be scattered. Cigs
are expected to crash again tonight behind the front with the
return of northwest flow.

.Outlook...
Some improvements to the restrictions are expected Monday with
influence of high pressure to the north, but shortwave movement
across the TN River Valley may maintain some
restriction/precipitation chances for southern terminals.

The rest of the week will remain active with varying periods of
precipitation and restrictions amid low pressure passage.

&&

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

&&

$$

SYNOPSIS...Hefferan
NEAR TERM...Hefferan
SHORT TERM...Hefferan
LONG TERM...Hefferan
AVIATION...Shallenberger