256
FXUS61 KPBZ 060011
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
811 PM EDT Fri Jul 5 2024

.SYNOPSIS...
Shortwave passage will create periods of moderate rain showers
with low probability thunder through tonight, along with a non
zero damaging wind and flood threat. Dry weather returns
Saturday through Monday with temperature rising well above
normal by Monday afternoon.

&&

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

- Shower and thunderstorm activity will become more widespread
  tonight, with a still-present risk of localized flash
  flooding. The risk of damaging wind gusts remains low.

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Only a few light rain showers are in progress across the
forecast area currently. SPC mesoanalysis and ACARS soundings
have shown little in the way of MLCAPE over the past few hours,
with a large portion of the area having 500 J/kg or less, along
with capping at around 800mb or so. This has prevented much of
any development to this point, let alone any severe weather
chances. Have reduced PoPs for the next couple of hours as a
result. A cluster of showers and thunderstorms has formed
further down the Ohio River in the RLX CWA, where some low-
level convergence and more favorable instability have fueled
thunderstorms producing heavy rainfall totals.

A shortwave is still progged to move through between 00Z and
06Z, which may yield a greater uptick of storm development
across western PA but with low probability of severe weather.
Flash flooding will remain possible as high PWAT persist, but
strong enough steering flow and relatively dry antecedent
conditions should keep risk low. Expect that the current
downriver activity will fade somewhat over the next couple of
hoers as it lifts northeast into a more hostile convective
environment, but a threat of localized downpours will persist.
Passage of a surface trough and upper wave will diminish
precipitation chances west to east and offer a slight reprieve
from the warm, muggy conditions.

&&

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

- Dry and more seasonable weather returns on Saturday.
- Rising temperature likely through Monday as dry weather
  persists.

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Drier southwest flow and ridging at the surface will support dry
weather Saturday. Lingering morning stratus clouds are expected
to break up with a scattered to broken cumulus field developing
in the late morning to early afternoon; weak cool advection plus
the cloud cover should aid temperature returning to more
seasonal values. More notably for some, drier air will mix to
the surface and bring relief to the region from the multiple day
experience of humid conditions.

Return flow as high pressure settles over the Atlantic will
support rising temperature Sunday into Monday as the next upper
trough system develops over the Central Plains. Heat risk
concerns return as a result, though probabilities of seeing heat
indices above advisory criteria remain low.

&&

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

- High probability for dry weather and slightly above average
  temperature the rest of the weekend.
- Unsettled weather returns Tuesday through at least mid-week.

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Ensemble consensus continues to favor an Upper Midwest trough
lifting through the Great Lakes region Tuesday into Wednesday
morning with a weak surface trough. Moist advection ahead of the
wave is likely to foster a warm, humid environment translating
to likely showers and thunderstorms ahead of the feature.
Environmental conditions remain varied, but with ensemble means
showing near 90F highs and 70F dewpoints, there appears to be at
least a low probability for flash flood risk and potential other
severe hazards.

Variations become post-shortwave passage depending on high
pressure strength to the north as well as potential pattern
impact from the remnants of Hurricane Beryl. The main takeaways
for the long range period is that 500mb mean heights suggest a
continuation of near to above normal temperature and
precipitation chances tied to shortwave movement.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Remnant showers from a passing MCS in northern WV will briefly
impact MGW (and potentially LBE) through 03Z. A brief period of
MVFR to IFR vis may occur with convection. Otherwise, scattered
showers north of MGW will continue to pass slowly from west to
east ahead of a cold front.

Cigs should lower to MVFR/IFR early Saturday morning with
lingering low-level moisture; ZZV may experience MVFR to IFR fog
between 09Z to 12Z if the cold front tracks through eastern
Ohio before dawn.

VFR conditions increase between 13Z to 16Z with diurnal heating
and building high pressure. Scattered VFR low- lvl cu will
likely develop with mixing of the boundary layer after 15Z.

.Outlook...
VFR conditions should persist into Sunday under high pressure.
The next chance for widespread restrictions will be with our
next system Tuesday.

&&

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

&&

$$

SYNOPSIS...Frazier
NEAR TERM...Frazier/CL
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...Hefferan/88