-- Discussion containing changed information from previous version are highlighted. --
089
FXUS61 KPBZ 110549
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
149 AM EDT Tue Jun 11 2024

.SYNOPSIS...
Below average temperatures are expected through early Tuesday
under an upper-level troughing pattern. Rising temperatures and
dry weather will characterize the mid to late week period.
Thunderstorm chances may return Friday.

&&

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

- Clear conditions tonight will drop temperatures into mid-upper 40s
  with a lingering trough; pockets of fog may develop.

--------------------------------------------------------------

The shortwave over the region will begin to exit into the
overnight. The upper low will remain over the region for at
least another day. Showers associated with lift and daytime
heating have finally dissipated. The northwest flow will keep
clouds in place at least through the evening before beginning to
clear out overnight. Thus, the clearing clouds will allow for
radiational cooling. Probabilities range between 30% to 50% that
MinT`s will be less than or equal to 45F. Given the chance of
late clearing, lows may dip into the mid to upper 40s to around
50. Higher probabilities are noted in eastern Ohio where persist
clear conditions are likely. The areas in OH are the most likely
to experience fog but even here, where clearing is more certain,
the chances of 5 miles or below is only about 30%. Will leave
fog out for now as it will mostly be confined into the valleys.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:

- Cool conditions persist into Tuesday.
- Ridging early Wednesday morning returns near to above average
  temperatures across the region.

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Dry, quiet weather is expected Tuesday into Wednesday under
weak ridging. Temperatures will likely be near-average Tuesday
as cold air exits east. Wednesday, temperatures will trend above
the climatological average with sufficient warm advection from
the southwest. The passing trough well to the north along the
the northern Great Lakes significantly helps to lessen the
impact of the building ridge keeping temperatures through
Wednesday night at normal or just below.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
KEY MESSAGES:

- Warm, dry conditions are expected Thursday.
- Long range models are hinting that thunderstorm chances return
  Friday, there is a chance that a few storms could be
  considered strong to severe.
- Models have been consistent that hot conditions are favorable
  late week into early next week.

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With a ridging building to our south and elongated trough over
central Canada, zonal flow will advance warm conditions over the
Midwest into the region. Confidence is high that upper-80s
to near 90s will be observed at observation sites across the
region. Minus the heat index values in the low-90s for portions
of Ohio, no hazardous weather is expect Thursday.

Trough advancement out of the north will return the chance of
rain showers and thunderstorms Friday afternoon/evening. Several
runs of the long range models suggest convection may be
organized along the cold front. Probability of organized
convection (500J/kg and 30kts of effective shear) is 20% to
40% Friday evening with this noted disturbance.

Numerous long range models have been consistent that a ridge
axis will build across the CONUS and return warm, moist
conditions to the region. Heat impacts will need to be
monitored.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
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MVFR cloud deck is continuing to scatter into western
Pennsylvania overnight and bringing an end to CIG restrictions.
Clouds will linger longest north and east (FKL/DUJ/LBE) of PIT.
Given the building cool air mass, diminishing wind, and
relatively warm rivers, some patches of mainly valley-based fog
are possible and already appearing on satellite in areas that
have seen cloud cover dissipate. Latest hi res ensemble
probabilities favor a 50-60% chance of restrictions to MVFR VIS
for FKL and ZZV in the pre-dawn hours. Elsewhere where cloud
cover lingers, fog development shouldn`t be impactful.

Any fog should lift by 13z Tuesday morning, though probability
of MVFR CIGs at FKL/DUJ don`t indicate improvement until after
15-16z when flow backs to the west and cuts off the lake
moisture source. Scattered cumulus is expected during the late
morning/midday hours elsewhere. Northwest wind will generally
remain light at under 10 knots.

.Outlook...
VFR conditions are expected under building high pressure Tuesday
through Thursday. Restrictions in showers and thunderstorms return
Thursday night and Friday with another passing disturbance.
-- End Changed Discussion --

&&

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

&&

$$

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