-- Discussion containing changed information from previous version are highlighted. --
351
FXUS61 KPBZ 111747
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
147 PM EDT Tue Jun 11 2024

.SYNOPSIS...
Continued dry weather and a warming trend is expected through
Thursday. Thunderstorms return for the day on Friday. There is
medium to high confidence in a heat wave next week that may
bring moderate to major heat-related impacts.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:

- Cool and dry weather continues today with patchy fog
  overnight.

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On the backside of an upper low, north-northwest flow will allow
temperatures to remain a few ticks below seasonable normals
today and tonight. A passing shortwave axis circumventing the
low may allow the maintenance of a broken to scattered cumulus
to stratocumulus deck through this evening with weak cold
advection enforcing saturation near the top of the mixed layer.

Tonight, the loss of mixing and eastward progression of the low
will allow cumulus coverage to decrease at the expense of some
patchy cirrus overnight as upper moisture streams overhead.
Despite this, high pressure will allow calm winds and efficient
cooling, allowing for patchy valley fog. Fog is most likely east
of the Pittsburgh metro and valleys.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
KEY MESSAGES:

- Dry and near-to-above normal temperatures prevail through
  Thursday evening.
- A rumble of thunder is possible overnight Thursday.

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Dry and quiet weather is expected with upper ridging on
Wednesday. Light to calm west winds and rising heights will keep
Wednesday highs around five degrees above normal, and diurnal
trends will allow lows to cool near seasonable normals. Patchy
valley fog cannot be ruled out Wednesday night.

Thursday, the high will move east and a disturbance will pass to
the north, allowing for a light southwest winds and a further
push of daytime highs around ten degrees above normal. An
approaching disturbance overnight will result in increasing
cloud cover or perhaps a rumble of thunder by late Thursday
night along and ahead of a passing cold front. CSU MLP hints at
severe potential, but with overnight profiles, the threat should
remain mostly elevated before daybreak save any stronger
storms. Mid- level dry air suggests that hail and winds will be
the primary threat, by low probability through 8am Thursday.

&&

.LONG TERM /FRIDAY 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 strong to
  severe.
- Models have been consistent that hotter conditions are
  favorable late week into early next week.

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

The better chance for showers and storms will occur along the
cold front itself as it pushes through the area during the day
Friday. Probability of organized convection (500 J/kg and 30kts
of effective shear) is 20% to 40% Friday evening with this noted
disturbance, meaning there is some low-end potential for a few
storms to become strong or severe.

Long range guidance has been consistent that a ridge axis will
build across much of the central and eastern CONUS thereafter
through the weekend and into the following week, bringing warm
and humid conditions to the area. There is a growing concern
that significant heat will be possible, especially as we get
into early next week, with NBM probabilities for high temps
reaching 95+ degrees on Monday continuing to run around 50% or
greater. The highest probabilities for impactful heat are noted
across eastern OH and the valleys and low elevations of western
PA, including urban centers like Pittsburgh where the heat
island effect typically leads to locally warmer temperatures
compared to surrounding areas. There are some areas that are
currently forecast to reach heat indices of 100F by Monday
afternoon. If this trend in guidance continues, heat impacts
will need to be closely monitored and headlines may need to be
considered.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Northwest flow will continue through the day and into the late
afternoon. Expect afternoon cumulus development to continue and
with additional moisture in the north, FKL has maintained some
MVFR cigs even into the evening. Northwest winds will mainly
remain light through the evening and overnight. A few gusts up
to 15 knots at times can`t be ruled out. Drier air will begin to
infiltrate the region tonight with clearing skies expected. Some
isolated fog development is possible tonight but is not expected
to be widespread and mainly confined into the valleys. Cloud
cover overnight will only entail passing cirrus overhead.
Heading into the day tomorrow, VFR conditions persist after fog
dissipation between 14Z and 16Z.

.Outlook...
VFR conditions are expected under building high pressure
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...Milcarek
NEAR TERM...Milcarek
SHORT TERM...Milcarek
LONG TERM...Cermak/Milcarek
AVIATION...Shallenberger