376
FXUS61 KPBZ 301841
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
241 PM EDT Tue Apr 30 2024

.SYNOPSIS...
Apart from rain chances early tonight, the rest of the week will
remain dry and warm. A slight cool down is expected this weekend
with returning rain potential.

&&

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

- Rain chances diminish tonight with above average lows.

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Despite anomalously high PWATs, rain has been overall light
through much of the day with isolated convective elements in
areas east of Pittsburgh with longer period of sunlight. Even
then, convection is quite shallow; storms are not utilizing the
profile`s full potential. Additionally, shower/storm training
remains limited as the cold front progresses through. Combined
with weak shear and fumes of instability, both excessive
rainfall and severe concerns remain limited to none through
early overnight tonight.

Through the rest of tonight, skies are expected to clear from
the west, but lows will remain above normal with little
relaxation in dew points. As temperatures cool to near-
saturation, patchy fog is possible, particularly for river
valleys.


&&

.SHORT TERM /WEDNESDAY/...
KEY MESSAGES:

- Dry weather and above-normal temperatures expected Wednesday.

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Height rises and a return to southwest flow is expected on
Wednesday as temperatures push back into the 80s for most
locations. Clear skies and mixing into day air has led to a
slight upward adjustment in temperatures and downward
nudge in dew points. Nonetheless, fire weather concerns remain
low with light winds and humidity just above thresholds.

A weak front may move in later in the day into eastern Ohio,
but any convection will struggle in dry air. Dry conditions are
favored to continue. Dew points may recover slightly ahead of
the passage.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
KEY MESSAGES:

- Warm and dry weather expected under high pressure on Thursday.
- An unsettled pattern returns Friday through the weekend with
  above-average temperatures and periods of showers and
  thunderstorms favored.

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High pressure will continue to support above-normal temps and
dry conditions through Thursday night. Ensemble guidance
indicates the best chance for Thursday afternoon highs to exceed
80 degrees occurs south of I-80 where widespread probabilities
are 70% or greater. Lower probabilities (<50%) exist along and
north of I-80, where temperatures are more likely to top out in
the upper 70s. Lows Thursday night similarly range from upper
50s south of I-80 to low 50s farther north.

Ensembles continue to favor upper level trough movement through
the Great Lakes region Friday into the weekend that would push
the ridge axis southeast and lead to a return of more active
weather. While this more active pattern certainly increases
chances for showers and thunderstorms, it also introduces
greater uncertainty and makes it more difficult to narrow down
details regarding exact timing and intensity. According to the
latest ensemble runs, Saturday appears to be the most likely day
for widespread rainfall, though chances really begin to ramp up
Friday afternoon and could linger straight through the weekend
and into next week. Stay tuned for more on this as we get closer
to the weekend.

As for temperatures, at this time Friday appears to be the
warmest day of the period with highs potentially reaching the
mid to upper 80s across much of the area. In fact, ensembles
already indicate a 70% or greater chance of areas south of I-80
exceeding 85 degrees. Temperatures Saturday through Monday also
trend above normal, but could remain in the 70s due to thicker
cloud cover and a greater coverage of showers and thunderstorms.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A line of showers pushing east ahead of a weakening cold front
will continue to run into dry air and subsidence in western PA.
Daytime heating and some clearing was present on the central PA
side. Thus, this region will see the bulk of the thunderstorm
development. It is likely that only DUJ and LBE have the best
chance for development. Otherwise, isolated MVFR conditions will
be in place at the terminals through some of the evening. Some
IFR conditions may develop tonight.

Wind will shift to the northwest with frontal passage overnight
tonight as high pressure quickly builds. There is low to
moderate 30-50% confidence for areas of fog toward sunrise
Wednesday with ensemble probabilities maximizing primarily south
of PIT. This is conditional on whether or not wind remains
elevated overnight and likely focused on areas that receive the
most rain if any.

.Outlook...
VFR will return on Wednesday and Thursday under high pressure.

&&

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

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek
SHORT TERM...Milcarek
LONG TERM...Milcarek/Cermak
AVIATION...Shallenberger