962
FXUS61 KPBZ 270514
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
114 AM EDT Sat Apr 27 2024

.SYNOPSIS...
Showers will move through the region this morning with a
crossing warm front. A rumble of thunder is possible as well.
Warm temperatures today and Sunday. An afternoon shower or storm
is possible across the north on Sunday.

&&

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

- Showers with a low chance of storms persist through the
  morning, departing to the east by afternoon.
- Warmer temperatures today.

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

A warm front, trailing an eastward moving ridge axis, will cross
the western half of the region by dawn. The front will spark
scattered showers as it moves eastward. A lack of upper level
support will keep the shower activity light. NBM probs of >0.10
inches is 20 to 40%, with the higher values across northern
portions of western PA. Warm advection overnight will prevent
temperatures from falling off very much and they may actually
rise before the showers begin.

Upper level ridge axis will be pushed eastward this morning as a
weak shortwave trough slides across Ohio. In between the trough
and ridge, a surface warm front will cross the region, exiting
to the north by early afternoon. Showers will move through this
morning and should clear the northeast by early this afternoon.
A rumble of thunder is possible at any time this morning, but
forecast soundings continue to show little to no instability and
a low-level inversion. Rainfall amounts should be light. NBM
probs for >0.10 inches are generally 20 to 40%.

Once the showers clear, strong warm air advection is expected
this afternoon. Highs today, even with lingering cloud cover,
should be 5 to 10 degrees above normal. The warmest temperatures
will be across the west, with the coolest over the northeast.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
KEY MESSAGES:


- Summer-like temperatures Sunday and Monday.
- Storms Sunday are possible north of I-80.

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

Rising 500mb heights are expected again on Sunday as a large
dome of high pressure builds over the eastern CONUS. A weak
shortwave will try and sneak over top of the ridge Sunday
afternoon. This will stall the ridge amplification and could
spark a shower or storm mainly over the I-80 corridor. This
upper level wave will likely bring an increase in clouds across
the northern half of W PA as well, while the rest of the
forecast area should see plenty of sun. A destabilization of
the atmosphere is possible Sunday afternoon with the greatest
across the north. Storm generation will be working against warm
air aloft and increased subsidence from the impressive ridge.
The ridge will also work to limit wind shear on Sunday,
hampering storm intensification.

The big story Sunday will be the well above normal temperatures.
Highs Sunday will push into the 80s across much of the region,
except the far north where cloud cover should keep temperatures
a bit cooler.

Upper level ridging will continue on Monday. The ridge will
shift southeastward Monday afternoon as a deep trough digs into
the western Great Lakes. However, strong subsidence from the
ridge should allow for a dry day with plenty of sunshine and
even warmer temperatures.

&&

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

- An unsettled pattern continues through next week with above-
  average temperatures favored.

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

A surface cold front is expected to pass during the day on
Tuesday, followed by a flattening of the eastern ridge. By
Wednesday, clusters still vaguely agree on quasi-zonal flow, but
uncertainty spurs from here into late week. Mainly, two
scenarios emerge: the first develops a central CONUS ridge that
enforces an eastern troughing pattern. This would lead to a
drier, cooler pattern. The second scenario keeps quasi-zonal
flow in the central CONUS, which translates to zonal flow to the
east as well. This pattern may lean a bit warmer and more
unsettled.

Both CIPS analogs and the CSU MLP highlight low severe
probabilities into Tuesday through Thursday, so conditions will
need to be monitored as we head into next week.

&&

.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
Mainly VFR conditions are expected this morning as a warm front
lifts northeastward across the Upper Ohio Valley region. A band
of showers is expected to develop along the front, as an upper
ridge flattens across the region. Low VFR cigs are expected in
the showers for most airports, though FKL and DUJ will likely
see MVFR with better low level moisture expected. A period of
IFR is also expected at DUJ.

Expect rising cig heights after the passage of the warm front,
expect for DUJ, where MVFR should continue into tonight as the
warm front stalls and low level moisture pools along it. SE wind
around 10 kt should veer to the south after FROPA, with speeds
continuing around 10kt.

.Outlook...
Mainly VFR is expected Sunday through Monday as a ridge builds
back across the region. An isolated afternoon thunderstorm is
possible for FKL/DUJ Sunday as a weak disturbance moves across
southern Ontario on the northern periphery of the ridge.

Restrictions are likely Tuesday in showers and a few
thunderstorms with a crossing cold front. VFR returns Wednesday
under high pressure.


&&

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

&&

$$

SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22
LONG TERM...Milcarek
AVIATION...WM