606
FXUS61 KPBZ 081744
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
144 PM EDT Sat Jun 8 2024

.SYNOPSIS...
Light rain showers are possible along a passing cold front late
tonight into Sunday, with additional low probability showers on
Monday. Temperature will fall to near 10 degrees below average
by Monday before returning to above normal temperature by
Wednesday.

&&

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

- Cold front will create a broken line of light rain showers
  tonight into Sunday morning.
- Enough sunshine Sunday afternoon will help to maintain
  seasonable temperature.

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

Gradual moist advection resulting in increased cloud cover is
expected through this evening as an upper level shortwave and
associated surface cold front approach from the Great Lakes.

Light rain showers ahead of the cold front will reach northwest
PA near midnight and then advance southeast through Sunday
morning. Better ascent/lift to the north is expected to result
in greater accumulations for northern zones, while weaker
moisture profiles/lift limit coverage/intensity for eastern OH
zones. Average total locations should be less than 0.10" with
only a 20% probability of exceeding 0.25" north of I-80.

Dry advection and subsidence will quickly erode precipitation
chances behind the cold front, resulting in dry weather after
9am. Clearing skies (though some afternoon cumulus will develop)
will allow for enough insolation to maintain seasonable
temperature.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
KEY MESSAGES:

- Additional shortwave movement and a cold front will drop area
  temperature below seasonal averages.

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

Weak embedded vortices rounding the western edge of the trough
axis may provide enough lift with lake moisture enhancement to
generate an isolated rain shower late Sunday into Monday
morning. A more notable wave movement will push a reinforcing
cold front southward through the day Monday, creating low
probability light rain showers as column moisture remains
limited. More notably, cooler air behind that front and an
uptick in daytime cloud coverage will cause area temperature to
fall 5 to 10 degrees below the daily average.

High pressure and subsidence are favored for Monday night,
promoting clearing skies and more efficient radiational cooling.
Expect area low temperature to be 10 degrees below the daily
average, with a low probability for pre-dawn river valley fog
formation.

&&

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

- Height rises and high pressure will support dry weather and
  rising temperature through Thursday.
- Uncertainty remains in potential late week pattern shift.

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

Ensemble models continue to favor gradual height rises over the
Upper Ohio River Valley Tuesday through Thursday while surface
high pressure generally is anchored along the Atlantic Coast.
There is a high probability for this to be an extended stretch
of dry weather while temperature rises to above normal levels by
Thursday.

More uncertainty arises in the synoptic evolution of a potential
upper level wave attempting to move southeast out of Alberta.
The most likely scenario sees this wave traversing just north
of the region late Thursday into Friday with increases
shower/thunderstorm chances ahead of the surface boundary. There
remains a low probability that this wave lifts farther north,
limiting precipitation chances and allowing for higher Friday
temperatures. This potential trough movement is likely to be
short-lived, with ridging favored in its wake over the lower
Ohio River Valley by the start of next weekend.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A scattered cu field with VFR cigs has developed primarily north
and east of PIT this afternoon, with only some scattered to
broken high clouds elsewhere. Meanwhile, west-southwest winds
have generally remained around 7-10 knots with infrequent gusts
to 15-20 knots. These conditions prevail through the remainder
of this afternoon. An overcast mid level cloud deck is observed
on visible satellite imagery just upstream over western Ohio
and southeast Michigan moving eastward towards the local area.
These will make their way into our area around 00Z, followed by
a gradual lowering trend in cigs to MVFR at most terminals
(highest chances north of I-70) by 06Z as scattered showers
develop along and ahead of an approaching cold front. Hi-res
ensemble guidance continues to suggest potential IFR cigs at
FKL/DUJ for a few hours in the 09Z-12Z timeframe, with the
latest run maintaining a medium (~60%) chance of that occurring.
Thus, included mention of locally lower cigs at those terminals
compared to others in the area.

Showers depart to the east with the passage of the cold front
Sunday morning around 12-15Z. Clouds scatter back out to VFR
and winds shift to northwesterly in the wake of the front.

.Outlook...
VFR prevails Sunday afternoon in the wake of the cold front
passage. Additional restrictions and scattered showers are
expected again late Sunday night and Monday with another
crossing upper trough. VFR follows on Tuesday and Wednesday
under building high pressure.

&&

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

&&

$$

SYNOPSIS...Frazier
NEAR TERM...Frazier
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...Cermak