356
FXUS61 KPBZ 090236
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1036 PM EDT Sat Jun 8 2024

.SYNOPSIS...
Light rain showers are possible along a passing cold front late
tonight into Sunday, with a low probability for additional 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.
- Sunday afternoon sunshine will help to maintain seasonable
  temperature.

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

10:30pm Update: No major changes have been made to this forecast
period. A swath of rain is currently positioned just of the
shore of northern Lake Erie and will likely reach our region
after midnight.

Previous Discussion:

Light rain showers ahead of the cold front will reach nwrn PA
near midnight and then advance sewd through Sun morning. Better
ascent/lift to the north is expected to result in greater
accumulation for nrn zones, while weaker moisture profiles/lift
limit coverage/intensity for ern OH zones. Average totals
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 sky (though some afternoon cumulus are likely to
develop) will support 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 a broad
ern-CONUS trough 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 /03Z SUNDAY THROUGH THURSDAY/...
A mid-level cloud deck can be seen invading the area from this
west this evening. This will gradually lower through the
evening, with MVFR cigs expected at most terminals by around
09z as scattered showers develop 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 (~50%) chance of that
occurring. Continued mention of locally lower cigs at those
terminals.

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.
Afternoon gusts of 15-20 kts are expected, diminishing after
sunset.

.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...Kramar/Frazier
NEAR TERM...Frazier/Hefferan
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...Cermak/Rackley