195
FXUS61 KPBZ 090458
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1258 AM EDT Sun Jun 9 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 TODAY/...
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 /TONIGHT 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 /06Z SUNDAY THROUGH THURSDAY/...
VFR is expected to deteriorate to MVFR cigs through early this
morning as a cold front tracks across the Upper Ohio Valley
region. A band of showers is also expected along the front,
though visibility restrictions should be localized with mainly
light rain for most airports.

A wind shift to the NW is expected after FROPA around sunrise,
with MVFR cigs continuing. Wind will become gusty with mixing
and a tighenint pressure gradient behind the front, with gusts
up to 20kt. Wind will diminish this evening with the loss of
mixing.

Clouds should scatter out into a cumulus/stratocumulus layer by
mid morning as surface ridging briefly builds in, with VFR
returning. Mainly mid level clouds cigs will return by evening,
ahead of an approaching reinforcing cold front.

.Outlook...
Additional restrictions and scattered showers are expected
again late Sunday night and Monday with another crossing upper
trough and reinforcing surface cold front. VFR returns Tuesday
through Thursday under high pressure.

&&

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

&&

$$

SYNOPSIS...Kramar/Frazier
NEAR TERM...Hefferan/Frazier
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...WM