377
FXUS61 KPBZ 071742
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
142 PM EDT Fri Jun 7 2024

.SYNOPSIS...
Probability of light precipitation will increase late this
morning north of Pittsburgh with passing shortwave. Below
average temperatures are also expected into late Saturday.

&&

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

- Probability of rain shower activity increases after day break
  north of Pittsburgh with a passing shortwave.
- Confidence is high that rainfall total amounts through Friday
  evening will be less than 0.25 inches.

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

Weak shortwave movement through the base of the closed Great
Lakes upper trough will provide enough lift to generate isolated
to scattered showers across northwest PA. 12z soundings
reinforce the idea of a staunch 700mb inversion that will cap
storm heights; though up to 500 J/kg CAPE may allow for storm
intensification, that cap will keep storm tops below most of the
ice layer (below -10 degrees C) and keep lightning and severe
weather limited.

A drier air mass to the south will help to maintain dry weather
as the wave passes. The main impact will be scattered to broken
afternoon cumulus as temperature settles a few degrees below the
daily average. High pressure and additional cool advection
within NW flow will support below average overnight temperature
but dry conditions.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
KEY MESSAGES:

- Dry weather with near normal temperature is expected Saturday.

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

Ridging to the west support a dry and quiet Saturday and the
return of near-normal temperature.

A shift from west to southwest flow will likely return warm,
moist conditions to the region Saturday night. However,
temperature will likely still range near the climatological
norm.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
KEY MESSAGES:

- A passing cold front will return rain chances to the region
  early Sunday.
- Cool temperatures to start should warm next week.
- Hot conditions may develop late week with a noted ridge in
  long range models.

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

Convection returns early Sunday morning as a low pressure ejects
out of the Plains and quickly passes into the Ohio River
Valley. A few stray showers may evolve ahead a cold front, but
Hi-Res model suggest shower activity confided to the boundary.

In the wake of the cold front, expected clouds clearing and
temperatures recovering to near just slightly below average.

A strong ridge out of the Dakotas will continue to stream cool,
northerly flow into the region Monday into Tuesday. If the sky
remains cloud free, temperatures have the chance (NBM suggesting 40%
to 60%) to fall below 50 degrees north of Pittsburgh and along
the ridges.

Precipitation chances remain low (less than 30%) Monday through
Wednesday given long range uncertainty of a developing
disturbance.

Long range models are suggesting a pattern shift (June 13th-
June 15th) as a ridge axis builds and returns warm conditions to
the region. The NBM 50th percentile is suggesting hot
conditions Thursday into Friday as temperatures range in the
upper-80s to low-90s.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As expected, a broken cu field with VFR cigs has developed
across the entire area thanks to convective temperatures being
reached via daytime heating/mixing. Isolated to scattered
showers have also continued generally along and north of I-80,
with only minor impacts primarily limited to FKL/DUJ. Westerly
winds have become breezy and are sustained at 10-15 knots with
frequent gusts up to 25 knots being observed at most terminals
as of the 17Z obs. Expect these ongoing conditions to continue
through the remainder of the afternoon, though the coverage of
showers north of I-80 should gradually taper as drier boundary
layer air begins to make its way into the area limiting
moisture and instability. The cu field dissipates and winds
settle after sunset with the loss of daytime heating and mixing.

Light winds and VFR conditions then prevail overnight into
Saturday as weak high pressure briefly builds into the area.
Winds could start gusting 15-20 knots again with the onset of
daytime heating/mixing after 15Z Saturday, but overall winds
should be weaker and gusts less frequent than today.

.Outlook...
Scattered showers and associated restrictions return Saturday
night through Monday as another disturbance moves through the
Great Lakes region. High pressure brings widespread VFR back to
the area Tuesday.

&&

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

&&

$$

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