-- Discussion containing changed information from previous version are highlighted. --
867
FXUS61 KPBZ 071250
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
850 AM 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/...
-- Changed Discussion --
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.
-- End Changed Discussion --


&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
Mid level clouds are evident in early morning visible satellite
imagery and surface obs north of PIT/BVI, rotating around an
upper low centered over Ontario and the Great Lakes. Model
soundings and the CU rule indicate a scattered to broken diurnal
cumulus layer with VFR cigs will develop by mid to late morning
(roughly after 15Z) as convective temperatures are reached, and
continue through the day.

A few showers are beginning to form over northeast Ohio per
latest radar imagery. This trend is expected to continue and
expand eastward throughout the day, with showers expected
mainly north of PIT in closer proximity to the upper low and in
an area with more favorable moisture. An isolated thunderstorm
also cannot be ruled out primarily around FKL/DUJ this afternoon,
though chances remain too low for inclusion in the TAF at this
time. Any heavier showers or thunderstorms that form could bring
brief periods of locally lower cigs/vis to impacted terminals.

A sufficiently tight pressure gradient and mixing will combine
to produce breezy conditions late this morning through the
afternoon, with west winds gusting as high as 25kt. Clouds
should gradually decrease this evening as temperatures fall
below convective thresholds. Wind will also diminish with
decreased mixing. Mostly clear skies and light winds prevail
thereafter overnight.

.Outlook...
VFR conditions prevail during the day Saturday, followed by
increasing potential for periodic restrictions and scattered
showers Saturday night through Monday as another disturbance
moves through the Great Lakes region. Prevailing VFR should
return Tuesday under high pressure.

&&

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

&&

$$

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