166
FXUS61 KPBZ 142325
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
725 PM EDT Wed Aug 14 2024

.SYNOPSIS...
High pressure over Michigan tonight will move into New York and
Pennsylvania Thursday bringing quiet weather. Low pressure is
expected to cross the Great Lakes Friday and into southwest
Ontario on Saturday, pushing a cold front and showers and
thunderstorms across the Upper Ohio River valley.

&&

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

- Dry and comfortable weather continues with temperatures near
  normal.

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

With high over lower Michigan, northeast flow has prevailed
this afternoon with mixing to about 7,000 feet. Flat diurnal
cumulus field resulted but that will dissipate quickly late this
afternoon. Light winds and clear skies are expected tonight as
the surface high pushes into southwest Ontario and Pennsylvania
and an upper ridge pushes into Indiana and Michigan.

&&

.SHORT TERM /THURSDAY NIGHT/...
KEY MESSAGES:

- Dry weather with slowly rising temperature expected
  Thursday.


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

Weak surface high across PA/NY will gradually shift east as the
upper ridge moves across OH and reaches the PA border late
Thursday night. With heights building about 30 meters temperatures
should be a few degrees warmer and end up about 5 degrees above
normal on Thursday.

&&

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

- Shower/storms chances increases Friday, but timing issues
  still remain.
- The threat for rain continues into Saturday with slow passage
  of a cold front.
- Ensembles favor Great Lakes troughing into early next week
  that would maintain low probability, diurnally driven
  convection.
-------------------------------------------------------------------

Upper trough currently in the Dakotas is shown to amplify
Friday as is moves across northern Wisconsin and then heads for
lower Michigan Friday night. Weak height falls are expected over
forecast area Friday afternoon, with 40 meter falls at 500 mb
Friday night. SPC and CSU MLP have potential for severe
thunderstorms with wind damage seemingly slightly more likely
especially in Ohio Counties Friday night. NBM mean SBCAPE does
rise to about 1,000 j/kg and 500 mb flow of roughly 30 knots
suggest enough shear for multi-cell severe convection. PW of 1.5
to 2.0" suggests potential for heavy rainfall as well.

Heights continue to slowly fall Saturday and Saturday night as
the upper low heads into southwest Ontario. While severe storms
will remain possible across the area, it appears that the PA/WV
portions will have somewhat higher chances as 500 mb flow
increases to about 40 knots and NBM mean SBCAPE reaches 1,500+
j/kg. PW values will be a bit lower, closer to 1.5".

Upper trough crawls east across western and central PA on
Sunday, with shower chances continuing especially over PA/WV
counties.

Ensembles indicate that long wave trough will continue to linger
in the Great Lakes and Northeast States Monday, Tuesday, and
Wednesday. The standard deviation of 500 mb heights in this area
gradually increase with time as the details of short wave
troughs become less and less evident. NBM provides low rain
chances during the period with somewhat higher values on Monday,
but confidence is low and it certainly could end up being dry
for a few days with northwest flow.

&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
Light winds and clear skies are expected overnight into
Thursday under high pressure. Reduced VIS caused by fog may
drop FKL, DUJ, and LBE to MVFR between 08z-11z Thursday morning
before winds pick up. Low probabilities of IFR could be possible
for FKL. CIGs will lower after the end of the TAF period ahead
of a shortwave trough.

.Outlook...
VFR conditions are expected to continue into early Friday
morning before a shortwave brings chances of rain showers and
thunderstorms to the area. Probabilities of MVFR are around
10%-20% on Friday for all sites due to lowering VIS. An upper
level trough moves through on Saturday, causing showers and
occasional thunderstorms. MVFR (50%-70%) and IFR (30%-50%)
restrictions caused by low CIGs are more likely Saturday
morning, but could remain through the afternoon. Periodic
showers and thunderstorms with occasional restrictions are
possible through Monday with the slow moving trough.

&&

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

&&

$$

SYNOPSIS...Craven
NEAR TERM...Craven
SHORT TERM...Craven
LONG TERM...Craven
AVIATION...WM/Timmins