813
FXUS61 KPBZ 161439
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1039 AM EDT Thu May 16 2024

.SYNOPSIS...
Dry conditions and seasonable temperatures expected today as
high pressure transitions across the region. Periodic showers
and a few afternoon storms are then expected through the
weekend.

&&

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

- Dry conditions, relatively light wind, and temperatures around
  5 degrees above normal.
  _____________________________________________________________

Update at 10:30 AM focused on generally minor updates to sky and
hourly temp/dewpoint grids. Low stratus will continue to burn
off over the next couple of hours, leaving a scattered/broken
cumulus deck. Low-chance terrain-induced afternoon showers are
still on the table.

Previous discussion...

Patchy morning fog and lower stratus is expected to improve this
morning with the onset of diurnal heating and influence of
surface high pressure. The rest of the day will be characterized
by generally dry weather, a mix of scattered to broken cumulus,
and temperature rising to around 5 degrees above normal as
an upper level ridge passes.

The other item of note is a slight increase potential for low
probability showers and thunderstorms this afternoon along the
higher terrain. Hi-res models suggest there may be enough
destabilization with heating plus weak terrain convergence to
promote the necessary lift under the ridge axis for such
development. Again, most locations are likely to remain dry but
areas along the Laurel Highlands and WV high terrain can`t rule
out a brief afternoon, non-severe storm.

&&

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

- Near to above normal temperature will continue.
- Shower chances return Friday.
  ______________________________________________________________

A weak trough is progged to push across Michigan and SW Ontario
on Friday, giving a glancing blow to the forecast area.
Instability is marginal but may be enough for a few
thunderstorms, primarily west of PGH as the airmass will be
moist, with MUCAPE of 1,000 to 1,500 j/kg.

&&

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

- An upper trough will maintain unsettled weather through the
  weekend.

- Ridging should result in dry weather Monday and Tuesday with
  shower chances increasing by Wednesday
- Temperatures near or above normal are expected
  ______________________________________________________________

Another weak upper trough, much like observed earlier in the
week will move slowly up the Ohio Valley on Saturday with
continued chances of showers and thunderstorms. Trends have been
for this system to head farther south toward VA/NC on Sunday,
which would result in less chance of showers for forecast area
Sunday. Will leave shower chances in Sunday, but if trends
continue it may end up drier Sunday than forecast.


Upper low then appears to get trapped along the NC coast, with
SW-NE ridging extending into Upper Ohio River Valley with warm
and dry conditions likely Monday and Tuesday.

Multi-model guidance then brings a fairly significant trough
through the Great Lakes and Ohio Valley by midweek, which would
likely result in showers and thunderstorms.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Morning stratus and localized fog will dissipate/lift with
increased diurnal mixing through 15z. Residual boundary layer
moisture and heating should then transition morning stratus to
sct/bkn low VFR cu that is expected to continue to lift and
scatter under the influence of high pressure. Any convection
that develops is likely to be isolated and favoring the higher
terrain east of KPIT. Avoided mention at this time but
monitoring localized areas of convergence that can aid storm
development will be key.

VFR is likely during the overnight period ahead of the next low
pressure system.

.Outlook...
Showers and isolated thunderstorms are likely Friday with
passage of a low pressure system. Continued influence of the
upper trough will maintain periodic shower and restriction
chances through Saturday before drier weather develops to start
the next work week.

&&

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

&&

$$

SYNOPSIS...88
NEAR TERM...CL/88
SHORT TERM...88
LONG TERM...Craven/88
AVIATION...Frazier