-- Discussion containing changed information from previous version are highlighted. --
889
FXUS61 KPBZ 120316
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1116 PM EDT Sat May 11 2024

.SYNOPSIS...
-- Changed Discussion --
Scattered rain showers likely through tonight with passage of a
cold front. Dry and more seasonable weather will develop
through Monday before the next round of upper level disturbances
increase precipitation chances midweek.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
KEY MESSAGES:

- Scattered showers remain overnight
-------------------------------------------------------------------

The thunderstorm and severe weather potential has ended with the
passage of a cold front. An upper low across southern Ontario
and the Lower Great Lakes region will drop southeastward
overnight. This should maintain scattered showers across the
region. Lows will be near average for this time of the year.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
KEY MESSAGES:

- Dry weather likely, saving for passing disturbances near far
  northwest PA.
- Above normal temperature likely by Monday.
-------------------------------------------------------------------

Shortwave ridging ahead of a deepening central CONUS upper
trough will promote dry weather and rising temperature through
Monday. Residual NW flow Sunday with the surface high just to
the west will limit the degree of temperature rebound. But as
heights further increase Monday and the surface high positions
along the eastern coast, warm advection in southwest flow will
drive temperature to about 5 degrees above the daily average.

Any precipitation chances during this period will be tied to
shortwave movement well to the north and the positioning of a
developing warm front near the region. Latest trends lift the
warm front and upper wave north of the region, but will
maintain low probability chances in northwest PA in case those
trends change.

&&

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

- Midweek showers and thunderstorms likely, with limited severe
  and flooding threats.
- Dry conditions likely to end the week.
-------------------------------------------------------------------

The sagging central plains trough will meander eastward across
the TN River Valley Tuesday into Wednesday, with weak shortwaves
likely traversing the Upper Ohio River Valley ahead of the wave.
Showers and thunderstorms are likely through the
afternoon/evening Tuesday, though positioning of forcing and
potential influence of shortwave ridging in the mid-Atlantic
could alter the areal coverage/probabilities. Early analysis
suggests that the instability/shear parameters are unlikely to
promote much severe threat, while forcing/deep moisture should
remain south of region and limit a flooding threat (only 20%
probability of seeing greater than 1" of rain over 24 hours at
any location).

The trough will progress towards the eastern coast Wednesday,
with low positioning and depth dictating how long precipitation
will linger in the Upper Ohio River Valley. Ensembles are
confident in ridging developing over the lower Ohio River
Valley late week that should promote a few day period of dry
weather and above normal temperature.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
General VFR conditions, except in the NW, into the overnight
hours. Shower activity will slowly dissipate overnight, but hang
on into the post-dawn morning in the NW. Cold advection late
tonight and Sunday morning should return MVFR to localized IFR
stratocu to most terminals before high pressure and subsidence
lift area cigs to VFR levels.

Will include fog at the generally prone ports. The most
impactful fog may be at ZZV as they will clear out later
tonight. LIFR fog is possible at ZZV with MVFR possible at other
ports.

.Outlook...
VFR favoring through Monday under the influence of high
pressure.  Slow progression of the next upper level trough
system means increases precipitation and restriction potential
Monday night through Wednesday night, peaking Tuesday night into
Wednesday.

&&

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

&&

$$

SYNOPSIS...Frazier
NEAR TERM...WM
SHORT TERM...Frazier
LONG TERM...Frazier
AVIATION...Frazier