939
FXUS61 KPBZ 231217
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
717 AM EST Sat Nov 23 2024

.SYNOPSIS...
Rain, and snow across the higher elevations, will gradually
taper off today as low pressure exits the region. Dry weather
returns Sunday under high pressure, before rain chances increase
Monday and Monday night with a crossing cold front. An unsettled
weather pattern then returns from mid to late week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Rain (and snow in the higher terrain) tapers off today
------------------------------------------------------------------

Update...
Cancelled the Blizzard Warning for eastern Tucker county as
rates and winds have lessened as low pressure exits east.

Previous discussion...
A mid and upper level low was centered off of the NJ coast this
morning. A vorticity maximum will continue to rotate around the
low across the Upper Ohio Valley region this morning,
maintaining a band of rain. Snow is expected in the higher
elevations, mainly across eastern Tucker county WV. Even in
these areas, warm advection has in less efficient snowfall
rates. This diminishing trend in the snow and wind should
continue this morning, as moisture in the dendritic growth
region also diminishes.

Areas that were in the Winter Storm Warning have warmed above
freezing, with much of the precipitation now in the form of
rain. Cancelled the warning early due to this. Continued the
Blizzard Warning for Tucker county with still some additional
snow and gusty wind expected early this morning.

The ascent/vorticity maximum will track eastward today as the
mid and upper low exits the coast. Precipitation is expected to
taper off from west to east as this occurs. Patchy drizzle/light
rain will still be possible with low level moisture in place,
though most of the precip will be exiting to the east.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
KEY MESSAGES:

- Patchy light rain possible tonight in warm advection
- Dry Sunday
- Rain returns Monday and Monday night with a cold front
-------------------------------------------------------------------

Warm advection will begin tonight. Overrunning should result in
low chances for light rain overnight, though no significant QPF
is expected.

High pressure will build across the Ohio Valley region on
Sunday, resulting in a gradual clearing trend and dry weather.
Continued flat upper ridging, ahead of a Central CONUS trough,
will maintain the dry weather Sunday night. The digging trough
will track eastward early in the week, as a surface low develops
in response across the Midwest. This low will track across the
Great Lakes/Ontario region by late Monday, pulling a cold front
across the area.

Rain chances will increase through the day as the front
approaches, and jet enhanced ascent occurs. This rain will
continue Monday night as the front completes its passage.
Rainfall amounts are expected to range from a quarter to a half
of an inch.

&&

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

- Rain/snow chances Tuesday with an upper trough
- Mainly dry Wednesday
- Rain/snow chances return by late week
-------------------------------------------------------------------

The lingering upper trough, and cold NW flow, will result in
rain and snow chances mainly north of PIT on Tuesday, before the
trough exits. Surface high pressure under broad troughing aloft
should maintain dry weather and cooler than average
temperatures on Wednesday.

Model ensembles indicate a trough will advance out of the Plains
region Wednesday, as a surface low develops across the TN
Valley region. Increasing moisture and ascent in southwest flow
ahead of the trough, and on the northern side of the developing
surface low, will return rain and snow chances to the region
Wednesday night and Thursday. Operational models differ on the
positioning of the surface low, and the northern extent of any
precipitation. Stayed close to the ensemble blends for the
Thanksgiving forecast, with uncertainty in the details.

Rain and snow become more likely Thursday night and Friday as
the initial trough crosses the region, and another approaches
from the northwest. Overall, temperatures will average below
seasonable levels through the period.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Light rain continues for terminals east of ZZV and west of DUJ
as a low pressure system slow advances east off the Atlantic
Coast. IFR to MVFR ceilings are expected through 12Z as northwest
flow provides sufficient low-level moisture off the Great
Lakes.

Organized precipitation will weaken and gradually advance east
as ridging builds to our west after 12Z. Region-wide MVFR
throughout the remainder of the TAF period remains high
confidence.

Outlook...
VFR cigs should return early Sunday as high pressure builds.

Restriction chances return later Monday and into Tuesday as a
cold front crosses the region.

&&

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

&&

$$

SYNOPSIS...WM
NEAR TERM...WM/88
SHORT TERM...WM
LONG TERM...WM
AVIATION...Hefferan/Rackley/AK