Penn Hills, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

645
FXUS61 KPBZ 031724
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1224 PM EST Tue Dec 3 2024

.SYNOPSIS...
Widespread snowfall is expected Wednesday evening into Friday,
with greater than six inches likely along and north of the I 80
corridor. Strong wind gusts are also expected Wednesday night
through Thursday; blowing snow along the ridges may reduce
visibility.

&&

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

- Lake-enhanced snow showers, primarily north of Pittsburgh,
  will diminish after 6pm.
- Below average temperatures continue.
-------------------------------------------------------------

A narrow band of light to moderate snow is currently tracking
north of I-80. Webcams confirm that brief periods of low
visibility and a coating on walkways are occurring. PA mesonets
currently have road temps a few degrees above freezing
(upper-30s) and will likely not impact travel.

Probability of snow bands associated with the lake will
decrease after 6pm as westerly flow increases low- level dry.
Additional accumulation through this evening will likely range
between 0.5 inches to 1.5 inches; higher amounts will likely be
focused in northern Venango and Forest county.

Breaks in clouds will increase temperatures above freezing in
some areas. Regardless of sfc heating, temperatures will
continue to trend below average by 10 to 15 degrees.

&&

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

- NEW: Blowing snow may create visibility issues in eastern
  Tucker; Winter Storm Watch issued
- Winter weather impacts increase late Wednesday into Thursday
  morning with strong cold front followed by lake
  effect/enhanced and terrain-forced snow showers Thursday
- Gusty winds (Advisory-level in the ridges) are expected with
  the front Wednesday night and Thursday
- Wind chill values will be below zero in the higher terrain
  early Friday morning

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

A deep trough will dig across the Upper Midwest and into the
Great Lakes region on Wednesday as a strong surface low crosses
Ontario. Warm advection into the afternoon will boost daily
highs into the mid/upper 30s (though still below average).

As low pressure passes to the north, a cold front will cross the
region Thursday evening into the overnight. Widespread snow
showers are expected by the late afternoon/evening hours,
diminishing early Thursday morning behind the cold front. Winds
will veer northwesterly behind frontal passage with strong cold
advection over the lakes Thursday into Friday. This will present
an optimal situation for heavy lake effect/enhanced snow along
the snow belt/I-80 corridor and terrain-forced upslope snow in
the ridges Thursday.

Between initial synoptic snow Wednesday night and heavy lake
effect through Thursday night, areas north of I-80 have a 50-60%
chance of 6" (Warning criteria) snow, with a 25-75th percentile
range of roughly 4 to 10 inches. Local snow totals in this area
will depend heavily on snow bands, with some locations likely
much closer to 10, and others much closer to 4 inches. In
collaboration with neighboring offices, have issued a Winter
Storm Watch for lake effect snow from Wednesday night through
early Friday morning.

Snowfall immediately south of I-80 and in the ridges, though
lesser than north of I-80, has a 70-85% chance of reaching 3+
inches. A Winter Weather Advisory will likely be needed for
these areas.

A second concern will be strong gradient wind. Gusty wind is
expected as early as Wednesday afternoon ahead of the cold
front and with a strong 50-60kt LLJ, peaking overnight into
Thursday behind the front. Lower terrain probabilities for
advisory level wind gusts (46+ mph) run at 25-50%, and the NBM
mean max gust is 40-45 mph nearly areawide. However, an advisory
is very likely in the ridges where probabilities are greater
than 75% and max gusts above 50 mph are expected. Eastern Tucker
County, WV in particular may need a High Wind Warning as
forecast gusts near 65-70 mph.

Strong wind gusts will further complicate travel in locations
with snowfall, causing snow drifts and reducing visibility.
Therefore, the Winter Storm Watch was expanded into eastern
Tucker county.

The Thursday morning commute may be particularly difficult
along the I-80 corridor and in the ridges, where snowfall and
wind will be maximized. Strong winds will also lead to low wind
chill values Thursday morning. The ridges will see single digits
wind chills, with higher peaks possibly dropping below zero.

&&

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

- Brief break later Friday before snow chances return for the
  weekend
-------------------------------------------------------------------

Snow showers are expected to taper off Friday and Friday night
as the trough exits and flow backs to the SW.

There is much higher uncertainty for the weekend, with high
pressure to our south. There is the possibility for another
wave to bring additional precipitation Saturday into Sunday,
but still little agreement on this. However, there is higher
confidence in a more robust system early next week. Regardless,
temperatures will remain below average through the period.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Lingering light snow showers can be seen on radar near the
PA/WV border. This acivity is expected to continue to wind down
and move out of the area shortly after sunrise.

The passage of the trough axis and low-level flow backing to SW
will allow for modest improvement of ceilings during the late
morning and afternoon hours Tuesday, with decreasing snow shower
activity. ZZV, MGW, and to some extent, HLG are most likely to
enjoy scattered cloud coverage during much of the day.

A W to WSW wind of up to 10 knots can be expected through the
period, with some gusts near 20kt on Tuesday.

Outlook...
Restriction and snow potential returns late Wednesday with a
warm front. Widespread restrictions, snow showers and gusty
winds are then expected Wednesday night and Thursday with a
cold front and subsequent upper troughing and lake enhancement.

Improvement to VFR is expected from S-N Friday as the wave exits
and wind backs to the SW. Restriction and snow potential returns
Saturday with a warm front.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Winter Storm Watch from Wednesday afternoon through late
     Thursday night for PAZ007>009-015-016.
OH...None.
WV...Winter Storm Watch from Wednesday evening through Thursday
     afternoon for WVZ514.

&&

$$

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