152
FXUS61 KPBZ 050919
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
419 AM EST Wed Feb 5 2025

.SYNOPSIS...
A chance of light snow is possible this afternoon before a
wintry mix affects the region Wednesday night. The mix will
change to rain Thursday before ending. Dry weather returns
Friday under high pressure.

&&

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

- Dry weather expected through dawn.
- Light snow chances return this afternoon.
----------------------------------------------------------------

Mid level clouds will increase through the predawn hours ahead
of the next approaching shortwave trough. Lows are expected to
be near seasonable levels. This morning should be mainly dry as
the surface high slides east of the area. A band of light snow
is possible along an initial area of warm advection by mid
morning into the afternoon.

A shortwave trough will advance out of the Midwest Wednesday as
a surface low approaches the Ohio Valley. Precipitation is
expected to overspread the region but this will be more into
this evening and into tonight as the front approaches.

&&

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

- Wintry mix/freezing rain likely Wednesday night into Thursday
- Ice Storm Warning for the ridges Wednesday night through
  Thursday morning
- Winter Weather Advisory Wednesday night through early Thursday
  morning
--------------------------------------------------------------------

The onset of the precip over the entire region tonight should
be in the form of rain generally south of I 70 outside of the
higher terrain. To the north, dry air in place should result in
some evaporative cooling at the onset of the precip. This could
result in a decrease in temperature and freezing rain. Most ice
accumulation should be light (a glaze to a tenth of an inch,)
with one to two tenths along and north of Rt 422. The main
impact will be hazardous travel on untreated roads. In fact,
with the exception of some continues south of I-70, the rest of
the forecast area was placed in a Winter Weather Advisory to
address the short period of freezing rain before changing to all
rain.

With E-SE upslope flow across the higher terrain of the Laurel
Highlands, temperatures should remain at or below freezing
resulting in a prolonged period of freezing rain. Ice
accumulation of around a quarter of an inch is expected. Issued
an Ice Storm Warning for these areas, where the weight of the
ice could result in downed power lines and more significant
travel impacts. In addition, rainfall amounts could be high
enough to cause elevated river and stream levels especially
across the higher terrain areas of WV.

Strong warm advection and a wind shift to the south late
Wednesday night and Thursday morning should result in surface
temperatures rising above freezing, changing all of the precip
to rain before ending as the upper trough axis shifts east. As
the surface low tracks across the lower Great Lakes, a cold
front will cross the region Thursday afternoon, with only
minimal rain chances. It certainly is possible to see FZRA
lasting a tad longer in Forest County with a change over by 18Z.
Generally dry weather is expected Thursday night as high
pressure begins to build across the region.

&&

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

- Dry Friday
- Another low pressure system bring a potential wintry mix
  Saturday
- Generally dry Sunday and Monday
-------------------------------------------------------------------

Model ensembles indicate a broad trough across the central-
eastern CONUS through the period. Friday should be dry as
surface high pressure tracks across the region. A shortwave
embedded in the broad trough should return a wintry mix
potential to the region Saturday, depending on the exact track
of an associated surface low across the Upper Ohio Valley
region. Rainfall amounts will need to be monitored especially
for areas across WV. Surface high pressure returns generally
dry weather again Sunday and Monday.

Precip chances return Tuesday as a southern stream low moves
across the MS/TN valley region. The upper Ohio Valley region
will be on the northern area of this low, with POPs kept in the
chance range for now.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
Confidence remains low in the southern extent of an MVFR
stratocu deck early this morning. Recent model trends appear to
keep this farther north than previously anticipated, impacting
mainly FKL/DUJ. However, brief periods of MVFR may be possible
farther south early this morning. For now, have removed MVFR
mention south of I-80.

Restrictions are expected from the south after 00z Thursday
with rain and a wintry mix. Lingering sub-freezing surface
temperatures will allow a period of freezing rain for most
terminals overnight except MGW, with probabilities for more
than a light glaze highest at FKL/DUJ. A transition to all rain
will occur from south to north late Wednesday night into
Thursday, with restrictions continuing.


Outlook...
There is a low probability for thunder (less than 30%) along
and south of I-70 during the day Thursday. VFR returns Friday
under high pressure.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from 7 PM this evening to 4 AM EST
     Thursday for PAZ013-020-021-029-073.
     Winter Weather Advisory from 7 PM this evening to 10 AM EST
     Thursday for PAZ007>009-014>016-022-077.
     Ice Storm Warning from 7 PM this evening to 10 AM EST Thursday
     for PAZ074-076-078.
OH...Winter Weather Advisory from 7 PM this evening to 4 AM EST
     Thursday for OHZ039>041-048>050-057>059.
WV...Winter Weather Advisory from 7 PM this evening to 4 AM EST
     Thursday for WVZ001>003.
     Ice Storm Warning from 7 PM this evening to 10 AM EST Thursday
     for WVZ512-514.

&&

$$

SYNOPSIS...Shallenberger
NEAR TERM...Shallenberger
SHORT TERM...WM/Shallenberger
LONG TERM...WM/Shallenberger
AVIATION...Rackley