Fairmont, West Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

382
FXUS61 KPBZ 310538
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1238 AM EST Tue Dec 31 2024

.SYNOPSIS...
Weak high pressure will bring quiet weather tonight. Low
pressure currently over Missouri will move up the Ohio River
valley on Tuesday bringing rain. Colder air in the wake of this
low will change the precipitation to snow later Tuesday night
and Wednesday with significant accumulations especially north
of I-80 and over the ridges. Colder weather is then expected to
take hold through early next week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
KEY MESSAGES:

- A brief break in the active weather tonight.
--------------------------------------------------------------------

Only minor changes to the forecast for tonight, including
reducing sky cover north of Pittsburgh, as lower clouds have
already pulled off to the northeast. Only minor changes to
temp/dewpoint curves otherwise.

Previous discussion...

Weak high pressure will move over Ohio and Pennsylvania tonight
bringing quiet weather. Certainly some risk for valley fog but a
rapid return of mid to high clouds after midnight should limit
that risk somewhat.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
KEY MESSAGES:

- Period of rain Tuesday/Tuesday night with another low pressure
  system
- Snow showers expected Wednesday/Wednesday night, with the
  ridges most favored for accumulation.
- Winter storm watch issued for the West Virginia Ridges
--------------------------------------------------------------------

Low pressure organizing in Missouri currently should be in
Indiana by Tuesday morning. The parent low should track toward
Erie PA by evening and start to weaken as secondary cyclogenesis
takes shape over Maryland area Tuesday night with another low
heading for southern New England.

Decent warm advection rains should spread across the area later
Tuesday morning and Tuesday afternoon as a 120 meter height fall
center moves along the PA/WV border.

Cold advection starts to really kick in later Tuesday night with
850 mb temperatures starting out above freezing and then
crashing to about -6C by Wednesday morning, with continued cold
advection taking them closer to -10C by evening. With west to
WNW flow this will set up a Lake Effect event mainly north of
the forecast area but brushing the northern portion of the I-80
counties with perhaps 2-3" of snow. The ridges will also get
2-4" of snow with 4-8" over eastern Preston and Tucker Counties
in WV. That along with 50 mph wind gusts has prompted a winter
storm watch for WV ridges for late Tuesday night into Wednesday
night. CIPS analogs show 80%+ probability of 6" in this pattern,
and guidance is gradually ramping up the amounts.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
KEY MESSAGES:

- Late week pattern shift will favor below normal temperature,
  periodic snow, and high terrain gusty wind.
--------------------------------------------------------------------

All the teleconnections point toward sustained cold through the
middle of January. MJO is in phase 7 and moving into phase 8,
which is a cold signal for our area. GEFS show PNA heading more
positive, while blocking near Greenland and high heights has the
NAO going negative and suggesting west coast ridge and east
coast trough. AO showing a very negative trend towards a mean of
-4. So the dreaded pattern of being well below normal in the coldest
 part of the year after two mild winters will make this feel
 relatively bad.

Another trough expected with roughly 100 meter height falls
around Friday, which helps drop 850 mb temps from -12C range
toward -16C. Given the flow turns more NW, expect another round
of lake effect snow showers over more of the forecast area.

Saturday looks to be the coldest day this week with temperatures
likely to be about 10F below normal.

Uncertainty then increases substantially for Sunday and Monday.
Timing and details of what looks to be a potent trough
somewhere from the southern Plains to the Great Lakes area will
obviously lead to a snow or ice event that could be significant.
Because there is a wide spread of temperatures and QPF it is
hard to know yet how much impacts there will be in the Upper
Ohio River Valley.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR is expected through Tuesday morning, though mid and high
level clouds will increase ahead of approaching low pressure.
The low will pull a warm front north across the region early
Tuesday afternoon, with a band of rain and deterioration to
MVFR. Local IFR is possible in heavier rain.

MVFR and scattered to numerous showers are expected after the
passage of the warm front, with a thunderstorm also possible
with limited instability. Uncertainty in thunderstorm
development precludes a TAF mention. Further deterioration to
IFR is expected Tuesday evening as the low tracks across OH and
NW PA, and pulls a cold front across the region.

SE wind will increase Tuesday morning, with a few gusts up to 20
kt possible. Higher gusts are expected at LBE, where downsloping
wind will accelerate. Expect a WSHFT to the W after FROPA, with
gusts around 20kt.

Outlook...
Restrictions are likely Tuesday night and Wednesday as rain
changes to snow. Lake and terrain enhanced snow showers could
result in restrictions Wednesday night and Thursday. Snow and
more widespread restrictions are likely Friday with a crossing
cold front, and Saturday under cold NW flow off of the Great
Lakes.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...Winter Storm Watch from late tonight through late Wednesday
     night for WVZ512>514.

&&

$$

SYNOPSIS...Craven
NEAR TERM...Craven/CL
SHORT TERM...Craven
LONG TERM...Craven
AVIATION...WM