Heavy Snow in North Carolina, February 1 to 2, 2021

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
241 PM EST Mon Feb 1 2021

.SYNOPSIS...
A cold and deep upper level disturbance will linger over our region
through Tuesday producing significant amounts of snow in the
mountains near the Tennessee border.  This disturbance will slowly
move out to the east on Wednesday as dry and somewhat warmer weather
is expected midweek.  Expect a strong cold front to arrive this
weekend bringing a return to colder temperatures.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 200 PM Monday: The upper low embedded with the trough has set
up shop over the cwa, with the axis of the trough centered over the
Carolinas. This has allowed for snow enhancement across the high
elevations with deep moisture and fairly potent upper forcing. The
synoptic scale enhancement has allowed for some of this activity to
slither outside of the mountains where rain/snow showers have
persisted through the morning hours and will continue into the
afternoon, mainly as rain with a few flakes or ice pellets mixing
in. As the upper low moves off to the east, expect precip outside of
the mountains to shut off, with mid- to upper-level clouds hovering
above. The NW flow snow will then become more of a pure upslope
event. The orographic lift will be featured across the TN border and
Smokies where over a foot of snow is still possible between now and
by the end of the period. Most of the higher amounts associated with
this event will be above ~3500-4000', where thermal profiles
indicate favorable for snow with heavy snowfall rates. Most of the
activity should linger through the morning hours on Tuesday before
gradually shutting off by the afternoon/evening, with drier air
filtering in. The Winter Weather Advisory is still in effect for
elevations below 3500', but those in populated areas along the TN
border and down the valley away from the TN border, snow amounts
lessen by a lot in these areas compared to the higher peaks. Expect
a general 1-3" in these locations, while areas under the warning
will exceed 4+".

Surface winds will continue to uptick through the rest of today and
into the overnight hours as high-res models indicate winds of up to
40-50 kts at the 850 mb level and a very tight pressure gradient
along the spine of the high country. With this prolonged wind event,
a Wind Advisory has been issued starting at 7 pm tonight through 1
PM Tuesday for Henderson and Buncombe Counties and along the Blue
Ridge Escarpment. The advisory-level gusts will likely continue
through the end of the near term before eventually subsiding as we
go into the short term forecast. Wind issues will also be
acknowledged in all of the winter weather products as well.
Temperatures will run below normal for max temps today and Tuesday,
while min temps remain above normal due to continuous cloud cover
and gusty winds.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 115 PM Monday: One last short wave rotates around the upper
low over New England and across our area Tuesday night. Lingering
low level moisture and NW flow over the mountains will combine with
the wave for one last hurrah for isolated snow showers near the TN
border. Very windy conditions will linger across the mountains as
well. Mostly clear skies and breezy conditions expected elsewhere.
Lows will be 5 to 10 degrees below normal with low wind chill values
across the higher elevations.

An upper ridge builds into the area Wednesday and Thursday as the
upper low and associated trough move slowly east. Surface high
pressure moves over Wednesday then off shore Thursday as
southwesterly flow develops between the departing high and a cold
front moving into the MS valley. Winds will slowly diminish through
the day Wednesday. Expect an increase in clouds Thursday but precip
remains to the west during the day. Lows Wednesday night will still
be around 5 degrees below normal. Highs will begin to warm Wednesday
in the moderating air mass, with highs reaching near normal levels
for Thursday. ions Tuesday night and Wednesday morning. Things
finally settle down Wednesday afternoon with sfc ridge reaching the
area, with relatively quiet weather Wednesday night. Temps will
remain at least two categories below normal thru the period, but
will start to trend back up Wednesday.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 225 PM Monday: Guidance seems to be trending in the same
direction for the medium range; however, there are still some
significant detail differences that would affect sensible weather
for the weekend. A relatively strong northern stream short wave
phases with a weak southern stream wave which move across the area
Friday. A series of strong short waves dive into the central CONUS
from Canada carving out a deep upper trough over the eastern half of
the CONUS by Sunday with a strong upper low over the Great Lakes.
Strong height rises occur Monday as the trough moves east and zonal
flow sets up in its wake.

The Canadian, which favored the ECMWF yesterday, now favors the GFS.
The guidance all agrees that a cold front associated with the
initial waves crosses the area Friday. This system is relatively
warm with mainly rain for all but the higher elevations. The GFS
then pushes the front well south of the area Saturday with a clipper
type system crossing the area Saturday night with the second series
of waves bringing in a very cold air mass behind it. The ECMWF is
slower with the frontal movement. It then develops a more of a
hybrid Miller A/B type system Saturday night and Sunday with the
second series of waves. It also ushers in a very cold air mass
behind this system. Although both systems would bring some of the
coldest air in years, the GFS would suggest snow mainly for the
mountains. The ECMWF would suggest wintry precip across much of the
area Saturday night and Sunday. With better agreement on the initial
system, have likely to high chance PoP with the front Thursday night
and Friday. Low chance to slight chance PoP with the second system
given the differences.

Temps look to be above normal Thursday night and Friday. Temps begin
to drop Friday night and Saturday, but only slowly until Sunday
night and Monday when the crash to well below normal levels in the
arctic air mall. Just how low they go remains to be seen.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: W/NW will persist through much of the TAF
period with VFR cigs/vsbys, with the exception of KAVL, which will
be in and out of MVFR/VFR conditions through the period. Snow
showers from the mountains will become enhanced enough to bring
flakes into KAVL with little to no accumulation. Showers have
started to push out of the Upstate sites and KHKY, but precip still
surrounds KCLT and should begin to taper off over the next couple of
hours. VFR cigs/vsbys will be in store through the rest of the
period, which makes this more of a wind forecast, especially at KAVL
where gusts have already picked up. Gusty winds are introduced at
all TAF sites during the day tomorrow as winds are still expected to
come out of the W/NW. The forecast will remain dry through the TAF
period and for much of the work week.

Outlook: Precip chances and restrictions probably will remain
confined to the mountains west of KAVL Tue, so the TAF sites likely
will be VFR during this time. The next chance of precip and
restrictions will be Friday with the next frontal system.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High  94%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High  88%     High  87%     Med   76%     High 100%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High 100%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Wind Advisory from 7 PM this evening to 1 PM EST Tuesday for
     NCZ053-065-501-503-505-507-509.
     Winter Weather Advisory below 3500 feet until 1 PM EST Tuesday
     for NCZ033-049>052-058.
     Winter Storm Warning above 3500 feet until 1 PM EST Tuesday
     for NCZ033-049>052-058.
     Winter Weather Advisory above 3500 feet until 1 PM EST Tuesday
     for NCZ053.
     Winter Storm Warning until 1 PM EST Tuesday for NCZ048.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...CAC
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...CAC

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
407 AM EST Mon Feb 1 2021

GAZ018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-506-508-
510-SCZ001>014-019-020915-
Stephens-Franklin-Hart-Elbert-Alexander-Iredell-Davie-Catawba-Rowan-
Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union NC-
Greater Caldwell-Greater Burke-Eastern McDowell-Greater Rutherford-
Eastern Polk-Oconee Mountains-Pickens Mountains-Greenville Mountains-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-York-Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
407 AM EST Mon Feb 1 2021

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-049>052-058-020915-
Avery-Yancey-Mitchell-Swain-Haywood-Graham-
407 AM EST Mon Feb 1 2021

...WINTER STORM WARNING IN EFFECT UNTIL 1 PM EST TUESDAY ABOVE
3500 FEET...
...WINTER WEATHER ADVISORY IN EFFECT UNTIL 1 PM EST TUESDAY BELOW
3500 FEET...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Winter Weather Advisory.
   Winter Storm Warning.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Winter Weather Advisory.
   Winter Storm Warning.

Additionally, bitterly cold wind chills may develop in some locations
Wednesday morning, particularly at high elevations.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to report snow and ice accumulations to our
office.

NCZ053-020915-
Buncombe-
407 AM EST Mon Feb 1 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 1 PM EST TUESDAY ABOVE
3500 FEET...
...WIND ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO 1 PM EST
TUESDAY...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Winter Weather Advisory.
   Wind Advisory.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Winter Weather Advisory.
   Wind Advisory.

Additionally, bitterly cold wind chills may develop in some locations
Wednesday morning, particularly at high elevations.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ048-020915-
Madison-
407 AM EST Mon Feb 1 2021

...WINTER STORM WARNING IN EFFECT UNTIL 1 PM EST TUESDAY...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Winter Storm Warning.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Winter Storm Warning.

Additionally, bitterly cold wind chills may develop in some locations
Wednesday morning, particularly at high elevations.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to report snow and ice accumulations to our
office.

NCZ065-501-503-505-507-509-020915-
Henderson-Caldwell Mountains-Burke Mountains-McDowell Mountains-
Rutherford Mountains-Polk Mountains-
407 AM EST Mon Feb 1 2021

...WIND ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO 1 PM EST
TUESDAY...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-NCZ059-062>064-020915-
Rabun-Habersham-Northern Jackson-Macon-Southern Jackson-Transylvania-
407 AM EST Mon Feb 1 2021

This Hazardous Weather Outlook is for northeast Georgia and western
North Carolina.

.DAY ONE...Today and tonight.

Blustery winds will develop today in the wake of a cold front.
Occasional gusts of 25 to 35 mph may occur at higher elevations,
which could continue through tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Winds will continue to be brisk and gusty through Tuesday, beginning
to taper off Tuesday night.

.SPOTTER INFORMATION STATEMENT...

None.

Wimberley