Winter Storm Watch 2, NWS Greenville-Spartanburg, SC

201 
WWUS42 KGSP 270746
WSWGSP

URGENT - WINTER WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
246 AM EST Wed Jan 27 2021

...ACCUMULATING SNOWFALL EXPECTED IN PARTS OF WESTERN NORTH
CAROLINA TONIGHT...

.An upper level disturbance will bring precipitation to much of
western North Carolina late Wednesday into early Thursday. An
accompanying cold front will permit temperatures to plummet across
the region tonight, with the precipitation changing over quickly
from rain to snow at the higher elevations of the North Carolina
mountains this evening before transitioning to snow in the valleys
through the night. The transition from rain to snow will occur 
more slowly out along the Interstate 40 corridor, but a few early 
morning snow showers will produce some light accumulations across
the northwest Piedmont as well, mainly east of I-77 across Davie 
County.

NCZ033-048>052-058-271700-
/O.UPG.KGSP.WS.A.0002.210128T0000Z-210128T1200Z/
/O.NEW.KGSP.WW.Y.0006.210127T2300Z-210128T1700Z/
/O.NEW.KGSP.WS.W.0002.210127T2300Z-210128T1700Z/
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Graham-
Including the cities of Ingalls, Banner Elk, Newland, Faust, 
Mars Hill, Marshall, Walnut, Allenstand, Hot Springs, Luck, 
Swiss, Burnsville, Celo, Micaville, Ramseytown, Busick, 
Spruce Pine, Poplar, Alarka, Almond, Bryson City, Luada, Wesser, 
Waynesville, Waterville, Canton, Cruso, Cove Creek, Robbinsville,
and Stecoah
246 AM EST Wed Jan 27 2021

...WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO NOON
EST THURSDAY ABOVE 3500 FEET...
...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
NOON EST THURSDAY BELOW 3500 FEET...

* WHAT...For the Winter Storm Warning, heavy snow expected. Total
  snow accumulations of 3 to 6 inches above 3500 feet in
  elevation. Winds gusting as high as 40 to 50 mph at times along
  the higher ridges. For the Winter Weather Advisory, snow
  expected. Total snow accumulations of 1 to 3 inches below 3500
  feet. Winds gusting as high as 40 mph at times.

* WHERE...The Tennessee border counties of the western North
  Carolina mountains.

* WHEN...From 6 PM this evening to noon EST Thursday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning commute on Thursday.

* ADDITIONAL DETAILS...Wind chill values near zero will be
  possible at the higher elevations by daybreak Thursday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for heavy snow means severe winter weather
conditions are expected or occurring. Significant amounts of snow
are forecast that will make travel dangerous. Only travel in an
emergency. If you must travel, keep a flashlight, food, and water
in your vehicle in case of an emergency. 

A Winter Weather Advisory for snow means that periods of snow
will cause primarily travel difficulties. Be prepared for snow
covered roads and limited visibilities, and use caution while
driving. 

Please report snow and ice accumulations by calling the National
Weather Service toll free at...1...800...2 6 7...8 1 0 1. Leave a
message with your observation and the specific location where it
occurred. You can also post your report to National Weather
Service Greenville Spartanburg Facebook or tweet your report
using hashtag nwsgsp. 

Stay tuned to NOAA Weather Radio or your favorite source of
weather information for the latest updates. Additional details
can be found at www.weather.gov/gsp. The latest state road
conditions can be obtained by calling 5 1 1.

&&

$$

NCZ037-271700-
/O.NEW.KGSP.WW.Y.0006.210128T0500Z-210128T1300Z/
Davie-
Including the cities of Farmington, Fork Church, Mocksville, 
and Advance
246 AM EST Wed Jan 27 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
8 AM EST THURSDAY...

* WHAT...Wet snow expected. Total snow accumulations of up to 
  one inch.

* WHERE...Davie County.

* WHEN...From midnight tonight to 8 AM EST Thursday.

* IMPACTS...Plan on slippery road conditions as temperatures dip
  below the freezing mark by daybreak. The hazardous conditions 
  could impact the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of snow
will cause primarily travel difficulties. Be prepared for snow
or ice covered roads and limited visibilities, and use caution 
while driving. 

Please report snow and ice accumulations by calling the National
Weather Service toll free at...1...800...2 6 7...8 1 0 1. Leave a
message with your observation and the specific location where it
occurred. You can also post your report to National Weather
Service Greenville Spartanburg Facebook or tweet your report
using hashtag nwsgsp. 

Stay tuned to NOAA Weather Radio or your favorite source of
weather information for the latest updates. Additional details
can be found at www.weather.gov/gsp. The latest state road
conditions can be obtained by calling 5 1 1.

&&

$$

HG

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
711 PM EST Tue Jan 26 2021

.SYNOPSIS...
Brief, dry high pressure returns through tonight before an area of
low pressure brings precipitation back on Wednesday into early
Thursday. Canadian high pressure will bring back dry conditions
Thursday afternoon through Saturday. A cold front will arrive from
the west on Sunday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 655 PM Tuesday: The low stratus deck scattered out across
much of the Upstate and all of the higher terrain hours ago, but
it has persisted over most of the NC Piedmont. In addition, visby
has crashed over the NC Piedmont during the past few hours and it's
looking like the fog will hang around for a while. Thus, we decided
to issue a Dense Fog Advisory that will be in effect until 4 am LT.
The latest guidance suggests that the fog could linger longer, yet
confidence remains low at this time.

Otherwise, later tonight a potent shortwave trough will eject east
across the Southern Plains, while a ridge axis shifts to the East
Coast. Profiles begin to moisten from the top down as the trof
approaches. (The thickening clouds may also help preclude dense
fog development elsewhere overnight). Mid-level frontogenesis will
set up across mainly the southern half of the forecast area, with
some upper-level divergence helping a rain shield to develop across
the area by daybreak Wednesday. PoPs will range from slight chance
north to likely south. Lows should be above normal, mainly in the
40s. On Wed, the area of frontogenesis will shift east by midday,
resulting in a relative lull in precip. However, moist low-levels
and lingering isent lift will support spotty light rain and lock
in low stratus across the area. Temps will likely only rise a few
degrees from morning lows, topping out mainly in the mid 50s. QPF
overall looks light. By late Wednesday, another round of strong mid
to upper forcing associated with an upper low tracking thru the Mid
South will result in a ramp up of PoPs toward the end of the day.
The highest chances look to be across the northern half of the area.
NLY CAA flow should also begin to ramp up by 00z Thursday, with temps
starting to fall along the TN border. A changeover to snow will start
on the highest peaks with some light accum before the end of the near
term. But the rest of the area should still be all rain.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 230 PM Tuesday: Height falls will be well underway by the
start of the short term, and precip should have begun several
hours prior.  By 00Z Thursday a deep 500mb trough will be centered
somewhere over TN and in conjunction with a powerful 250mb jet
streak stretching all the way east of the Appalachians will
provide ample forcing for deep tropospheric ascent.  By this
time, pre-frontal moisture will have shifted east of our CWA,
but a plume of moisture dropping south from the Ohio Valley will
set up ahead of the advancing trough, allowing for a second wave
of rainfall to sweep through the area.

Could see some snow accumulations owing to northwest flow cold
advection in the 1000-500mb layer.  Most will be in the mountains,
where upslope flow will drive increased precip; 850mb temperatures
could be -10 to -15 degrees C and 12z model soundings indicate good
saturation in the dendritic growth zone for several hours Wednesday
night.  A few flurries are possible outside the mountains, however,
as colder air filters into the foothills especially north of I-40.
By the wee hours of Thursday morning, a dry layer aloft will begin
pushing in, cutting off snow leading to a changeover to rain.
Seems unlikely most areas outside highest elevations will receive
more than an inch and a half of accumulation.  The biggest threat
is high winds Wednesday night.

Precipitation should let up between 06Z and 12Z Thursday when steep
height rises begin cutting off ascent and drier cT air filters in
from the west.  GFS model soundings show evidence of a growing dry
layer by 04Z or so, while the NAM holds off an extra couple hours.
Skies should clear out by Thursday afternoon, allowing temps to
climb on Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 230 PM EST Tuesday: Broad upper ridging will settle over the
central CONUS during the beginning portions of the extended. With
a sfc high settled across the East Coast, expect Saturday to
remain dry before changes take place on Sunday. Model guidance
eject a shortwave trough from the southwestern CONUS Friday night
through the High Plains and mid MS Valley by Saturday night as
the shortwave evolves into an upper low and cypresses the upper
ridge. Low pressure system riding underneath will develop over the
Southern Plains before going through cyclogenesis over the mid MS
Valley Saturday into Saturday night. The associated cold front
will encroach the area from the west with decent QPF response
ahead and along the boundary. The parent low will push into the
Midwest and OH Valley Sunday with good forcing to support precip
over our cwa starting overnight Saturday into Sunday morning as
a return flow enters the region. P-types are still questions as
the models diverge on the setup over our neck of the woods. The
Canadian and ECMWF have a classical CAD scenario with southerly
WAA flow at 850 mb. This would enhance the stable, cold air at the
surface and would allow for sleet/frzg rain to develop east of the
mountains if there is enough cold air pumped in from the N/NE. As
of now, wintry p-types should stay confined to the mountains, but
will be something to monitor through time. Otherwise, all liquid
will be in store for most locations at this time. As the fropa
occurs late Sunday, backside NW flow snow should develop along
the TN border and favorable upslope areas. The GFS has an all rain
scenario outside of the mountains and doesn't have the classical
CAD settling in like the other global models. Upper troughing and
lower thicknesses will linger over the area after the sfc cyclone
exits the region Monday. This will allow for temps to remain at
or slightly below normal through a good chunk of the medium range
as drier air filters in for the remainder of the forecast period.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Still expecting cig and visby restrictions
to continue thru much of the 00z taf period for most sites. The low
stratus deck scattered out across much of the Upstate and all of
the higher terrain hours ago, but has persisted over most of the
NC Piedmont. In addition, visby has crashed over our Piedmont sites
during the past few hours and it's looking like the fog will hang
around for a while. The latest guidance suggests that the fog will
linger thru early tomorrow morning and possibly a bit longer than
that. As confidence remains fairly low, I gradually bring the visby
back up VFR by late morning at KCLT and KHKY, but they could remain
down a bit longer. Otherwise, another system approaches from the west
and spreads mid and high clouds overnight. Sct showers are expected
to develop from SW to NE early tomorrow morning, spreading in across
the entire area after daybreak. The precip will likely lower cigs
and vsby back into the MVFR to IFR range between 12-18z. Winds are
generally calm or light and favoring a SWLY to WLY direction. They
will remain light and vrb thru much of tomorrow before picking back
up from the SW tomorrow evening. The only exception will be KAVL,
where winds will favor a NWLY direction thru most of the period.

Outlook: Moisture and precipitation are expected to spread across
the area thru Wednesday night. This will be followed by a return of
dry weather Thursday through Saturday.

Confidence Table...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       Med   61%     Med   71%     High  90%     Med   76%
KGSP       High 100%     High 100%     Med   72%     Med   77%
KAVL       High 100%     High  99%     High  95%     High  83%
KHKY       High  94%     High  97%     High  98%     Med   79%
KGMU       High 100%     High 100%     Med   69%     High  81%
KAND       High 100%     High 100%     Med   67%     Med   73%

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...Dense Fog Advisory until 4 AM EST Wednesday for NCZ035>037-056-
     057-068>072-082-501>510.
SC...Dense Fog Advisory until 4 AM EST Wednesday for SCZ008-009-014.

&&

SYNOPSIS...DEO
NEAR TERM...ARK/JPT
SHORT TERM...Rehnberg
LONG TERM...CAC
AVIATION...JPT

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
710 PM EST Tue Jan 26 2021

NCZ033-048>053-058-059-062>065-271200-
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
710 PM EST Tue Jan 26 2021

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

An upper level disturbance crossing the area late Wednesday will lead
to the development of coastal low pressure Wednesday night. Snow
showers will develop across the North Carolina mountains Wednesday
evening. Some accumulation is likely, with travel impacts likely at
high elevations. An advisory, watch or warning could be needed for a
portion of the mountains if confidence continues to increase. Very
windy conditions are also possible Wednesday night into Thursday.

.SPOTTER INFORMATION STATEMENT...

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

NCZ501-503-505-271200-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
710 PM EST Tue Jan 26 2021

...DENSE FOG ADVISORY IN EFFECT UNTIL 4 AM EST WEDNESDAY...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Tonight.

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

   Dense Fog Advisory.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

An upper level disturbance crossing the area late Wednesday will lead
to the development of coastal low pressure Wednesday night. Snow
showers will develop across the North Carolina mountains Wednesday
evening. Some accumulation is likely, with travel impacts likely at
high elevations. An advisory, watch or warning could be needed for a
portion of the mountains if confidence continues to increase. Very
windy conditions are also possible Wednesday night into Thursday.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-018-026-028-029-SCZ001>007-010>013-019-271200-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Oconee Mountains-
Pickens Mountains-Greenville Mountains-Greater Oconee-
Greater Pickens-Greater Greenville-Spartanburg-Anderson-Abbeville-
Laurens-Union SC-Greenwood-
710 PM EST Tue Jan 26 2021

This Hazardous Weather Outlook is for northeast Georgia and upstate
South Carolina.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ035>037-056-057-068>072-082-502-504-506>510-SCZ008-009-014-271200-
Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union NC-Greater Caldwell-Greater Burke-
Eastern McDowell-Rutherford Mountains-Greater Rutherford-
Polk Mountains-Eastern Polk-Cherokee-York-Chester-
710 PM EST Tue Jan 26 2021

...DENSE FOG ADVISORY IN EFFECT UNTIL 4 AM EST WEDNESDAY...

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

.DAY ONE...Tonight.

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

   Dense Fog Advisory.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Wimberley