Heavy Snow in Georgia, February 6 to 7, 2021

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
114 PM EST Sat Feb 6 2021

.SYNOPSIS...
Low pressure will spread moisture north across our region through
tonight then move off the East Coast on Sunday. Dry high pressure
builds back into the area on Monday. Unsettled weather is
possible through the rest of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 100 PM: Cloud cover continues to spread over the area ahead
of the shortwave now near the ArkLaTex, and as the stalled frontal
boundary over the Deep South ripples northward. Sfc low eventually
will develop over the northern Gulf and then ride along the boundary
before tracking offshore tonight. Dewpoints remain low w.r.t. the
forecast, with even the new values entered last hour now proving
too high, reflecting the dry high pressure that will eventually
support in-situ CAD, developing after warm frontal precip spreads
in from the south later this aftn. Will have to take another look
at p-type this afternoon and evening as a result, but even with
good wet-bulbing temps are warm enough that precip probably will
start as rain everywhere except the higher mountains. 850mb temps
start out relatively cool through 06Z Sunday, but all model guidance
trended slightly warmer last night, and surges the freezing line as
far north and west as the eastern facing slopes of the Escarpment,
where a transition to sleet still is expected. This would ultimately
lower snow totals. That said, with more confidence on QPF timing,
have refined the fcst with hourly QPF increment, which allows us
to represent the hourly p-type changes more effectively in the
snow amounts. This raised the overall accumulations slightly in
the transition zone; not yet ready to adjust the placement of
hazards. Namely, for the aftn package, we will be reevaluating
p-type trends thru the event, and looking into whether any more
areas will have enough impact to be placed under Winter Wx Advisory.

So, keeping hazards as-is for now: Winter Storm Warning for
the mountains of all three states (as far south as Habersham GA)
starting this evening and going through Sunday morning, along with
a Winter Wx Advisory for the NC Foothills and NW Piedmont through
the same time frame as the warning. Warning-criteria conditions
reflect areas getting predominantly snow as opposed to sleet,
but also some QPF enhancement due to terrain.  The advisory area
will likely have more sleet/rain mix in and will ultimately lessen
overall "snow" totals (as official "snow" accum includes sleet).

Expect the heart of the moisture to arrive between sunset and
midnight as QPF amounts soar. Freezing rain is not expected as a
hybrid/in-situ CAD develops with the aforementioned sfc high that
lingers just off the mid-Atlantic coast during the event, but as
noted above the extent of rain/sleet/snow will change from hour
to hour, at least until temps settle into their wedgiest state,
so to speak. Most areas outside of the high country will make
at least a brief transition to wintry p-types along and north
of I-85. Elevations >4000' will likely receive 3-6+" in snow
accumulations, while 2-4" will be in store for the rest of the
mountains as the probability to mix with sleet increases. 1-3"
likely along the Escarpment and sheltered valleys, while little
to no accumulation expected farther east.

Expect min temps to run at or slightly above normal with clouds
and precip overhead Saturday night. PoPs begin to drop rapidly by
the very end of the period as the system quickly lifts off to the
north and east.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 145 AM EST Saturday: The low pressure system moves northeast
away from the area Sunday taking the moisture with it and bringing
the precip to an end by afternoon. There will be some light
additional NW flow snow along the TN border during the morning,
along with generally rain outside of the mountains before precip
ends. Despite the clearing skies and downslope northwesterly flow,
have gone toward the cold side of guidance for highs, around 10
degrees below normal across the mountains and around 5 degrees below
normal elsewhere.

Dry and seasonal high pressure builds in through Monday. Lows Sunday
night and highs Monday will be a little below normal.

A weak short wave moves through the developing zonal flow Monday
night. Guidance disagrees on the amount of moisture return and
developing isentropic lift. Have gone with a guidance blend which
keeps all but the far southern CWFA dry until near morning, and even
then only a slight chc PoP. With lows around 5 degrees above normal,
p-type would be rain.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 310 AM EST Saturday: Guidance in general agreement through the
medium range but with detail differences. A few weak short waves
move through the zonal flow early in the period. An upper low moves
into the northern Plains and a short wave rotates around this low
and across the area Friday. At the surface, high pressure builds in
from the northeast. Some moisture and isentropic lift moves in with
the weak short waves. There may be some light precip Tuesday and
Wednesday. Temps may be cold enough for some snow to mix in across
the mountains, but temps are expected to be above normal. Precip
chances ramp up Thursday as moisture increases ahead of a cold front
associated with the short wave rotating around the upper low. The
GFS is a little slower with this system moving the front across the
area during the day Friday. The ECMWF is a little faster. The GFS
has precip Friday while the ECMWF is dry. Either way, warmer temps
are expected as cold air has been delayed again with the slower
amplification of the pattern. Precip would be mostly rain, with even
some thunder possible across the southern CWFA. NW flow snow would
be possible as the front moves east.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Altostratus will thicken this afternoon, not
looking likely to lower into impactful low-VFR range until the first
bands of light precip spread in from SW to NE, starting in the late
afternoon. At KCLT, kept the low VFR in TEMPO until precip is likely
enough to prevail. Low pressure passing near the SE Coast overnight,
along with developing in-situ cold air damming, should result in
cigs crashing to LIFR at all sites by late evening. KAVL and KHKY
will see snow overtake rain as predominant p-type as temps drop
via evaporative cooling. Elsewhere, temps likely will hover just
above freezing, but some wintry mix remains possible at KGSP/KGMU
in the late evening, and KCLT overnight (likely between the end
of evening ops and before morning ops begin). Introduction of a
warm layer into the otherwise cold profiles aloft will mean PL more
likely than SN, when not purely RA. Departure of the low will turn
winds NW and downslope from early morning onward, with the shift
progressing NW to SE. This should erode the CAD, though not likely
until nearly the end of the period...except at KAVL. There, the
wx will turn to more of a NW flow event, allowing snow showers to
linger a bit longer, some hope for MVFR, and winds to become gusty.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     Med   66%     Low   56%     Med   75%
KGSP       High  99%     Low   59%     Med   65%     Med   70%
KAVL       High  98%     Med   65%     High  82%     Med   74%
KHKY       High 100%     Med   76%     High  81%     Med   70%
KGMU       High  97%     Low   59%     Med   69%     Med   72%
KAND       High  91%     Low   47%     Med   73%     Med   75%

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...Winter Storm Warning from 6 PM this evening to noon EST Sunday
     for GAZ010-017.
NC...Winter Storm Warning from 6 PM this evening to noon EST Sunday
     for NCZ033-048>053-058-059-062>065-501>507-509.
     Winter Weather Advisory from 6 PM this evening to noon EST
     Sunday for NCZ035>037-056-068-069-508-510.
SC...Winter Storm Warning from 6 PM this evening to noon EST Sunday
     for SCZ001>003.

&&

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

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
415 AM EST Sat Feb 6 2021

GAZ010-017-NCZ033-048>053-058-059-062>065-501>507-509-SCZ001>003-
070915-
Rabun-Habersham-Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-
Graham-Northern Jackson-Macon-Southern Jackson-Transylvania-
Henderson-Caldwell Mountains-Greater Caldwell-Burke Mountains-
Greater Burke-McDowell Mountains-Eastern McDowell-
Rutherford Mountains-Polk Mountains-Oconee Mountains-
Pickens Mountains-Greenville Mountains-
415 AM EST Sat Feb 6 2021

...WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO NOON EST
SUNDAY...

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

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

   Winter Storm Warning.

.SPOTTER INFORMATION STATEMENT...

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

NCZ035>037-056-068-069-508-510-070915-
Alexander-Iredell-Davie-Catawba-Cleveland-Lincoln-Greater Rutherford-
Eastern Polk-
415 AM EST Sat Feb 6 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO NOON
EST SUNDAY...

This Hazardous Weather Outlook is for piedmont North Carolina and
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.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

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

   Winter Weather Advisory.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ029-NCZ082-SCZ011>014-019-070915-
Elbert-Union NC-Abbeville-Laurens-Union SC-Chester-Greenwood-
415 AM EST Sat Feb 6 2021

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

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ018-026-028-NCZ057-070>072-SCZ004>010-070915-
Stephens-Franklin-Hart-Rowan-Gaston-Mecklenburg-Cabarrus-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-York-Anderson-
415 AM EST Sat Feb 6 2021

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

.DAY ONE...Today and tonight.

A period of a sleet and snow mix is possible tonight along and near
the Interstate 85 corridor. If the wintry mix lasts long enough, a
light accumulation is possible and may lead to slippery roads
overnight.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.