Winter Storm in Georgia, January 6 to 7, 2017

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
730 PM EST Fri Jan 6 2017

.SYNOPSIS...
A low pressure system will lift out of the Northern Gulf of Mexico
tonight bringing widespread winter precipitation to the region. As the
low moves offshore, a strong arctic surface high will overspread the
region late Saturday and persist into early next week, bringing very
cold air into the region. Another cold front is expected to approach
the Carolinas by the middle of next week, increasing rain chances
once again.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 8 PM, the brief lull in the precip is coming to an end, as
additional precip continues to fill in along an axis from eastern
Alabama through N Georgia and into western NC. This will overspread
the remainder of the forecast area through the next couple of hours.
Locations above about 1500', and roughly along and north of an axis
from Rutherfordton, to Lincolnton, to Salisbury in NC will be
solidly snow, while after an initial bout of rain and perhaps sleet,
a transition to snow is expected to occur down to near the I-85
corridor by midnight or so. South of there, considerable uncertainty
lingers regarding the timing of a transition, as wet bulb temps from
Anderson to Union to Chester SC are lingering near 40 degrees, and
there is not expected to be a tremendous push of cold surface air
into these areas over the next few hours. In fact we're beginning to
get concerned that those areas won't see any significant
near-surface cooling until the moisture begins to shift east of the
area. We will wait for the event to unfold a little more (and await
00Z guidance) before making any radical changes to the forecast and
products, but confidence that the warning will work out over the
southern half of the Upstate and northeast GA is beginning to slip.

Confidence is higher along the I-85 corridor, but considering the
warm nose indicated on special 18Z Raob from KFFC, and the fact that
sfc temps are going to need to drop another couple of degrees before
the transition to snow occurs, am concerned that initially rain,
followed perhaps by sleet, will cut into the snow accums in those
areas.

Meanwhile, forecast confidence remains high for locations
north of the I-85 corridor. Expect there will be some banding
overnight with frontogenetical forcing and slant-wise instability
developing, so locally higher amounts than the 4-8 inches forecast
in these areas will certainly be possible.

Precip will taper off quickly Saturday morning and end before noon
as the upper and surface systems move away from the area taking the
moisture and forcing with them. Should be breezy to windy during the
morning with winds tapering off by late afternoon. Will likely see
some sun as well. However, highs will likely be below freezing
across much of the area, with mid 30s developing along the Upper
Savannah River valley. This may just set the stage for black ice
where any snow can melt.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
At 2 PM Friday: On Saturday night an upper trough will extend from
Great Lakes to the Gulf of Mexico, while an upper ridge will be over
the Western USA. At that time, a significant shortwave will be
exiting the East Coast, while channeled vort lobes round the trough
along the Gulf Coast and the mid MS and lower OH River Valleys. The
trough progresses off the east coast on Sunday, while a modest vort
lobe crosses the mid MS River Valley and heads toward the Southern
Appalachians. This vort lobe crosses our area on Monday. By Tuesday
deamplification of the upper pattern will result in nearly zonal
flow across the CONUS, a pattern that persist until reamplification
of an eastern trough and western ridge occurs next Friday During
this time, the bulk of upper level vorticity will be channeled to
our north.

At the surface, on Saturday night dry high pressure will be moving
east across the MS River Valley in the wake of a departing cold
front off the East Coast. The surface ridge crosses the Southern
Appalachians on Sunday, reaching the Eastern Seaboard by Monday.
This ridge lingers over the Carolinas and Georgia into Tuesday,
while moisture increases in advance of a cold front crossing the
Great Plains. This front reaches the Southern Appalachians on
Friday, stalling over the area during the day. The front lifts north
of our area on Thursday, at which time the models disagree on moist
inflow form the Atlantic and Gulf in advance of another cold front.
This new front crosses the OH River Valley on Friday, but the model
diverge further on timing. Temperatures will start our well below
normal, warming to above normal late in the week.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM EST Friday: A flat upper ridge will be in place across
the southeast Monday night into early Tuesday, with a lingering nose
of coastal surface high pressure remaining across the western
Carolinas. Tuesday will be our first opportunity to see temperatures
appreciably rebound and promote some melting of lingering snow
cover, with maxes in the 40s throughout and perhaps near 50 in the
lower piedmont.

Heights will then fall again across the central plains later Tuesday
and upper jet divergence will sharpen up ahead of this feature
through Tuesday night. Southwesterly low level flow will increase
and the best combination of returning moisture and pre-frontal
upglide should arrive Tuesday night through Wednesday morning. There
remains a small potential for any earlier onset Tuesday morning to
produce spotty light freezing rain in lingering cold mountain valley
locations, but precipitation chances look much better late
Tuesday/Tuesday night after temperatures warm above freezing.

The approaching frontal zone will likely stall across the region on
Wednesday as zonal flow redevelops aloft. Deep layer southwest flow
should then gradually get reestablished Thursday through Friday
with Gulf and Atlantic moisture slowly getting tapped. With the
uncertainty, will keep late week shower PoPs at chance levels for
the mountains and slight chance east, with temps rising well above
climo.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
KCLT and Elsewhere: Brief lull in the precip will come to an end
over the next couple of hours, as the next round of precip
overspreads the terminal forecast area. The precip-type will be SN
at KAVL/KHKY, while other terminals should see precip begin as -RA
or a mix of RA/SN/PL, but all areas should see a transition to all
snow by midnight or so. A tempo for 1/2SM in snow has been included
at KAVL/KHKY, but with lingering uncertainty regarding the timing of
the transition at the other terminals, will only advertise tempo IFR
condition from 03-06Z. All terminals see categorical IFR visby/LIFR
cigs from 06Z through sunrise, although periods of 1 mile or less
will be possible, if not likely.

Snow will begin taper off in most locations by late Sat morning,
when cigs will also begin to lift. VFR conditions are expected by
mid-afternoon at most terminals. Winds will generally be from NE
through N at around 10 kts through the period.

Outlook: VFR conditions expected Sunday and Monday as an arctic high
moves across the region. A frontal system approaches Tuesday and
Wednesday with precip and associated restrictions possible.

Confidence Table...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       High  84%     Low   44%     Med   62%     High  96%
KGSP       Med   67%     Low   43%     Med   69%     High 100%
KAVL       High  87%     Med   73%     High  89%     High  99%
KHKY       Low   59%     Med   66%     Med   68%     High 100%
KGMU       Med   65%     Low   44%     Med   70%     High 100%
KAND       Low   55%     Low   55%     Med   71%     High  97%

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

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Winter Storm Warning until 1 PM EST Saturday for GAZ010-017-
     018-026-028-029.
NC...Winter Storm Warning until 1 PM EST Saturday for NCZ033-
     035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...Winter Storm Warning until 1 PM EST Saturday for SCZ001>014-
     019.

&&

SYNOPSIS...SBK
NEAR TERM...JDL/RWH
SHORT TERM...JAT
LONG TERM...HG
AVIATION...JDL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
301 PM EST FRI JAN 6 2017

NCZ033-048>053-058-059-072015-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-
301 PM EST FRI JAN 6 2017

...WINTER STORM WARNING IN EFFECT FROM 7 PM THIS EVENING TO 1 PM EST
SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON 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...SATURDAY THROUGH THURSDAY.

..SATURDAY...WINTER STORM LIKELY. PLEASE SEE THE LATEST CAEWSWGSP
FOR DETAILS.
..SUNDAY...DANGEROUS WIND CHILL POSSIBLE. AN ARCTIC AIR MASS WILL
BUILD INTO THE REGION...BRINGING EXCEPTIONALLY COLD TEMPERATURES.
GUSTY
WINDS COMBINED WITH THESE COLD TEMPERATURES WILL LEAD TO DANGEROUS
WIND
CHILLS OF 5 TO 15 BELOW ZERO...ESPECIALLY AT ELEVATIONS ABOVE
3500 FT.
..MONDAY...COLD WAVE POSSIBLE.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..WEDNESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGE TO REPORT SNOW AND ICE ACCUMULATIONS
TO THE NATIONAL WEATHER SERVICE.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-062>065-068>072-082-
501>510-SCZ001>014-019-072015-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-
DAVIE-CATAWBA-ROWAN-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-
GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-CHESTER-GREENWOOD-
301 PM EST FRI JAN 6 2017

...WINTER STORM WARNING IN EFFECT FROM 7 PM THIS EVENING TO 1 PM EST
SATURDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON 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...SATURDAY THROUGH THURSDAY.

..SATURDAY...WINTER STORM LIKELY. PLEASE SEE THE LATEST CAEWSWGSP
FOR DETAILS.
..SUNDAY...COLD WAVE POSSIBLE. AN ARCTIC AIR MASS WILL BUILD INTO
THE REGION...BRINGING EXCEPTIONALLY COLD TEMPERATURES.
..MONDAY...COLD WAVE POSSIBLE.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..WEDNESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGE TO REPORT SNOW AND ICE ACCUMULATIONS
TO THE NATIONAL WEATHER SERVICE.

07

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
547 PM EST FRI JAN 06 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0444 PM     SNOW             MARION                  35.68N  82.01W
01/06/2017  E0.1 INCH        MCDOWELL           NC   BROADCAST MEDIA

            SNOW COATING GROUND IN DOWNTOWN MARION WITH FLURRIES
            STILL

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
633 PM EST FRI JAN 06 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     SNOW             1 N SALUDA              35.24N  82.35W
01/06/2017  M1.3 INCH        POLK               NC   COCORAHS

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
744 PM EST FRI JAN 06 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 PM     SNOW             2 SE WOODFIN            35.62N  82.57W
01/06/2017  M0.5 INCH        BUNCOMBE           NC   TRAINED SPOTTER

            UNC ASHEVILLE

&&

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
842 PM EST FRI JAN 06 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0838 PM     SNOW             5 N SIX MILE            34.88N  82.82W
01/06/2017  E0.2 INCH        PICKENS            SC   AMATEUR RADIO

&&

LEV

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
853 PM EST FRI JAN 06 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0851 PM     SNOW             BLACK MOUNTAIN          35.61N  82.33W
01/06/2017  M1.5 INCH        BUNCOMBE           NC   TRAINED SPOTTER

&&

LEV

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
856 PM EST FRI JAN 06 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0849 PM     SNOW             MARION                  35.69N  82.01W
01/06/2017  M0.5 INCH        MCDOWELL           NC   BROADCAST MEDIA

            ROADWAYS COATED WITH SNOW AND BECOMING SLUSHY

&&

LEV