Alert archive / North Carolina / Wind Chill Advisories in 2017

Wind Chill Advisory 1, NWS Greenville-Spartanburg, SC

January 7, 201721 counties in North Carolina; Habersham County, Rabun County, Georgia

NWS Greenville-Spartanburg, SC issued this wind chill advisory at Jan 7, 2017, 3:42 AM EST for 21 counties in North Carolina; Habersham County, Rabun County, Georgia. It took effect at Jan 7, 2017, 7:00 PM EST. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued
Jan 7, 2017, 3:42 AM EST (08:42 UTC)
In effect from
Jan 7, 2017, 7:00 PM EST
Expired
Jan 8, 2017, 12:00 PM EST
In force
17 hr
Issued by
NWS Greenville-Spartanburg, SC
All 23 counties

Habersham County, GA, Rabun County, GA, Alexander County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Davie County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Iredell County, NC, Jackson County, NC, Lincoln County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Polk County, NC, Rowan County, NC, Rutherford County, NC, Swain County, NC, Transylvania County, NC

The radar

The Greer radar (KGSP), 67 km from the middle of the area, began a volume at 08:41 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 8.7 hours before the alert went out and 219 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 00:00Z on 2017-01-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 00:00Z on 2017-01-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
614 m above ground
0-6 km bulk shear
105 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
523 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this wind chill advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this wind chill advisory went out at Jan 7, 3:31 AM EST, 11 minutes earlier.

Area forecast discussion, Jan 7, 3:31 AM EST, 11 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
331 AM EST Sat Jan 7 2017

.SYNOPSIS...
A wintry low pressure system will move offshore today, as a strong
arctic surface high overspreads the region. The high will persist
over the area into early next week, keeping very cold air in place,
until the high slides east on Tuesday. Another cold front is
expected to approach the Carolinas by the middle of next week,
increasing rain chances once again.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM EST Saturday: Guessing that probably half of the
residents across the area are happy with us right now, and the other
half not so happy. As usual, the rain/snow line has been hovering
along and just south of I-85 through the early morning hours, and as
was the concern last night, cold air has lagged the moisture across
southern and southeastern zones with mainly just a cold rain
observed. All is not lost however because the cold air IS coming
(wetbulb zero line has made a little faster progress to the SE over
the past couple of hours) and there's still some precip out there.
06z KGSO sounding was fully below freezing everywhere but soundings
out of NCSU indicated more of a warm nose than was forecast (the NAM
had the closest and of course that was NOT the model of choice last
night. Typical...), and so we've seen a little more sleet southeast
of I-85 which has really complicated accumulations. Averaging the
zones it ended up verifying pretty well but for example knowing that
there's snow on the north side of Charlotte is little comfort to
kiddos on the south side. However, the event isn't over yet! Still
seeing some light bands across TN and GA, and hi-res models still
want to develop some banding in the deformation axis later this
morning (that if perfect-progged would stretch from the foothills to
the Upper Savannah Valley and then push east with the exiting
surface low). Between that and the low-level CAA, will leave the
warning in place but will re-word some of the southern to emphasize
the black ice more where we probably won't end up with accumulations
actually meeting technical warning criteria (though in all fairness
some of the sleet accumulations might actually reach the 1/2"
criteria).

The other concern is that as we start getting some drying aloft,
unless there's enough omega to pull moisture up to the dendritic
snow growth zone (which would be the case in a deformation axis),
then we lose the ice crystals aloft and end up with supercooled
liquid so we could see some light freezing rain or freezing drizzle.
Again, these are details that are really hard to convey in the grids
so just putting it out there.

Otherwise for today we have some bust potential in highs because
most guidance was expecting a little more snow on the southern end
of the forecast area and if that doesn't pan out, temps might warm
up a little more than expected today. Nevertheless strong CAA behind
the front will keep temperatures well below normal especially across
the mountains. Add to it the increasing pressure gradient as the
surface low strengthens off the coast and with temperatures dropping
into the lower teens and single digits in the mountains, it'll just
be downright brutal tonight in the mountains.  With that, have
issued a Wind Chill Advisory starting 00z for all the mountains
(criteria -5C), and a Wind Chill Warning for Yancey Mitchell and
Avery (criteria -15C). Still above record lows for the climate
locations but within a handful of degrees so will have to reevaluate
closely with this afternoon's package.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM Saturday...The Short Term will remain quite cold, with
little rebound in temps, as the center of arctic high pressure
slides in from Ohio Valley and settles right over central NC by 12z
Monday. Very cold low-level thicknesses along with a snowpack for
most of the CWFA along and north of I-85 will result in bitterly
cold min temps and highs staying below freezing. Most of the Upstate
and NE GA will see some mid to upper 30s both Sunday and Monday.
Even with the sub-freezing temps in the mountains and NC piedmont,
there should be a fair amount of sunshine which will melt snow/ice
off roads. Though, refreezing at night will likely result in black
ice issues Sunday night and possibly again Monday night. Min temps
will be in the single digits to upper teens Sunday night and mid
teens to mid 20s Monday night.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 315 AM Saturday...Temperatures will rebound nicely on Tuesday,
as the modifying arctic high exits off the East Coast. Meanwhile, a
cold front will approach from the west, but gets hung up across the
Carolinas, as flow aloft remains quasi-zonal. The atmosphere will
gradually moisten up ahead of the front Tuesday, with mentionable
PoPs creeping into the western zones by Tuesday evening.
Fortunately, temps should warm such that any precip that falls will
be just rain. Temps should warm into the 40s to around 50 throughout
on Tuesday, then cool into the mid 30s to around 40 Tuesday under
increasing clouds and precip.

Wednesday thru the end of the week, an upper trough will dig across
the western CONUS, while a downstream ridge amplifies along the East
Coast in response. So the stalled frontal boundary will lift north
as a warm front by Thursday ushering in mild high pressure into the
region. The best chance for rain with the lingering frontal boundary
will be Tuesday night into early Wednesday, with chance to likely
PoPs. Then PoPs ramp down to mainly slight chance for Thursday and
Friday, with the next frontal system still well west of the area.
Temps will warm to well above normal, with highs in the mid 60s by
Friday in the lower elevations.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and Elsewhere: -SN just about everywhere across the area,
though still some -PL at KCLT and still liquid at KAND. Will
transition to all -SN with some SN/possible +SN off and on.
Continued previous trend of TEMPO for 1/2SM vsby with the SN, but
mainly widespread IFR overnight with improvement toward 12z. Should
be VFR everywhere by 18z. Other issue will be the winds, NNE around
10kt with gusts 15-20kt. Winds will back to the NW later today and
should lighten by the end of the period to between 5-10kt.

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...

            08-14Z        14-20Z        20-02Z        02-06Z
KCLT       High  88%     High  87%     High 100%     High 100%
KGSP       High  90%     High  89%     High 100%     High 100%
KAVL       High  82%     High  84%     High 100%     High 100%
KHKY       High  86%     High  82%     High 100%     High 100%
KGMU       High  82%     High  83%     High 100%     High 100%
KAND       High  86%     High  82%     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 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 this afternoon for GAZ010-
     017-018-026-028-029.
NC...Winter Storm Warning until 1 PM EST this afternoon for NCZ033-
     035>037-048>053-056>059-062>065-068>072-082-501>510.
     Wind Chill Advisory from 7 PM this evening to noon EST Sunday
     for NCZ048-051>053-058-059-062>065-501-503-505-507-509.
     Wind Chill Warning from 7 PM this evening to noon EST Sunday
     for NCZ033-049-050.
SC...Winter Storm Warning until 1 PM EST this afternoon for
     SCZ001>014-019.

&&

SYNOPSIS...ARK
NEAR TERM...TDP
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...TDP
Hazardous weather outlook, Jan 6, 3:01 PM EST, 12 hours 41 minutes before
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

In the hours before

Local storm report, Jan 7, 3:21 AM EST, 21 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
321 AM EST SAT JAN 07 2017

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

0900 PM     SNOW             2 W CLARKESVILLE        34.61N  83.56W
01/06/2017  M1.0 INCH        HABERSHAM          GA   SOCIAL MEDIA

&&

LEV
Local storm report, Jan 7, 3:22 AM EST, 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
322 AM EST SAT JAN 07 2017

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

1200 AM     SNOW             CONOVER                 35.71N  81.22W
01/07/2017  M2.0 INCH        CATAWBA            NC   SOCIAL MEDIA

&&

LEV
Local storm report, Jan 7, 3:23 AM EST, 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
323 AM EST SAT JAN 07 2017

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

0300 AM     SNOW             IRON STATION            35.44N  81.16W
01/07/2017  M5.0 INCH        LINCOLN            NC   SOCIAL MEDIA

&&

LEV
Local storm report, Jan 7, 3:29 AM EST, 13 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
329 AM EST SAT JAN 07 2017

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

1230 AM     SNOW             4 E CHESNEE             35.14N  81.80W
01/07/2017  M2.2 INCH        CHEROKEE           SC   SOCIAL MEDIA

&&

LEV
Local storm report, Jan 7, 3:36 AM EST, 6 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
336 AM EST SAT JAN 07 2017

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

0245 AM     SNOW             3 W PICKENS             34.88N  82.76W
01/07/2017  M4.5 INCH        PICKENS            SC   COCORAHS

&&

LEV
Local storm report, Jan 7, 3:41 AM EST, 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
341 AM EST SAT JAN 07 2017

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

1227 AM     SNOW             4 NE FOREST CITY        35.38N  81.82W
01/07/2017  M3.0 INCH        RUTHERFORD         NC   COCORAHS

&&

LEV

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 7, 3:42 AM ESTWind Chill WarningGSPAvery, Mitchell, Yancey32 hr
Jan 7, 3:04 PM ESTWinter Weather AdvisoryGSPAlexander, Avery, Buncombe, Burke, Cabarrus, Caldwell and 22 more21 hr
Jan 7, 6:02 AM ESTWinter Weather AdvisoryGSPAbbeville, Chester, Greenwood, Laurens, Union7 hr

Nearby

Wind Chill Advisories in North Carolina, 2017Wind Chill Advisories in Georgia, 2017Wind Chill Advisories in South Carolina, 2017Every wind chill advisory in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.