Alert archive / North Carolina / Frost Advisories in 2021

Frost Advisory 6, NWS Greenville-Spartanburg, SC

October 17, 202115 counties in North Carolina; Rabun County, Georgia

NWS Greenville-Spartanburg, SC issued this frost advisory at Oct 17, 2021, 3:43 AM EDT for 15 counties in North Carolina; Rabun County, Georgia. It took effect at Oct 18, 2021, 12:00 AM EDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Oct 17, 2021, 3:43 AM EDT (07:43 UTC)
In effect from
Oct 18, 2021, 12:00 AM EDT
Expired
Oct 18, 2021, 9:00 AM EDT
In force
9 hr
Issued by
NWS Greenville-Spartanburg, SC

Counties Rabun County, GA, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Swain County, NC, Transylvania County, NC, Yancey County, NC

The radar

The Greer radar (KGSP), 86 km from the middle of the area, began a volume at 07:47 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, 7.7 hours before the alert went out and 255 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 2021-10-17Temperature 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 2021-10-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -131 square meters per square second.1939587897117Sfc1 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
1713 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
-131 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

408 
WWUS72 KGSP 170743
NPWGSP

URGENT - WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
343 AM EDT Sun Oct 17 2021

NCZ048-049-051>053-058-059-062>064-172000-
/O.NEW.KGSP.FR.Y.0006.211018T0400Z-211018T1300Z/
Madison-Yancey-Swain-Haywood-Buncombe-Graham-Northern Jackson-
Macon-Southern Jackson-Transylvania-
Including the cities of Faust, Mars Hill, Marshall, Walnut, 
Allenstand, Hot Springs, Luck, Swiss, Burnsville, Celo, 
Micaville, Ramseytown, Busick, Alarka, Almond, Bryson City, 
Luada, Wesser, Waynesville, Waterville, Canton, Cruso, 
Cove Creek, Asheville, Robbinsville, Stecoah, Cullowhee, 
Tuckasegee, Sylva, Franklin, Rainbow Springs, Kyle, Highlands, 
Wolf Mountain, Cashiers, Brevard, Cedar Mountain, 
and Little River
343 AM EDT Sun Oct 17 2021

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM EDT
MONDAY...

* WHAT...Temperatures falling into the mid 30s will result in 
  frost formation.

* WHERE...Madison, Yancey, Swain, Haywood, Buncombe, Graham,
  Jackson, Macon, and Transylvania Counties in North Carolina.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...Isolated spots, particularly in the
  valleys, may fall to freezing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
Wimberley
4 follow-up statements
898 
WWUS72 KGSP 171743
NPWGSP

URGENT - WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
143 PM EDT Sun Oct 17 2021

NCZ033-050-065-501-503-505-180300-
/O.EXA.KGSP.FR.Y.0006.211018T0400Z-211018T1300Z/
Avery-Mitchell-Henderson-Caldwell Mountains-Burke Mountains-
McDowell Mountains-
Including the cities of Ingalls, Banner Elk, Newland, 
Spruce Pine, Poplar, Hendersonville, Fletcher, Dana, 
East Flat Rock, Tuxedo, Etowah, Jonas Ridge, Ashford, Woodlawn, 
and Old Fort
143 PM EDT Sun Oct 17 2021

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM EDT
MONDAY...

* WHAT...Temperatures falling into the mid 30s will result in
  frost formation.

* WHERE...Western North Carolina mountains and northern 
  foothills.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...Isolated spots, particularly in sheltered
  valleys, may briefly fall to freezing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

NCZ048-049-051>053-058-059-062>064-180300-
/O.CON.KGSP.FR.Y.0006.211018T0400Z-211018T1300Z/
Madison-Yancey-Swain-Haywood-Buncombe-Graham-Northern Jackson-
Macon-Southern Jackson-Transylvania-
Including the cities of Faust, Mars Hill, Marshall, Walnut, 
Allenstand, Hot Springs, Luck, Swiss, Burnsville, Celo, 
Micaville, Ramseytown, Busick, Alarka, Almond, Bryson City, 
Luada, Wesser, Waynesville, Waterville, Canton, Cruso, 
Cove Creek, Asheville, Robbinsville, Stecoah, Cullowhee, 
Tuckasegee, Sylva, Franklin, Rainbow Springs, Kyle, Highlands, 
Wolf Mountain, Cashiers, Brevard, Cedar Mountain, 
and Little River
143 PM EDT Sun Oct 17 2021

...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM
EDT MONDAY...

* WHAT...Temperatures falling into the mid 30s will result in 
  frost formation.

* WHERE...Western North Carolina mountains and northern foothills.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...Isolated spots, particularly in sheltered
  valleys, may briefly fall to freezing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
Munroe
818 
WWUS72 KGSP 172154
NPWGSP

URGENT - WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
554 PM EDT Sun Oct 17 2021

GAZ010-180900-
/O.EXA.KGSP.FR.Y.0006.211018T0400Z-211018T1300Z/
Rabun-
Including the cities of Clayton, Pine Mountain, and Mountain City
554 PM EDT Sun Oct 17 2021

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM EDT
MONDAY...

* WHAT...Temperatures falling into the mid 30s overnight will 
  result in areas of frost formation.

* WHERE...Rabun County in northeast Georgia.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if left
  uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

NCZ033-048>053-058-059-062>065-501-503-505-180900-
/O.CON.KGSP.FR.Y.0006.211018T0400Z-211018T1300Z/
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
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, Asheville, 
Robbinsville, Stecoah, Cullowhee, Tuckasegee, Sylva, Franklin, 
Rainbow Springs, Kyle, Highlands, Wolf Mountain, Cashiers, 
Brevard, Cedar Mountain, Little River, Hendersonville, Fletcher, 
Dana, East Flat Rock, Tuxedo, Etowah, Jonas Ridge, Ashford, 
Woodlawn, and Old Fort
554 PM EDT Sun Oct 17 2021

...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM
EDT MONDAY...

* WHAT...Temperatures falling into the lower to middle 30s will
  result in areas of frost formation.

* WHERE...The mountains of western North Carolina.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...Isolated spots, particularly in sheltered 
  valleys, may briefly fall to freezing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

HG
801 
WWUS72 KGSP 180144
NPWGSP

URGENT - WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
944 PM EDT Sun Oct 17 2021

GAZ010-NCZ033-048>053-058-059-062>065-501-503-505-181000-
/O.CON.KGSP.FR.Y.0006.211018T0400Z-211018T1300Z/
Rabun-Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
Including the cities of Clayton, Pine Mountain, Mountain City, 
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, Asheville, Robbinsville, Stecoah, 
Cullowhee, Tuckasegee, Sylva, Franklin, Rainbow Springs, Kyle, 
Highlands, Wolf Mountain, Cashiers, Brevard, Cedar Mountain, 
Little River, Hendersonville, Fletcher, Dana, East Flat Rock, 
Tuxedo, Etowah, Jonas Ridge, Ashford, Woodlawn, and Old Fort
944 PM EDT Sun Oct 17 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM EDT MONDAY...

* WHAT...Temperatures falling into the lower to middle 30s will 
  result in areas of frost formation.

* WHERE...The mountains of western North Carolina and Rabun County
  in northeast Georgia.

* WHEN...From midnight tonight to 9 AM EDT Monday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...Isolated spots, particularly in sheltered
  valleys, may see temperatures briefly fall to the freezing mark.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Finalize steps now to protect tender plants from the cold.

&&

$$

HG
856 
WWUS72 KGSP 180654
NPWGSP

URGENT - WEATHER MESSAGE
National Weather Service Greenville-Spartanburg SC
254 AM EDT Mon Oct 18 2021

GAZ010-NCZ033-048>053-058-059-062>065-501-503-505-181300-
/O.CON.KGSP.FR.Y.0006.000000T0000Z-211018T1300Z/
Rabun-Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
Including the cities of Clayton, Pine Mountain, Mountain City, 
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, Asheville, Robbinsville, Stecoah, 
Cullowhee, Tuckasegee, Sylva, Franklin, Rainbow Springs, Kyle, 
Highlands, Wolf Mountain, Cashiers, Brevard, Cedar Mountain, 
Little River, Hendersonville, Fletcher, Dana, East Flat Rock, 
Tuxedo, Etowah, Jonas Ridge, Ashford, Woodlawn, and Old Fort
254 AM EDT Mon Oct 18 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM EDT THIS MORNING...

* WHAT...Temperatures falling into the lower to middle 30s will 
  result in areas of frost formation.

* WHERE...The mountains of western North Carolina and Rabun 
  County in northeast Georgia.

* WHEN...Until 9 AM EDT this morning.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...Isolated spots, particularly in sheltered 
  valleys, may see temperatures briefly fall to the freezing 
  mark.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Finalize steps now to protect tender plants from the cold.

&&

$$

Krentz

What forecasters said that day

The local office's own words before this frost 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 frost advisory went out at Oct 17, 3:39 AM EDT, 4 minutes earlier.

Area forecast discussion, Oct 17, 3:39 AM EDT, 4 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
339 AM EDT Sun Oct 17 2021

.SYNOPSIS...
Cool and dry high pressure will continue to build into the region
today and linger through Monday. A warming trend is then expected
through mid week before another cold front with limited moisture
crosses the area late in the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM: High pressure centered over the southern Plains
continues to build into the CWA, promoting gusty NW winds across
the mountain obs sites. The near-advisory gusts seen at the
high-elevation NC EcoNet sites have mostly tapered off, but the
mountains in general will remain quite breezy through the end of the
day. Almost all guidance depicts temps on a steady downward trend
thru dawn, but only the ridgetop sites are currently reporting temps
in the 30s. Seems the winds are preventing decoupling elsewhere;
revised morning mins are a tad warmer for the most part. This is
of interest mainly for frost potential, which seems even smaller
than we had been expecting, and a mention is only warranted in
a few sheltered spots. It is too late for a frost advisory to do
any good anyway--at least for this morning.

Dry conditions and clear skies are on tap for the CWA today;
a few ridges may see some upslope clouds at times but precip
chances are practically zero. Much cooler temps still are expected,
though in light of guidance performance yesterday and the expected
downsloping, have raised maxes a degree or so from the previous
fcst across the Piedmont. Diurnal mixing thus looks a little more
likely to bring down the very dry air aloft, so dewpoints are
expected to crash in portions of the Piedmont this afternoon. RH
looks to bottom out at or just above 25%. Fuels are pretty dry with
the recent lack of wetting rain in most areas, such that afternoon
moisture readings may reach critically low levels. In light of the
breezy conditions, wildfire danger will be slightly elevated today,
but criteria for a Fire Danger Statement are not technically met.

The surface high will shift east and become centered near the
southern Appalachians tonight. Continued clear skies suggest
better radiation and Monday morning mins falling a few degrees
cooler than this morning's readings. Winds should diminish further
particularly in our more western ranges, nearer the high and with
broader valleys. We will hoist a Frost Advisory for tonight for
the TN border counties from Yancey County southwest, plus the
upper French Broad and Little Tennessee valleys.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 100 AM EDT Sunday: Within the dry WNW flow aloft and sfc
ridging, sunshine is on tap for Monday.  After a chilly start,
maximum temperatures will rebound to around the mid-October climo.
Sfc hipres lingers across the region on Tuesday with perhaps some
high clouds mixing in with the sunshine as high level moisture
starts to top the very low amplitude ridging aloft.  The warming
trend is expected to continue with Piedmont middle 70s for highs.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 130 AM EDT Sunday: Dry and warm wx is still on tap for
Wednesday as weak return flow gets underway. Pretty solid upper 70s
are expected for the piedmont high temperatures.  17/00z op GFS
depicts frontal band showers possibly making inroads into the
mountains by Thursday afternoon.  It will also remain mild with
another day of upper 70s in the Piedmont.  The medium range model
consensus and WPC guidance progresses with the cold front through
the region on Friday with a limited amount of moisture accompanying
it's passage followed by a dry post-frontal day on Saturday.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: VFR, and with the exception of SCT upslope
clouds along NW-facing mtn ridges, the region is likely to remain
SKC thru the period. Dry high pressure building into the region
thru today will maintain at least occasional gusts during that
time. These look frequent enough to mention at all sites except
KAND. Chilly temps will accompany the incoming airmass, and with
winds relaxing tonight, mountain valleys appear likely to see some
frost by daybreak Monday.

Outlook: VFR conditions with mainly light winds will prevail
through at least Wednesday. A cold front may approach from the
northwest on Thursday.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Frost Advisory from midnight tonight to 9 AM EDT Monday for
     NCZ048-049-051>053-058-059-062>064.
SC...None.

&&

SYNOPSIS...CSH
NEAR TERM...Wimberley
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...Wimberley
Hazardous weather outlook, Oct 16, 4:47 PM EDT, 10 hours 56 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
447 PM EDT Sat Oct 16 2021

NCZ033-048>053-058-059-062>064-172100-
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-
447 PM EDT Sat Oct 16 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...Sunday through Friday.

Clear skies and light winds will allow temperatures to fall into the
low to mid 30s early Monday morning. These conditions will lead to
frost development in parts of the North Carolina mountains.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-065-068>072-082-
501>510-SCZ001>014-019-172100-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Catawba-Rowan-Henderson-Cleveland-Lincoln-Gaston-Mecklenburg-
Cabarrus-Union NC-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-Union SC-Chester-Greenwood-
447 PM EDT Sat Oct 16 2021

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

.DAY ONE...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.

Nearby

Frost Advisories in North Carolina, 2021Frost Advisories in Georgia, 2021Every frost advisory in 2021

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.