Alert archive / North Carolina / Freeze Watches in 2021

Freeze Watch 3, NWS Greenville-Spartanburg, SC

April 21, 202117 counties in North Carolina

NWS Greenville-Spartanburg, SC issued this freeze watch at Apr 21, 2021, 8:58 PM EDT for 17 counties in North Carolina. It took effect at Apr 23, 2021, 2:00 AM EDT. It was in force for .

The area

The counties it named.

The facts

Issued
Apr 21, 2021, 8:58 PM EDT (00:58 UTC)
In effect from
Apr 23, 2021, 2:00 AM EDT
Expired
Apr 22, 2021, 3:35 AM EDT
In force
Issued by
NWS Greenville-Spartanburg, SC

Counties 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, Polk County, NC, Rutherford County, NC, Swain County, NC, Transylvania County, NC, Yancey County, NC

The radar

The Greer radar (KGSP), 83 km from the middle of the area, began a volume at 00:59 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 1.0 hours before the alert went out and 305 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, Peachtre/Fal Fld, GA at 00:00Z on 2021-04-22Temperature 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, Peachtre/Fal Fld, GA at 00:00Z on 2021-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 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
2126 m above ground
0-6 km bulk shear
78 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
57 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 freeze watch 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 freeze watch went out at Apr 21, 7:12 PM EDT, 1 hour 46 minutes earlier.

Area forecast discussion, Apr 21, 7:12 PM EDT, 1 hour 46 minutes before
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Hazardous weather outlook, Apr 21, 4:01 PM EDT, 4 hours 57 minutes before
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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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        Please try again in a few minutes.
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The office that day

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

IssuedProductOfficeCountiesLasted
Apr 22, 3:35 AM EDTFrost AdvisoryGSPCabarrus, Cleveland, Gaston, Mecklenburg, Polk, Rutherford and 1 more29 hr
Apr 22, 3:35 AM EDTFreeze WarningGSPAlexander, Avery, Buncombe, Burke, Caldwell, Catawba and 15 more29 hr

Nearby

Freeze Watches in North Carolina, 2021Every freeze watch 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.