Alert archive / North Carolina / Dense Fog Advisories in 2021

Dense Fog Advisory 4, NWS Morristown, TN

August 27, 2021Polk County, Tennessee; Cherokee County, Clay County, North Carolina

NWS Morristown, TN issued this dense fog advisory at Aug 27, 2021, 3:11 AM EDT for Polk County, Tennessee; Cherokee County, Clay County, North Carolina. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Aug 27, 2021, 3:11 AM EDT (07:11 UTC)
Expired
Aug 27, 2021, 10:00 AM EDT
In force
7 hr
Issued by
NWS Morristown, TN

Counties Cherokee County, NC, Clay County, NC, Polk County, TN

The radar

The Knoxville radar (KMRX), 135 km from the middle of the area, began a volume at 07:11 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, 7.2 hours before the alert went out and 196 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 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 853 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.1939Sfc1 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
853 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
1324 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
48 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 dense fog advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Morristown, TN wrote its last area forecast discussion before this dense fog advisory went out at Aug 26, 7:18 PM EDT, 7 hours 53 minutes earlier.

Area forecast discussion, Aug 26, 7:18 PM EDT, 7 hours 53 minutes before
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Hazardous weather outlook, Aug 26, 3:57 AM EDT, 23 hours 14 minutes before
Hazardous Weather Outlook
National Weather Service Morristown TN
357 AM EDT Thu Aug 26 2021

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-270800-
Cherokee-Clay-Scott-Campbell-Claiborne-Hancock-Hawkins-Sullivan-
Johnson-Morgan-Anderson-Union-Grainger-Hamblen-Northwest Cocke-
Cocke Smoky Mountains-Northwest Greene-Southeast Greene-
Washington-Unicoi-Northwest Carter-Southeast Carter-Roane-Loudon-
Knox-Jefferson-Northwest Blount-Blount Smoky Mountains-
North Sevier-Sevier Smoky Mountains-Sequatchie-Bledsoe-Rhea-Meigs-
McMinn-Northwest Monroe-Southeast Monroe-Marion-Hamilton-Bradley-
West Polk-East Polk-Lee-Wise-Russell-
357 AM EDT Thu Aug 26 2021 /257 AM CDT Thu Aug 26 2021/

This Hazardous Weather Outlook is for portions of southwest North
Carolina...east Tennessee and southwest Virginia.

.DAY ONE...Today and Tonight

Isolated to scattered showers and thunderstorms are forecast
today, a few of which could be strong to severe with damaging
winds, frequent lightning, and heavy rainfall rates being the
primary threats.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time. Please relay any
reports of thunderstorm damage or severe weather.

The office that day

Everything else NWS Morristown, TN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 27, 7:21 PM EDTSpecial Weather StatementMRXSullivan39 min
Aug 26, 8:08 PM EDTAreal Flood AdvisoryMRXRussell, Scott3 hr
Aug 27, 6:15 PM EDTSpecial Weather StatementMRXWashington45 min

Nearby

Dense Fog Advisories in North Carolina, 2021Dense Fog Advisories in Tennessee, 2021Every dense fog 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.