Alert archive / Georgia / Dense Fog Advisories in 2021

Dense Fog Advisory 6, NWS Charleston, SC

February 18, 2021Effingham County, Long County, Georgia

NWS Charleston, SC issued this dense fog advisory at Feb 18, 2021, 3:38 AM EST for Effingham County, Long County, Georgia. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Feb 18, 2021, 3:38 AM EST (08:38 UTC)
Expired
Feb 18, 2021, 7:20 AM EST
In force
4 hr
Issued by
NWS Charleston, SC

Counties Effingham County, GA, Long County, GA

The radar

The Charleston,SC radar (KCLX), 81 km from the middle of the area, began a volume at 08:37 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

Charleston AFB, SC (KCHS), launched 00:00Z, 8.6 hours before the alert went out and 172 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, Charleston AFB, SC at 00:00Z on 2021-02-18Temperature 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, Charleston AFB, SC at 00:00Z on 2021-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 564 square meters per square second.1939587897Sfc1 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
560 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
564 m²/s²
0-3 km storm-relative helicity
491 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Charleston, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 18, 1:25 AM ESTMarine Dense Fog AdvisoryCHS26 hr
Feb 18, 3:37 AM ESTSmall Craft AdvisoryCHS41 hr
Feb 18, 7:15 AM ESTFlash Flood WatchCHSAllendale, Berkeley, Colleton, Dorchester, Hampton20 hr
Feb 18, 10:40 AM ESTRiver Flood WarningCHSAllendale21 days
Feb 18, 4:40 PM ESTAreal Flood AdvisoryCHSAllendale, Colleton, Hampton110 min
Feb 18, 5:17 PM ESTAreal Flood AdvisoryCHSDorchester118 min
Feb 18, 5:44 PM ESTAreal Flood AdvisoryCHSBerkeley2 hr
Feb 17, 9:23 PM ESTRiver Flood WarningCHSBryan, Bulloch, Chatham, Effingham25 days
Feb 18, 3:29 PM ESTAreal Flood AdvisoryCHSBulloch, Screven114 min

Nearby

Dense Fog Advisories in Georgia, 2021Dense Fog Advisories in South Carolina, 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.