Alert archive / Georgia / Dense Fog Advisories in 2021

Dense Fog Advisory 2, NWS Atlanta, GA

January 2, 202126 counties in Georgia

NWS Atlanta, GA issued this dense fog advisory at Jan 2, 2021, 12:44 AM EST for 26 counties in Georgia. It took effect at Jan 2, 2021, 1:00 AM EST. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Jan 2, 2021, 12:44 AM EST (05:44 UTC)
In effect from
Jan 2, 2021, 1:00 AM EST
Expired
Jan 2, 2021, 10:00 AM EST
In force
9 hr
Issued by
NWS Atlanta, GA
All 26 counties

Banks County, GA, Barrow County, GA, Cherokee County, GA, Clarke County, GA, Dawson County, GA, DeKalb County, GA, Forsyth County, GA, Fulton County, GA, Greene County, GA, Gwinnett County, GA, Hall County, GA, Jackson County, GA, Jasper County, GA, Lumpkin County, GA, Madison County, GA, Morgan County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Pickens County, GA, Putnam County, GA, Rockdale County, GA, Taliaferro County, GA, Walton County, GA, White County, GA, Wilkes County, GA

The radar

The Atlanta radar (KFFC), 103 km from the middle of the area, began a volume at 05:48 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, 5.7 hours before the alert went out and 98 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 2021-01-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 2021-01-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 147 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
4 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
616 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

388 
WWUS72 KFFC 020544
NPWFFC

URGENT - WEATHER MESSAGE
National Weather Service Peachtree City GA
1244 AM EST Sat Jan 2 2021

GAZ013>016-021>025-027-033>039-045>051-059-060-021345-
/O.NEW.KFFC.FG.Y.0002.210102T0600Z-210102T1500Z/
Pickens-Dawson-Lumpkin-White-Cherokee-Forsyth-Hall-Banks-Jackson-
Madison-North Fulton-Gwinnett-Barrow-Clarke-Oconee-Oglethorpe-
Wilkes-DeKalb-Rockdale-Walton-Newton-Morgan-Greene-Taliaferro-
Jasper-Putnam-
Including the cities of Dahlonega, Cleveland, Gainesville, 
Atlanta, Lawrenceville, Athens, Decatur, Conyers, and Covington
1244 AM EST Sat Jan 2 2021

...DENSE FOG ADVISORY IN EFFECT UNTIL 10 AM EST THIS MORNING...

* WHAT...Visibility one quarter to one half mile in dense fog.

* WHERE...Portions of northeast Georgia.

* WHEN...Until 10 AM EST this morning.

* IMPACTS...Hazardous driving conditions due to low visibility.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

&&

$$

The office that day

Everything else NWS Atlanta, GA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 1, 7:11 PM ESTSpecial Weather StatementFFCMontgomery, Toombs34 min
Jan 1, 7:18 PM ESTSpecial Weather StatementFFCEmanuel27 min
Jan 2, 11:17 AM ESTFlash Flood WatchFFCBaldwin, Bibb, Bleckley, Crisp, Dodge, Dooly and 26 more11 hr
Jan 2, 6:51 PM ESTSpecial Weather StatementFFCTelfair, Wheeler24 min

Nearby

Dense Fog Advisories in Georgia, 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.