Alert archive / Georgia / Dense Fog Advisories in 2021

Dense Fog Advisory 12, NWS Atlanta, GA

August 27, 20216 counties in Georgia

NWS Atlanta, GA issued this dense fog advisory at Aug 27, 2021, 2:50 AM EDT for 6 counties in Georgia. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Aug 27, 2021, 2:50 AM EDT (06:50 UTC)
Expired: Aug 27, 2021, 10:00 AM EDT
In force: 7 hr
Issued by: NWS Atlanta, GA

Counties Fannin County, GA, Gilmer County, GA, Lumpkin County, GA, Towns County, GA, Union County, GA, White County, GA

The radar

The Atlanta radar (KFFC), 162 km from the middle of the area, began a volume at 06:48 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, 6.8 hours before the alert went out and 160 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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 Atlanta, GA wrote its last area forecast discussion before this dense fog advisory went out at Aug 27, 1:22 AM EDT, 1 hour 28 minutes earlier.

Area forecast discussion, Aug 27, 1:22 AM EDT, 1 hour 28 minutes before

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Hazardous weather outlook, Aug 26, 10:52 PM EDT, 3 hours 58 minutes before

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In the hours before

Special weather statement, Aug 26, 9:14 PM EDT, 5 hours 36 minutes before

Special Weather Statement
National Weather Service Peachtree City GA
914 PM EDT Thu Aug 26 2021

GAZ079-080-090>093-270145-
Macon GA-Schley GA-Chattahoochee GA-Taylor GA-Marion GA-Talbot GA-
914 PM EDT Thu Aug 26 2021

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF NORTHWESTERN MACON,
NORTHERN MARION, NORTHEASTERN CHATTAHOOCHEE, NORTHWESTERN SCHLEY,
SOUTHERN TALBOT AND TAYLOR COUNTIES THROUGH 945 PM EDT...

At 914 PM EDT...a strong thunderstorm was near Rupert, or near
Butler...moving west at 20 mph.

HAZARD...Up to 40 mph wind...frequent cloud to ground lightning and
         heavy rain.

SOURCE...Radar indicated.

IMPACT...Expect minor damage to tree limbs and blowing around of
         light...unsecured objects. Heavy rain may cause temporary
         street flooding especially in poor drainage areas.

Some locations in the path of this storm include
Butler, Talbotton, Reynolds, Ideal, Junction City, Geneva, Brantley,
Juniper, Baldwinville, Rupert, Charing, Oakland, Olive Branch, Po
Biddy Crossroads, Potterville, Mauk, Box Springs, Howard, Tazewell
and Marion Estates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People outdoors should seek shelter immediately. If you can hear
thunder...you are close enough to be struck by lightning. Motorists
should slow down and be prepared for possible loss of control due to
hydroplaning.

LAT...LON 3256 8409 3235 8417 3237 8472 3277 8458
TIME...MOT...LOC 0114Z 106DEG 18KT 3247 8422

MAX HAIL SIZE...
MAX WIND GUST...40MPH

Local storm report, Aug 26, 10:28 PM EDT, 4 hours 22 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 8:22 PM EDT	Special Weather Statement	FFC	Crawford, Peach	23 min
Aug 26, 8:31 PM EDT	Special Weather Statement	FFC	Schley	14 min
Aug 26, 8:38 PM EDT	Special Weather Statement	FFC	Macon	22 min
Aug 26, 9:14 PM EDT	Special Weather Statement	FFC	Talbot, Taylor	31 min
Aug 27, 4:10 PM EDT	Special Weather Statement	FFC	Crisp	20 min
Aug 27, 4:11 PM EDT	Special Weather Statement	FFC	Ben Hill	34 min
Aug 27, 4:16 PM EDT	Special Weather Statement	FFC	Washington, Wilkinson	29 min
Aug 27, 4:20 PM EDT	Special Weather Statement	FFC	Monroe	25 min
Aug 27, 4:57 PM EDT	Special Weather Statement	FFC	Hancock, Putnam, Warren	33 min
Aug 27, 4:59 PM EDT	Special Weather Statement	FFC	Webster	31 min
Aug 27, 5:19 PM EDT	Special Weather Statement	FFC	Harris, Meriwether, Troup	26 min
Aug 27, 5:39 PM EDT	Special Weather Statement	FFC	Butts, Jasper	36 min
Aug 27, 5:55 PM EDT	Special Weather Statement	FFC	Muscogee	35 min
Aug 27, 6:16 PM EDT	Special Weather Statement	FFC	Butts, Clarke, Henry, Jasper, Morgan, Newton and 3 more	29 min
Aug 27, 6:39 PM EDT	Special Weather Statement	FFC	Muscogee	36 min
Aug 27, 6:45 PM EDT	Special Weather Statement	FFC	Clarke, Clayton, Henry, Newton, Oconee, Rockdale and 1 more	30 min
Aug 27, 7:19 PM EDT	Special Weather Statement	FFC	Barrow, DeKalb, Fulton, Gwinnett, Rockdale, Walton	11 min

Nearby

Dense Fog Advisories in Georgia, 2021 Every 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.