Alert archive / Georgia / Special Weather Statements in 2021

Special Weather Statement, NWS Atlanta, GA

June 30, 2021Cobb County, Georgia

NWS Atlanta, GA issued this special weather statement at Jun 30, 2021, 8:33 PM EDT for Cobb County, Georgia. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 30, 2021, 8:33 PM EDT (00:33 UTC)
Expired
Jun 30, 2021, 9:00 PM EDT
In force
27 min
Issued by
NWS Atlanta, GA
Wind
40

County Cobb County, GA

The radar

The Atlanta radar (KFFC), 77 km from the middle of the area, began a volume at 00:33 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, 0.6 hours before the alert went out and 74 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 2021-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1062 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 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
1062 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1394 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
-31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

762 
WWUS82 KFFC 010033
SPSFFC

Special Weather Statement
National Weather Service Peachtree City GA
833 PM EDT Wed Jun 30 2021
 
GAZ021-032-033-045-010100-
North Fulton GA-Cobb GA-Cherokee GA-DeKalb GA-
833 PM EDT Wed Jun 30 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTH FULTON...NORTHEASTERN
COBB...SOUTHERN CHEROKEE AND NORTHWESTERN DEKALB COUNTIES UNTIL 900
PM EDT...

At 833 PM EDT...a strong thunderstorm was over Roswell, or 12 miles
east of Marietta...moving northwest at 10 mph.

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

  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
Sandy Springs, Roswell, Alpharetta, Dunwoody and Sweat Mountain. 

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 3402 8421 3400 8423 3400 8424 3399 8425
      3399 8426 3397 8426 3392 8431 3401 8448
      3413 8444 3413 8430
TIME...MOT...LOC 0033Z 123DEG 7KT 3400 8433 

WIND...40MPH

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 8:04 PM EDTSpecial Weather StatementFFCForsyth26 min
Jun 30, 8:31 PM EDTSpecial Weather StatementFFCCobb29 min
Jun 30, 8:37 PM EDTSevere Thunderstorm WarningFFCCobb38 min
Jul 1, 7:51 PM EDTSpecial Weather StatementFFCBibb24 min

Nearby

Special Weather Statements in Georgia, 2021Every special weather statement 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.