Alert archive / Georgia / Special Weather Statements in 2021

Special Weather Statement, NWS Atlanta, GA

June 30, 2021Forsyth County, Georgia

NWS Atlanta, GA issued this special weather statement at Jun 30, 2021, 8:04 PM EDT for Forsyth County, Georgia. It was in force for 26 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, 8:04 PM EDT (00:04 UTC)
Expired
Jun 30, 2021, 8:30 PM EDT
In force
26 min
Issued by
NWS Atlanta, GA
Wind
40

County Forsyth County, GA

The radar

The Atlanta radar (KFFC), 86 km from the middle of the area, began a volume at 00:06 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, 0.1 hours before the alert went out and 83 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.

959 
WWUS82 KFFC 010004
SPSFFC

Special Weather Statement
National Weather Service Peachtree City GA
804 PM EDT Wed Jun 30 2021
 
GAZ021-033-034-010030-
North Fulton GA-Cherokee GA-Gwinnett GA-
804 PM EDT Wed Jun 30 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTH FULTON...SOUTHERN CHEROKEE
AND WESTERN GWINNETT COUNTIES UNTIL 830 PM EDT...

At 804 PM EDT...a strong thunderstorm was near Alpharetta, or 14
miles southwest of Cumming...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, Johns Creek, Alpharetta, Milton, Duluth,
Norcross, Berkeley Lake, Mountain Park and Birmingham.

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 3415 8426 3411 8426 3410 8423 3410 8422
      3409 8420 3402 8413 3393 8422 3404 8441
      3416 8442 3418 8429
TIME...MOT...LOC 0004Z 121DEG 10KT 3402 8426 

WIND...40MPH

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 8:31 PM EDTSpecial Weather StatementFFCCobb29 min
Jun 30, 8:33 PM EDTSpecial Weather StatementFFCCobb27 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.