Alert archive / Georgia / Special Weather Statements in 2012

Special Weather Statement, NWS Atlanta, GA

August 1, 2012Forsyth County, Georgia

NWS Atlanta, GA issued this special weather statement at Aug 1, 2012, 4:16 PM EDT for Forsyth County, Georgia. It was in force for 44 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 1, 2012, 4:16 PM EDT (20:16 UTC)
Expired
Aug 1, 2012, 5:00 PM EDT
In force
44 min
Issued by
NWS Atlanta, GA

County Forsyth County, GA

The radar

The Atlanta radar (KFFC), 104 km from the middle of the area, began a volume at 20:19 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.

What was reported inside it

TimeReportWhereRemark
Aug 1, 4:37 PM EDTTSTM WND DMGCumming, GAFORSYTH EMA RELAYED A REPORT OF TREES DOWN ON HOUSES...POWERLINES DOWN...STREET LIGHTS AND STOPLIGHTS DOWNED BY THUNDERSTORM WIND ACROSS THE COUNTY.
Aug 1, 4:47 PM EDTHAIL 0.753 Ssw Cumming, GA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 8.3 hours before the alert went out and 100 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 12:00Z on 2012-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1144 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 12:00Z on 2012-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.193958Sfc1 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
1144 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
595 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

121 
WWUS82 KFFC 012016
SPSFFC

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
416 PM EDT WED AUG 1 2012

GAZ022-023-033>035-012100-
416 PM EDT WED AUG 1 2012

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 40 MPH WINDS
IN BARROW...FORSYTH...GWINNETT...HALL AND FULTON COUNTIES UNTIL 500
PM EDT...

AT 414 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER CUMMING...MOVING SOUTHEAST AT 25 MPH.

THESE STORMS HAVE THE POTENTIAL TO PRODUCE DIME SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS THEY MOVE
ACROSS BARROW...FORSYTH...GWINNETT...HALL AND FULTON COUNTIES THROUGH
500 PM EDT. HEAVY DOWNPOURS WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3413 8381 3407 8377 3407 8375 3405 8373
      3395 8421 3429 8423 3430 8398
TIME...MOT...LOC 2016Z 334DEG 20KT 3422 8411

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 8:41 PM EDTSpecial Weather StatementFFCCatoosa, Walker, Whitfield64 min
Jul 31, 10:51 PM EDTSpecial Weather StatementFFCTowns, Union24 min
Jul 31, 11:18 PM EDTSpecial Weather StatementFFCLumpkin, Towns, Union, White27 min
Aug 1, 3:33 PM EDTSpecial Weather StatementFFCChattooga57 min
Aug 1, 3:51 PM EDTSevere Thunderstorm WarningFFCChattooga, Floyd39 min
Aug 1, 4:21 PM EDTSpecial Weather StatementFFCCatoosa, Whitfield39 min
Aug 1, 4:23 PM EDTSevere Thunderstorm WarningFFCForsyth, Gwinnett, Hall52 min
Aug 1, 4:28 PM EDTSpecial Weather StatementFFCFloyd47 min
Aug 1, 4:48 PM EDTSevere Thunderstorm WarningFFCFloyd42 min
Aug 1, 4:57 PM EDTSpecial Weather StatementFFCGordon, Murray33 min
Aug 1, 5:10 PM EDTSpecial Weather StatementFFCDawson50 min
Aug 1, 5:13 PM EDTSevere Thunderstorm WarningFFCGilmer, Gordon, Murray, Pickens47 min
Aug 1, 6:05 PM EDTSpecial Weather StatementFFCGilmer, Pickens40 min
Aug 1, 6:17 PM EDTSpecial Weather StatementFFCDooly28 min
Aug 1, 6:19 PM EDTSpecial Weather StatementFFCDade, Walker41 min
Aug 1, 6:26 PM EDTSpecial Weather StatementFFCHenry, Rockdale49 min
Aug 1, 6:49 PM EDTSevere Thunderstorm WarningFFCChattooga, Walker41 min
Aug 1, 7:23 PM EDTSevere Thunderstorm WarningFFCChattooga, Walker52 min
Aug 1, 7:39 PM EDTSpecial Weather StatementFFCFannin, Towns, Union51 min

Nearby

Special Weather Statements in Georgia, 2012Every special weather statement in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.