Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 191, NWS Atlanta, GA

April 25, 2011Cherokee County, Forsyth County, Fulton County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Apr 25, 2011, 3:20 PM EDT for Cherokee County, Forsyth County, Fulton County, Georgia. It was in force for 25 min. 1 report 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: Apr 25, 2011, 3:20 PM EDT (19:20 UTC)
Expired: Apr 25, 2011, 3:45 PM EDT
In force: 25 min
Issued by: NWS Atlanta, GA
Area: Storm-based polygon

Counties Cherokee County, GA, Forsyth County, GA, Fulton County, GA

The radar

The Atlanta radar (KFFC), 85 km from the middle of the area, began a volume at 19:21 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

Time	Report	Where	Remark
Apr 25, 3:24 PM EDT	HAIL 1	Sse Sandy Springs, GA	CHATCOMM 911 REPORTED HAIL ABOUT THE SIZE OF QUARTERS HITTING THEIR WINDOWS.

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, 7.3 hours before the alert went out and 82 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: 1169 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 772 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 14 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

966 
WUUS52 KFFC 251920
SVRFFC
GAC057-117-121-251945-
/O.NEW.KFFC.SV.W.0191.110425T1920Z-110425T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
320 PM EDT MON APR 25 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN CHEROKEE COUNTY IN NORTH CENTRAL GEORGIA
  FORSYTH COUNTY IN NORTH CENTRAL GEORGIA
  NORTHEASTERN FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 345 PM EDT

* AT 312 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZED HAIL...AND
  DAMAGING WINDS UP TO 60 MPH.  THIS STORM WAS LOCATED NEAR SANDY
  SPRINGS...MOVING NORTHEAST AT 20 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MOUNTAIN PARK...ALPHARETTA...JOHNS CREEK...MILTON...CUMMING AND
  FREE HOME.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

&&

LAT...LON 3434 8420 3423 8400 3418 8406 3400 8420
      3400 8425 3396 8427 3397 8434 3390 8435
      3393 8442 3398 8437 3401 8440 3404 8440
      3407 8443 3434 8426
TIME...MOT...LOC 1920Z 211DEG 18KT 3401 8434

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 25, 3:19 PM EDT	Severe Thunderstorm Warning	FFC	Lumpkin	41 min
Apr 25, 4:57 PM EDT	Severe Thunderstorm Warning	FFC	Dawson, Forsyth, Gwinnett, Hall	33 min
Apr 25, 7:14 PM EDT	Severe Thunderstorm Warning	FFC	Harris	46 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2011 Every severe thunderstorm warning in 2011

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.