Alert archive / Georgia / Tornado Watches in 2012

Tornado Watch 12

January 23, 201230 counties in Georgia

The Storm Prediction Center issued this tornado watch at Jan 23, 2012, 8:49 AM EST for 30 counties in Georgia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jan 23, 2012, 8:49 AM EST (13:49 UTC)
Expired
Jan 23, 2012, 1:38 PM EST
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 30 counties

Bibb County, GA, Carroll County, GA, Chattahoochee County, GA, Coweta County, GA, Crawford County, GA, Crisp County, GA, Dooly County, GA, Harris County, GA, Heard County, GA, Houston County, GA, Lamar County, GA, Lee County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Muscogee County, GA, Peach County, GA, Pike County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taylor County, GA, Terrell County, GA, Troup County, GA, Upson County, GA, Webster County, GA

The radar

The Atlanta radar (KFFC), 72 km from the middle of the area, began a volume at 13:52 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
40%

Warnings issued inside it

1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jan 23, 9:40 AM ESTSevere Thunderstorm WarningFFCHeard, Troup50 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 1.8 hours before the alert went out and 73 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 2012-01-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-01-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 492 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
463 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
492 m²/s²
0-3 km storm-relative helicity
722 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.

148 
WWUS20 KWNS 231355
SEL2
SPC WW 231355
GAZ000-232100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 12
NWS STORM PREDICTION CENTER NORMAN OK
850 AM EST MON JAN 23 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       WEST CENTRAL AND SOUTHWEST GEORGIA

EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 850 AM UNTIL 400
PM EST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EITHER SIDE OF A LINE FROM 15 MILES WEST SOUTHWEST OF
COLUMBUS GEORGIA TO 5 MILES NORTHEAST OF MACON GEORGIA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 11...

DISCUSSION...A SMALL AREA OF W CNTRL GA MAY HAVE POTENTIAL FOR ISOLD
TORNADOES LATER THIS MORNING THROUGH EARLY THIS AFTN AS REGION
REMAINS BENEATH SRN FRINGE OF STRONG WIND FIELD ASSOCIATED WITH
DEPARTING NEGATIVE TILT UPR TROUGH.  THE AREA OF GREATEST RISK FOR
TORNADOES SHOULD FOCUS BETWEEN EXISTING SW-NE BAND OF STORMS NOW
NEARING MGM...AND CONFLUENCE BAND MARKING ERN EDGE OF RICH MOISTURE
RETURN ATTM EXTENDING SSW FROM NEAR CSG.  THE STORMS SHOULD CONTINUE
TO MOVE/DEVELOP ENEWD AS THE MOISTURE DISCONTINUITY DRIFTS SLOWLY E
WITH TIME.  MODEST SFC HEATING MAY COMPENSATE FOR DIMINISHING WIND
FIELD AND FORCING FOR ASCENT TO MAINTAIN AT LEAST A CONDITIONAL SVR
RISK S AND W OF WEDGE AIR MASS FIRMLY ENTRENCHED OVER CNTRL/ERN GA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 25040.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 23, 2:25 AM ESTMesoscale DiscussionSPCCatoosa, Chattooga, Dade, Walker2 hr
Jan 23, 3:44 AM ESTTornado WatchSPCBartow, Carroll, Catoosa, Chattooga, Dade, Floyd and 9 more9 hr
Jan 23, 5:02 AM ESTMesoscale DiscussionSPCCatoosa, Chattooga, Dade, Floyd, Gordon, Haralson and 3 more118 min
Jan 23, 7:38 AM ESTMesoscale DiscussionSPCCarroll, Coweta, Douglas, Floyd, Haralson, Harris and 7 more97 min
Jan 23, 12:30 PM ESTMesoscale DiscussionSPCBibb, Bleckley, Chattahoochee, Crawford, Dooly, Harris and 14 more2 hr

Nearby

Tornado Watches in Georgia, 2012Every tornado watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.