Alert archive / Georgia / Tornado Watches in 2007

Tornado Watch 146

April 15, 200720 counties in Georgia

The Storm Prediction Center issued this tornado watch at Apr 15, 2007, 5:57 AM EDT for 20 counties in Georgia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2007, 5:57 AM EDT (09:57 UTC)
Expired
Apr 15, 2007, 11:00 AM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Appling County, GA, Atkinson County, GA, Bacon County, GA, Bryan County, GA, Bulloch County, GA, Candler County, GA, Chatham County, GA, Coffee County, GA, Effingham County, GA, Evans County, GA, Jeff Davis County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Pierce County, GA, Screven County, GA, Tattnall County, GA, Ware County, GA, Wayne County, GA

The radar

The Charleston,SC radar (KCLX), 130 km from the middle of the area, began a volume at 09:59 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
10%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
30%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 15, 6:59 AM EDTSevere Thunderstorm WarningJAXCharlton, Ware31 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

Jacksonville, FL (KJAX), launched 00:00Z, 10.0 hours before the alert went out and 177 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, Jacksonville, FL at 00:00Z on 2007-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 344 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jacksonville, FL at 00:00Z on 2007-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 square meters per square second.1939587897Sfc1 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
344 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
1113 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 150957
SEL6  
SPC WW 150957
GAZ000-CWZ000-151500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 146
NWS STORM PREDICTION CENTER NORMAN OK
600 AM EDT SUN APR 15 2007

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

       SOUTHEAST GEORGIA
       COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING FROM 600 AM UNTIL 1100 AM EDT.

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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF VIDALIA
GEORGIA TO 15 MILES EAST SOUTHEAST OF WAYCROSS GEORGIA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU6).

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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 144. WATCH NUMBER 144 WILL NOT BE IN EFFECT AFTER
600 AM EDT. CONTINUE...WW 145...

DISCUSSION...BROKEN BAND OF STORMS ALONG COLD FRONT WILL MOVE FROM
CENTRAL INTO SE GA DURING THE NEXT FEW HOURS.  THOUGH INSTABILITY IS
LIMITED...VERTICAL SHEAR REMAINS SUFFICIENT FOR SUPERCELLS AND THE
POSSIBILITY OF A TORNADO OR TWO...AS WELL AS A FEW DAMAGING GUSTS.

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 24040.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 8:09 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 93 more2 hr
Apr 14, 10:10 PM EDTMesoscale DiscussionSPCBurke, Columbia, Jenkins, Lincoln, Richmond, Screven95 min
Apr 14, 11:45 PM EDTTornado WatchSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 57 more6 hr
Apr 15, 2:01 AM EDTTornado WatchSPCBurke7 hr
Apr 15, 3:57 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 39 more93 min
Apr 15, 10:20 AM EDTMesoscale DiscussionSPCChatham55 min
Apr 15, 3:33 AM EDTMesoscale DiscussionSPCChesterfield, Darlington, Fairfield, Kershaw, Lancaster, Lee and 3 more87 min
Apr 15, 7:39 AM EDTMesoscale DiscussionSPCBamberg, Berkeley, Calhoun, Charleston, Chesterfield, Clarendon and 13 more66 min
Apr 15, 8:08 AM EDTTornado WatchSPCAllendale, Bamberg, Barnwell, Beaufort, Berkeley, Calhoun and 17 more7 hr
Apr 15, 11:15 AM EDTMesoscale DiscussionSPCBerkeley, Charleston, Dillon, Dorchester, Florence, Georgetown and 3 more2 hr
Apr 15, 12:19 PM EDTMesoscale DiscussionSPCChester, Lancaster, York86 min

Nearby

Tornado Watches in Georgia, 2007Every tornado watch in 2007

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.