Alert archive / Mississippi / Tornado Watches in 2012

Tornado Watch 592

August 28, 20128 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Aug 28, 2012, 12:56 PM CDT for 8 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 28, 2012, 12:56 PM CDT (17:56 UTC)
Expired
Aug 28, 2012, 7:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt

Counties Covington County, MS, Forrest County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 99 km from the middle of the area, began a volume at 17:56 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
5%
One or more gusts of 65 knots or more
5%
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
20%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 28, 2:32 PM CDTSevere Thunderstorm WarningJANJones43 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

Jackson, MS (KJAN), launched 12:00Z, 5.9 hours before the alert went out and 107 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, Jackson, MS at 12:00Z on 2012-08-28Temperature 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, Jackson, MS at 12:00Z on 2012-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -65 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
0 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-65 m²/s²
0-3 km storm-relative helicity
-4 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.

461 
WWUS20 KWNS 281756
SEL2
SPC WW 281756
MSZ000-290000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 592
NWS STORM PREDICTION CENTER NORMAN OK
1255 PM CDT TUE AUG 28 2012

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

       SOUTHERN MISSISSIPPI

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL
700 PM CDT.

TORNADOES...HAIL TO 0.5 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 35 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 20 MILES EAST SOUTHEAST OF
PINE BELT MISSISSIPPI TO 10 MILES NORTH OF MC COMB MISSISSIPPI.
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 591...

DISCUSSION...W-E ORIENTED BAND OF CONVECTION FROM S OF PIB TO S OF
GZH CONTINUES TO INTENSIFY WHILE DRIFTING SLOWLY NWD WITHIN A VERY
MOIST ENVIRONMENT WITH MLCAPE OF 1000-1500 J/KG.  GIVEN THE OVERLAP
OF THIS INSTABILITY WITH THE NRN PERIPHERY OF STRONGER WIND FIELD
ASSOCIATED WITH T.C. ISAAC...THE THREAT FOR MINI SUPERCELLS CAPABLE
OF TORNADOES SHOULD CONTINUE TO INCREASE THIS AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 10040.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 28, 7:01 AM CDTMesoscale DiscussionSPCSaint Bernard2 hr
Aug 28, 9:46 AM CDTTornado WatchSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more9 hr
Aug 28, 12:37 PM CDTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 10 more83 min
Aug 28, 3:46 PM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more89 min
Aug 28, 5:48 PM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 6 more87 min
Aug 28, 6:47 PM CDTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more21 hr

Nearby

Tornado Watches in Mississippi, 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.