Alert archive / Mississippi / Tornado Watches in 2002

Tornado Watch 789

December 18, 20025 counties in Arkansas; 11 counties in Mississippi; 11 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Dec 18, 2002, 9:05 PM CST for 5 counties in Arkansas; 11 counties in Mississippi; 11 counties in Tennessee. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 18, 2002, 9:05 PM CST (03:05 UTC)
Expired: Dec 19, 2002, 3:00 AM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 27 counties

Crittenden County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, St. Francis County, AR, Benton County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Chester County, TN, Decatur County, TN, Fayette County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Shelby County, TN, Tipton County, TN

The radar

The Memphis radar (KNQA), 64 km from the middle of the area, began a volume at 03:09 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 18, 9:13 PM CST	Tornado Warning	MEG	St. Francis	47 min
Dec 18, 9:16 PM CST	Tornado Warning	MEG	Lee, Phillips	59 min
Dec 18, 10:01 PM CST	Severe Thunderstorm Warning	MEG	Crittenden	59 min
Dec 18, 10:39 PM CST	Flash Flood Warning	MEG	Shelby, Tipton	3 hr
Dec 19, 12:24 AM CST	Severe Thunderstorm Warning	MEG	DeSoto, Tate	36 min
Dec 19, 1:59 AM CST	Severe Thunderstorm Warning	MEG	Panola, Tate	31 min

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 3.1 hours before the alert went out and 10 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 605 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: -131 m²/s²
0-3 km storm-relative helicity: -27 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.

000 
WWUS20 KWNS 190304
SEL9  
SPC WW 190305
ARZ000-MSZ000-TNZ000-190900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 789
STORM PREDICTION CENTER NORMAN OK
905 PM CST WED DEC 18 2002

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

   EASTERN ARKANSAS                           
   NORTHERN MISSISSIPPI                        
   WEST TENNESSEE                          

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 905 PM
UNTIL 300 AM CST.

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 ALONG AND 65 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES WEST SOUTHWEST OF OXFORD MISSISSIPPI TO 15
MILES NORTH NORTHWEST OF JACKSON TENNESSEE.

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 785...TORNADO WATCH NUMBER 787.  WATCH NUMBER 785...787 WILL
NOT BE IN EFFECT AFTER 905 PM CST.  CONTINUE...WW 784...

DISCUSSION...CONVECTIVE BAND IN ERN AR EXPECTED TO PROGRESS E
ACROSS W TN...WITH CONTINUING POTENTIAL FOR EMBEDDED SUPERCELLS/
POSSIBLE ISOLATED TORNADOES.  ADVECTION OF RELATIVELY DRY LOW LEVEL
AIR FROM THE SSE SHOULD MITIGATE STRENGTH OF ACTIVITY WITH
TIME...DESPITE PRESENCE OF STRONG /60 KT/ DEEP SHEAR. 

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 400. 
MEAN STORM MOTION VECTOR 24040.

...CORFIDI

354,0875 340,0891 340,0912 354,0901

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 18, 8:55 PM CST	Tornado Watch	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Columbia and 8 more	6 hr
Dec 19, 2:25 AM CST	Tornado Watch	SPC	Ashley, Bradley, Chicot, Union	8 hr
Dec 19, 6:30 AM CST	Tornado Watch	SPC	Adams, Amite, Attala, Carroll, Choctaw, Claiborne and 37 more	6 hr
Dec 19, 9:35 AM CST	Tornado Watch	SPC	Clarke, Forrest, George, Greene, Hancock, Harrison and 9 more	5 hr
Dec 19, 11:40 AM CST	Tornado Watch	SPC	Choctaw, Clarke, Covington, Forrest, George, Greene and 26 more	6 hr

Nearby

Tornado Watches in Mississippi, 2002 Tornado Watches in Tennessee, 2002 Tornado Watches in Arkansas, 2002 Every tornado watch in 2002

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.