Alert archive / Mississippi / Tornado Watches in 1999

Tornado Watch 21

January 21, 1999Chicot County, Arkansas; 31 counties in Mississippi; 24 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Jan 21, 1999, 4:30 PM CST for Chicot County, Arkansas; 31 counties in Mississippi; 24 counties in Tennessee. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jan 21, 1999, 4:30 PM CST (22:30 UTC)
Expired: Jan 21, 1999, 10:00 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 56 counties

Chicot County, AR, Alcorn County, MS, Attala County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Marshall County, MS, Montgomery County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Washington County, MS, Webster County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Madison County, TN, McNairy County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Wayne County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 104 km from the middle of the area, began a volume at 22:30 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

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

Issued	Product	Office	Counties	Lasted
Jan 21, 4:53 PM CST	Severe Thunderstorm Warning	MEG	Tate	32 min
Jan 21, 5:04 PM CST	Severe Thunderstorm Warning	JAN	Bolivar	31 min
Jan 21, 7:16 PM CST	Tornado Warning	JAN	Ashley, Chicot	49 min
Jan 21, 7:53 PM CST	Tornado Warning	JAN	Bolivar, Washington	62 min
Jan 21, 8:06 PM CST	Tornado Warning	JAN	Chicot	49 min
Jan 21, 8:53 PM CST	Severe Thunderstorm Warning	JAN	Washington	47 min
Jan 21, 9:17 PM CST	Severe Thunderstorm Warning	JAN	Bolivar	33 min
Jan 21, 9:35 PM CST	Tornado Warning	JAN	Sunflower	50 min
Jan 21, 9:40 PM CST	Severe Thunderstorm Warning	JAN	Chicot	35 min

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 10.5 hours before the alert went out and 53 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: 701 J/kg
Mixed-layer CIN: -198 J/kg
Mixed-layer LCL: 594 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 258 m²/s²
0-3 km storm-relative helicity: 227 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

999 
WWUS9 KMKC 212153
SEL1  
MKC WW 212153
MSZ000-TNZ000-220400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 21
STORM PREDICTION CENTER NORMAN OK
353 PM CST THU JAN 21 1999

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

   NORHTERN MISSISSIPPI                        
   WESTERN TENNESSEE                          

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 430 PM UNTIL
1000 PM CST.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 60 STATUTE MILES EAST AND WEST
OF A LINE FROM 40 MILES SOUTHEAST OF GREENVILLE MISSISSIPPI TO 85
MILES NORTHEAST 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...  CONTINUE...WW 18...WW 19...WW 20...

DISCUSSION...SEVERE THUNDERSTORMS DEVELOPING NEAR MS RIVER WILL
CONTINUE TO INTENSIFY AND MOVE INTO WW.  AIRMASS AND WIND SHEAR
PROFILES FAVORABLE FOR ROTATING STORMS AND TORNADOS.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 23040.


...HALES

330,0913 362,0885 362,0864 330,0892

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 21, 2:30 PM CST	Tornado Watch	SPC	Arkansas, Ashley, Baxter, Bradley, Calhoun, Clark and 54 more	7 hr
Jan 21, 5:00 PM CST	Tornado Watch	SPC	Benton, Boone, Carroll, Crawford, Franklin, Howard and 12 more	5 hr
Jan 21, 4:30 PM CST	Tornado Watch	SPC	Henry, Obion, Stewart, Weakley	6 hr

Nearby

Tornado Watches in Mississippi, 1999 Tornado Watches in Tennessee, 1999 Tornado Watches in Arkansas, 1999 Every tornado watch in 1999

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.