Alert archive / Mississippi / Tornado Watches in 2004

Tornado Watch 855

October 18, 200418 counties in Arkansas; 21 counties in Mississippi; 4 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Oct 18, 2004, 9:45 AM CDT for 18 counties in Arkansas; 21 counties in Mississippi; 4 counties in Tennessee. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Oct 18, 2004, 9:45 AM CDT (14:45 UTC)
Expired
Oct 18, 2004, 3:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 43 counties

Arkansas County, AR, Calhoun County, AR, Cleveland County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Fayette County, TN, Hardeman County, TN, McNairy County, TN, Shelby County, TN

The radar

The Little Rock radar (KLZK), 117 km from the middle of the area, began a volume at 14:47 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

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

IssuedProductOfficeCountiesLasted
Oct 18, 9:51 AM CDTTornado WarningLZKLonoke39 min
Oct 18, 9:57 AM CDTTornado WarningLZKPulaski18 min
Oct 18, 10:26 AM CDTTornado WarningLZKLonoke, Prairie64 min
Oct 18, 10:53 AM CDTFlash Flood WarningLZKLonoke2 hr
Oct 18, 11:14 AM CDTFlash Flood WarningLZKPrairie2 hr
Oct 18, 11:19 AM CDTTornado WarningLZKMonroe56 min
Oct 18, 11:30 AM CDTSevere Thunderstorm WarningLZKArkansas, Lonoke, Prairie45 min
Oct 18, 11:36 AM CDTSevere Thunderstorm WarningMEGShelby39 min
Oct 18, 11:56 AM CDTFlash Flood WarningMEGFayette94 min
Oct 18, 12:09 PM CDTFlash Flood WarningMEGShelby96 min
Oct 18, 12:13 PM CDTSevere Thunderstorm WarningMEGFayette, Shelby47 min
Oct 18, 12:16 PM CDTFlash Flood WarningMEGHardeman89 min
Oct 18, 12:17 PM CDTTornado WarningMEGPhillips43 min
Oct 18, 12:40 PM CDTTornado WarningMEGFayette35 min
Oct 18, 1:09 PM CDTSevere Thunderstorm WarningMEGPanola, Tate, Tunica36 min
Oct 18, 2:27 PM CDTSevere Thunderstorm WarningMEGBenton, Tippah33 min
Oct 18, 2:57 PM CDTSevere Thunderstorm WarningMEGAlcorn48 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

Little Rock, AR (KLZK), launched 12:00Z, 2.8 hours before the alert went out and 105 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, Little Rock, AR at 12:00Z on 2004-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1504 joules per kilogram.LCLLFCEL10008507005003002001001 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, Little Rock, AR at 12:00Z on 2004-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 390 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
1504 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
520 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
390 m²/s²
0-3 km storm-relative helicity
482 m²/s²
Significant tornado parameter
3.3
Supercell composite
16.6

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 181443
SEL5  
SPC WW 181445
ARZ000-MSZ000-TNZ000-182000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 855
NWS STORM PREDICTION CENTER NORMAN OK
945 AM CDT MON OCT 18 2004

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

       SOUTHERN AND EASTERN ARKANSAS
       NORTHERN MISSISSIPPI
       SOUTHWESTERN TENNESSEE

EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 945 AM UNTIL 300
PM CDT.

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 50 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 55 MILES WEST OF PINE BLUFF ARKANSAS TO 40
MILES NORTHEAST OF TUPELO MISSISSIPPI.

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.

DISCUSSION...VERY STRONG SHEAR PROFILES ACROSS AREA AS THUNDERSTORMS
CONTINUE TO DEVELOP ALONG AN ENE-WSW AXIS ERN AR AND WRN TN. WITH
VERY MOIST/UNSTABLE AIR MASS FEEDING NEWD ON 40-50 KT LLJ POTENTIAL
FOR TORNADIC SUPERCELLS WILL INCREASE WATCH AREA AS MID LEVEL TROUGH
MOVES EWD ACROSS MID MS VALLEY.

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 550.
MEAN STORM MOTION VECTOR 24040.


...HALES

345,0925 352,0881 335,0881 332,0925

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 17, 11:30 PM CDTSevere Thunderstorm WatchSPCBaxter, Clay, Fulton, Greene, Marion, Randolph and 1 more6 hr
Oct 18, 2:19 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clark, Clay and 42 more56 min
Oct 18, 4:40 AM CDTMesoscale DiscussionSPCClay, Greene, Randolph, Sharp35 min
Oct 18, 7:44 AM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 43 more61 min
Oct 18, 11:29 AM CDTMesoscale DiscussionSPCArkansas, Calhoun, Cleveland, Dallas, Desha, Drew and 12 more91 min
Oct 18, 2:18 PM CDTMesoscale DiscussionSPCArkansas, Calhoun, Cleveland, Dallas, Desha, Drew and 12 more57 min
Oct 18, 4:05 PM CDTTornado WatchSPCBaxter, Clay, Cleburne, Craighead, Crittenden, Cross and 15 more5 hr
Oct 18, 5:21 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more114 min
Oct 18, 5:50 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 20 more5 hr
Oct 18, 1:55 PM CDTMesoscale DiscussionSPCStewart95 min
Oct 18, 3:20 PM CDTTornado WatchSPCFranklin, Giles, Lincoln5 hr
Oct 18, 6:02 PM CDTMesoscale DiscussionSPCFranklin, Giles, Lawrence, Lincoln, Moore, Wayne88 min

Nearby

Tornado Watches in Mississippi, 2004Tornado Watches in Arkansas, 2004Tornado Watches in Tennessee, 2004Every tornado watch in 2004

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.