Alert archive / Arkansas / Tornado Watches in 2002

Tornado Watch 782

December 18, 200218 counties in Arkansas; 18 counties in Missouri; Latimer County, LeFlore County, Sequoyah County, Oklahoma

The Storm Prediction Center issued this tornado watch at Dec 18, 2002, 7:20 AM CST for 18 counties in Arkansas; 18 counties in Missouri; Latimer County, LeFlore County, Sequoyah County, Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Dec 18, 2002, 7:20 AM CST (13:20 UTC)
Expired
Dec 18, 2002, 1:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
All 39 counties

Baxter County, AR, Boone County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Fulton County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Christian County, MO, Dent County, MO, Douglas County, MO, Howell County, MO, Iron County, MO, Laclede County, MO, Oregon County, MO, Ozark County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Saint Francois County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO, Latimer County, OK, LeFlore County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 116 km from the middle of the area, began a volume at 13:22 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

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

IssuedProductOfficeCountiesLasted
Dec 18, 9:04 AM CSTSevere Thunderstorm WarningSGFWebster, Wright41 min
Dec 18, 9:34 AM CSTSevere Thunderstorm WarningLZKBoone31 min

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 1.3 hours before the alert went out and 106 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, Springfield, MO at 12:00Z on 2002-12-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 894 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, Springfield, MO at 12:00Z on 2002-12-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 425 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
894 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
549 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
425 m²/s²
0-3 km storm-relative helicity
449 m²/s²
Significant tornado parameter
2.4
Supercell composite
8.2

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 181325
SEL2  
SPC WW 181320
ARZ000-MOZ000-OKZ000-181900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 782
STORM PREDICTION CENTER NORMAN OK
720 AM CST WED DEC 18 2002

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

   NORTHWEST AND NORTH-CENTRAL ARKANSAS                           
   SOUTHERN MISSOURI                           
   EAST-CENTRAL OKLAHOMA                           

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 720 AM UNTIL
100 PM CST.

TORNADOES...HAIL TO 2 INCHES 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 40 MILES SOUTH OF FORT SMITH ARKANSAS TO 40 MILES
EAST NORTHEAST OF FORT LEONARD WOOD MISSOURI.

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 SEVERE
THUNDERSTORM WATCH NUMBER 780.  WATCH NUMBER 780 WILL NOT BE IN
EFFECT AFTER 720 AM CST.  CONTINUE...WW 781...

DISCUSSION... APPEARS SUBTLE SHORTWAVE TROUGH EJECTING NEWD ACROSS
OK IN WV IMAGERY WILL SUPPORT FURTHER CONVECTION OVER THIS REGION
DURING THE NEXT SEVERAL HOURS. COMBINATION OF SHEAR AND INSTABILITY
REMAIN FAVORABLE FOR TORNADIC SUPERCELLS...WITH SR-HELICITY IN
EXCESS OF 300-400 M2/S2 AND SBCAPES AROUND 1000 J/KG.  12Z AT SGF
INDICATED VERY LITTLE CAPPING...ONCE TEMPERATURES WARM INTO THE MID
60S AND DEW POINTS HOLD AROUND 60F.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24045.


...EVANS

375,0901 344,0931 344,0953 375,0923

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 17, 7:35 PM CSTTornado WatchSPCBenton, Boone, Carroll, Madison, Marion, Newton and 1 more5 hr
Dec 17, 10:40 PM CSTTornado WatchSPCBenton, Carroll, Washington5 hr
Dec 18, 3:30 AM CSTTornado WatchSPCBenton5 hr
Dec 18, 1:10 PM CSTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 26 more8 hr
Dec 18, 2:30 PM CSTTornado WatchSPCBaxter, Clay, Cleburne, Conway, Craighead, Crittenden and 18 more7 hr
Dec 18, 5:50 PM CSTTornado WatchSPCChicot, Crittenden, Desha, Lee, Mississippi, Phillips and 1 more3 hr
Dec 18, 2:15 AM CSTSevere Thunderstorm WatchSPCAdair, Bates, Buchanan, Caldwell, Carroll, Cass and 29 more6 hr
Dec 18, 9:30 AM CSTTornado WatchSPCAdair, Audrain, Barton, Benton, Boone, Callaway and 33 more6 hr
Dec 18, 4:35 PM CSTTornado WatchSPCCrawford, Dent, Franklin, Gasconade, Jefferson, Laclede and 14 more5 hr

Nearby

Tornado Watches in Arkansas, 2002Tornado Watches in Missouri, 2002Tornado Watches in Oklahoma, 2002Every 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.