Alert archive / Kansas / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 621

August 18, 200244 counties in Kansas

The Storm Prediction Center issued this severe thunderstorm watch at Aug 18, 2002, 7:30 PM CDT for 44 counties in Kansas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 18, 2002, 7:30 PM CDT (00:30 UTC)
Expired
Aug 19, 2002, 1:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 44 counties

Anderson County, KS, Atchison County, KS, Barton County, KS, Brown County, KS, Chase County, KS, Clay County, KS, Cloud County, KS, Coffey County, KS, Dickinson County, KS, Douglas County, KS, Ellis County, KS, Ellsworth County, KS, Franklin County, KS, Geary County, KS, Graham County, KS, Hodgeman County, KS, Jackson County, KS, Jefferson County, KS, Jewell County, KS, Lincoln County, KS, Lyon County, KS, Marion County, KS, Marshall County, KS, McPherson County, KS, Mitchell County, KS, Morris County, KS, Nemaha County, KS, Ness County, KS, Osage County, KS, Osborne County, KS, Ottawa County, KS, Pawnee County, KS, Pottawatomie County, KS, Republic County, KS, Rice County, KS, Riley County, KS, Rooks County, KS, Rush County, KS, Russell County, KS, Saline County, KS, Shawnee County, KS, Trego County, KS, Wabaunsee County, KS, Washington County, KS

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 18, 8:43 PM CDTSevere Thunderstorm WarningGLDGraham62 min
Aug 18, 8:46 PM CDTSevere Thunderstorm WarningDDCTrego59 min
Aug 18, 9:35 PM CDTSevere Thunderstorm WarningDDCEllis55 min
Aug 18, 9:50 PM CDTSevere Thunderstorm WarningDDCTrego40 min

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 0.5 hours before the alert went out and 219 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, Topeka, KS at 00:00Z on 2002-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4282 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, Topeka, KS at 00:00Z on 2002-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
4282 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1435 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
213 m²/s²
Significant tornado parameter
1.8
Supercell composite
19.3

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 190032
SEL1  
SPC WW 190030
KSZ000-190600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 621
STORM PREDICTION CENTER NORMAN OK
730 PM CDT SUN AUG 18 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   CENTRAL AND EASTERN KANSAS                             

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 730 PM UNTIL
100 AM CDT.

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

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 60 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH SOUTHWEST OF HILL
CITY KANSAS TO 20 MILES EAST OF TOPEKA KANSAS.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.


DISCUSSION...AIR MASS OVER MUCH OF CENTRAL AND EASTERN KANSAS IS
VERY UNSTABLE WITH MIXED LAYER CAPE FROM 3000 TO 4500 J/KG.  MODEL
DATA INDCIATES STRONG UVVS OVER THIS AREA NEXT HOUR OR SO ENOUGH TO
POSSIBLY BREAK 1-2 DEG C CAP ACROSS THE AREA. LOW LEVEL JET OF 30-
40 KT IS ALSO EXPECTED TO ENHANCE ASCENT FOR DEVELOPMENT.  LOW/MID
LEVEL SHEAR VECTOR IS 25-30 KT ATTM WHICH MAY BE SUFFICIENT FOR
SUPERCELLS.

AVIATION...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 28035.


...MCCARTHY

394,1000 395,0951 381,0951 375,1000

Nearby

Severe Thunderstorm Watches in Kansas, 2002Every severe thunderstorm 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.