Alert archive / South Dakota / Severe Thunderstorm Watches in 2003

Severe Thunderstorm Watch 855

August 9, 200315 counties in Nebraska; 21 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 9, 2003, 5:15 PM CDT for 15 counties in Nebraska; 21 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Aug 9, 2003, 5:15 PM CDT (22:15 UTC)
Expired: Aug 9, 2003, 11:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 36 counties

Antelope County, NE, Boone County, NE, Boyd County, NE, Cedar County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Knox County, NE, Madison County, NE, Pierce County, NE, Platte County, NE, Rock County, NE, Stanton County, NE, Valley County, NE, Wheeler County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, McCook County, SD, Miner County, SD, Sanborn County, SD, Turner County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 170 km from the middle of the area, began a volume at 22:19 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

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

Issued	Product	Office	Counties	Lasted
Aug 9, 5:19 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	41 min
Aug 9, 5:59 PM CDT	Severe Thunderstorm Warning	FSD	Beadle	31 min
Aug 9, 9:33 PM CDT	Severe Thunderstorm Warning	OAX	Knox	27 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

Aberdeen, SD (KABR), launched 12:00Z, 10.3 hours before the alert went out and 232 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: 144 J/kg
Mixed-layer CIN: -488 J/kg
Mixed-layer LCL: 1174 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 187 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

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

104 
WWUS20 KWNS 092215
SEL5  
SPC WW 092215
NEZ000-SDZ000-100400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 855 
NWS STORM PREDICTION CENTER NORMAN OK 
515 PM CDT SAT AUG 9 2003

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

       NORTHEAST NEBRASKA
       SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 515 PM UNTIL
1100 PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 60 STATUTE MILES
EAST AND WEST OF A LINE FROM 25 MILES NORTH OF HURON SOUTH DAKOTA
TO 45 MILES EAST SOUTHEAST OF BURWELL NEBRASKA.

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.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 853. WATCH NUMBER 853 WILL NOT BE
IN EFFECT AFTER 515 PM CDT. CONTINUE...WW 854...


DISCUSSION...CLUSTERS OF SEVERE THUNDERSTORMS OVER ERN SD WILL
CONTINUE TO DEVELOP MAINLY SWD INTO THE AXIS OF THE MOST UNSTABLE
AIR MASS.  WITH MLCAPES AOA 2500 J/KG AND FAVORABLE DEEP LAYER
SHEAR...SEVERE POTENTIAL INCLUDING DAMAGING DOWNBURST WINDS WILL
CONTINUE UNTIL LATER THIS EVENING.

AVIATION...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 550. MEAN STORM
MOTION VECTOR 34025.


...HALES

444,0970 413,0971 413,0993 444,0992

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 9, 2:52 PM CDT	Mesoscale Discussion	SPC	Arthur, Box Butte, Cherry, Cheyenne, Dawes, Deuel and 10 more	113 min
Aug 9, 3:35 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Brown, Cherry, Deuel, Garden and 9 more	5 hr
Aug 9, 11:02 AM CDT	Mesoscale Discussion	SPC	Brown, Campbell, Dewey, Edmunds, Faulk, McPherson and 4 more	118 min
Aug 9, 1:55 PM CDT	Severe Thunderstorm Watch	SPC	Aurora, Beadle, Bennett, Brookings, Brown, Brule and 29 more	5 hr
Aug 9, 3:38 PM CDT	Mesoscale Discussion	SPC	Aurora, Beadle, Bennett, Brookings, Brown, Brule and 28 more	2 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2003 Severe Thunderstorm Watches in Nebraska, 2003 Every severe thunderstorm watch in 2003

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.