Alert archive / South Dakota / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 615

August 16, 200230 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 16, 2002, 8:25 PM CDT for 30 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Aug 16, 2002, 8:25 PM CDT (01:25 UTC)
Expired: Aug 17, 2002, 2:00 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 30 counties

Aurora County, SD, Beadle County, SD, Brookings County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Deuel County, SD, Douglas County, SD, Faulk County, SD, Grant County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hutchinson County, SD, Hyde County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Spink County, SD, Turner County, SD

The radar

The Sioux Falls radar (KFSD), 115 km from the middle of the area, began a volume at 01:26 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

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

Issued	Product	Office	Counties	Lasted
Aug 16, 11:37 PM CDT	Severe Thunderstorm Warning	ABR	Deuel	23 min

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 1.4 hours before the alert went out and 83 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: 134 J/kg
Mixed-layer CIN: -501 J/kg
Mixed-layer LCL: 802 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 272 m²/s²
0-3 km storm-relative helicity: 424 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.6

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 170127
SEL5  
SPC WW 170125
IAZ000-MNZ000-SDZ000-170700-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 615
STORM PREDICTION CENTER NORMAN OK
825 PM CDT FRI AUG 16 2002

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

   EXTREME NORTHWEST IOWA                               
   EXTREME SOUTHWEST MINNESOTA                          
   EASTERN SOUTH DAKOTA                       

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 825 PM UNTIL
200 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 85 STATUTE MILES
EAST AND WEST OF A LINE FROM 50 MILES WEST NORTHWEST OF WATERTOWN
SOUTH DAKOTA TO 50 MILES SOUTH OF MITCHELL SOUTH DAKOTA.

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...  CONTINUE...WW 613...WW 614...

DISCUSSION...LINE OF SEVERE STORMS WITH EMBEDDED BOW ECHOES IS
TRACKING SEWD NEAR 50 KT.  QUESTION IS IF THE LINE WILL BEGIN
DEVELOPING SWD AS IT MOVES INTO THE NERN QUADRANT OF SFC LOW WHERE
40 KT LOW LEVEL JET WILL ENHANCE WARM ADVECTION.  60 KT MID LEVEL
JET IS STREAKING ACROSS SD ATTM CREATING VERY STRONG VERTICAL SHEAR
PROFILES FAVORABLE FOR SUPERCELLS/BOW ECHOES.

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 28045.


...MCCARTHY

451,0962 430,0962 430,0994 451,0995

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 16, 10:00 PM CDT	Severe Thunderstorm Watch	SPC	Codington, Grant, Roberts	5 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2002 Every 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; radar from the NEXRAD Level II archive.