Tornado Watch 402

Issued

Jun 16, 2007, 5:58 PM MDT (23:58 UTC)

Expired

Jun 16, 2007, 10:20 PM MDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

Counties Butte County, SD, Custer County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD

The Rapid City radar (KUDX), 96 km from the middle of the area, began a volume at 00:03 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.

Two or more tornadoes

50%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

60%

One or more hailstones of 2 inches or more

50%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 1166Jun 16, 2:53 PM MDT
• Mesoscale Discussion 1170Jun 16, 9:38 PM MDT

000
WWUS20 KWNS 162357
SEL2  
SPC WW 162357
SDZ000-170800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 402
NWS STORM PREDICTION CENTER NORMAN OK
555 PM MDT SAT JUN 16 2007

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

       WESTERN SOUTH DAKOTA

EFFECTIVE THIS SATURDAY AFTERNOON AND SUNDAY MORNING FROM 555 PM
UNTIL 200 AM MDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHEAST OF BUFFALO
SOUTH DAKOTA TO 40 MILES SOUTH SOUTHEAST OF RAPID CITY SOUTH
DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

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...CONTINUE...WW 400...WW 401...

DISCUSSION...THUNDERSTORMS WILL SPREAD EWD FROM NE WY INTO WRN SD
THE NEXT FEW HOURS...AND ADDITIONAL DEVELOPMENT WILL BE POSSIBLE
ALONG A BOUNDARY MOVING SLOWLY NWD ACROSS SW SD.  THE CAP HAS BEEN
WEAKENING GRADUALLY WITH WARMING SURFACE TEMPERATURES...AND BOUNDARY
LAYER DEWPOINTS HAVE NOW INCREASED INTO THE LOW-MID 60S ACROSS WRN
SD.  THE COMBINATION OF MLCAPE VALUES OF 2000-3000 J/KG...EFFECTIVE
BULK SHEAR NEAR 50 KT...AND EFFECTIVE SRH NEAR 300 M2/S2 WILL
SUPPORT SUPERCELLS CAPABLE OF PRODUCING TORNADOES...LARGE HAIL...AND
DAMAGING WINDS INTO TONIGHT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 27030.


...THOMPSON

Tornado Watches in South Dakota, 2007Every tornado watch in 2007

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.