WWUS20 KWNS 252101
SEL2
SPC WW 252101
SDZ000-260400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 452
NWS STORM PREDICTION CENTER NORMAN OK
400 PM CDT SAT JUL 25 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  CENTRAL AND NORTHERN SOUTH DAKOTA

* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 400 PM UNTIL
  1100 PM CDT.

* PRIMARY THREATS INCLUDE...
  A COUPLE TORNADOES POSSIBLE
  SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 3
    INCHES IN DIAMETER POSSIBLE
  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

SUMMARY...EXPECT DISCRETE STORMS/SUPERCELLS TO CONTINUE TO DEVELOP
ACROSS THE WATCH AREA THROUGH THE EVENING. ACTIVITY WILL BE
SUPPORTED BY STRONG TO LOCALLY EXTREME INSTABILITY AND THE PRESENCE
OF WEAK BACKGROUND ASCENT FOCUSED ALONG THERMAL TROUGH AND WEAK
SURFACE LOW SITUATED ACROSS CENTRAL SD. MAGNITUDE OF INSTABILITY AND
DEEP SHEAR WILL BE MORE THAN ADEQUATE FOR SUPERCELLS. TORNADO THREAT
MAY EVOLVE FROM DISCRETE CELLS NEAR A NARROW AXIS OF BACKED
LOW-LEVEL FLOW LEFT IN THE WAKE OF STORM COMPLEX EARLIER IN THE DAY.
LOWER LFC NEAR THIS WEAK BOUNDARY WILL ALSO SUPPORT THE CHANCE FOR
STRONGER MID TO LOW LEVEL ROTATION TO REACH THE SURFACE.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTHWEST OF PIERRE
SOUTH DAKOTA TO 40 MILES NORTH NORTHEAST OF HURON SOUTH DAKOTA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 451...

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 26020.


...CARBIN