

183 

WWUS20 KWNS 200425

SEL5

SPC WW 200425

MNZ000-SDZ000-201000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 415

NWS STORM PREDICTION CENTER NORMAN OK

1120 PM CDT TUE JUN 19 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME WEST CENTRAL MINNESOTA

       CENTRAL AND EASTERN SOUTH DAKOTA



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 1120 PM

UNTIL 500 AM 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 APPROXIMATELY ALONG AND 45

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES SOUTH OF

ORTONVILLE MINNESOTA TO 25 MILES SOUTHWEST OF PIERRE SOUTH

DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 412...WW 413...WW 414...



DISCUSSION...EARLIER CONVECTION ALONG SFC FRONT ACROSS NEB AND SERN

SD REMAINED ISOLATED AND POORLY ORGANIZED MOST LIKELY UNDER THE

INFLUENCE OF STRONG INHIBITION AND LACK OF STRONGER LARGE SCALE

ASCENT. LIFT ACROSS THE DEEPER FRONTAL ZONE HAS NOW TRANSITIONED

WELL TO THE NORTH OF THE SURFACE BOUNDARY AND AHEAD OF STRONGER

LARGE SCALE FORCING SPREADING EAST FROM WY. NOCTURNAL INCREASE IN

LOW LEVEL MASS TRANSPORT ON THE NOSE OF THE PLAINS LOW LEVEL JET

WILL ALSO SUSTAIN ASCENT ACROSS THE FRONTAL ZONE TONIGHT. RECENT

DEVELOPMENT IS OCCURRING ON THE SRN EDGE OF STRONGER SWLY FLOW ALOFT

WHERE EFFECTIVE SHEAR SHOULD PROMOTE STORM PERSISTENCE AND SOME

ORGANIZATION. WITH AIR PARCELS ORIGINATING FROM THE HOT AND MOIST

UNSTABLE AIR RESIDING TO THE SOUTH ACROSS THE CNTRL

PLAINS...RESULTING STORMS SHOULD BE CAPABLE OF PRODUCING LARGE HAIL

AND OCCASIONAL STRONG TO DAMAGING WIND GUSTS.



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 450. MEAN STORM

MOTION VECTOR 21020.





...CARBIN

