

938 

WWUS20 KWNS 160119

SEL7

SPC WW 160119

IAZ000-KSZ000-MOZ000-NEZ000-160800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 427

NWS STORM PREDICTION CENTER NORMAN OK

815 PM CDT MON JUN 15 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST IOWA

       EXTREME NORTHEAST AND EAST CENTRAL KANSAS

       NORTHWEST AND WEST CENTRAL MISSOURI

       SOUTHEAST AND EAST CENTRAL NEBRASKA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 815 PM UNTIL

300 AM CDT.



HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES WEST

NORTHWEST OF OMAHA NEBRASKA TO 20 MILES SOUTH SOUTHWEST OF KNOB

NOSTER MISSOURI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 421...WW 423...WW

424...WW 425...WW 426...



DISCUSSION...TWO QUASI-LINEAR CONVECTIVE SYSTEMS ARE BECOMING BETTER

ORGANIZED OVER CENTRAL AND NERN KS AS STORMS MOVE EWD AND NEWD 20-30

KT.  THE CONVECTIVE SYSTEMS ARE MOVING THROUGH A VERY UNSTABLE

ENVIRONMENT WITH MLCAPE OF 2500-3500 J/KG...COINCIDENT WITH STRONG

DEEP LAYER SHEAR OF 40-50 KT.  SEVERE STORM POTENTIAL IS EXPECTED TO

CONTINUE DOWNSTREAM TONIGHT IN ADVANCE OF A SHORT WAVE TROUGH MOVING

INTO THE CENTRAL PLAINS.  DAMAGING WIND GUSTS AND LARGE HAIL ARE

EXPECTED TO THE PRIMARY THREATS WITH THE ACTIVITY.  AN ISOLATED

TORNADO OR TWO IS ALSO POSSIBLE...ESPECIALLY WITH DISCRETE CELLS OR

BRIEF MESO-VORTICES EMBEDDED WITHIN THE QLCS/S.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 25030.





...WEISS

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