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349 

WWUS20 KWNS 190228

SEL9

SPC WW 190228

KSZ000-NEZ000-190900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 509

NWS STORM PREDICTION CENTER NORMAN OK

925 PM CDT SAT JUN 18 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL KANSAS

       SOUTH CENTRAL NEBRASKA



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 925 PM

UNTIL 400 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 70

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES EAST

NORTHEAST OF HASTINGS NEBRASKA TO 20 MILES SOUTH SOUTHWEST OF

MEDICINE LODGE KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 503...WW 504...WW

505...WW 506...WW 507...WW 508...



DISCUSSION...TWO SMALL CONVECTIVE SYSTEMS...ONE IN S CNTRL NEB AND

THE OTHER IN W CNTRL KS...EXPECTED TO CONTINUE EWD WITH GENERAL WSW

FLOW ALOFT.  ELY COMPONENT TO LOW LVL FLOW...AND POOL OF STRONG

SFC-BASED INSTABILITY ALONG AND N OF STALLED SHALLOW BOUNDARY IN SRN

KS SHOULD SUPPORT A CONTINUED RISK FOR SVR WIND/HAIL WITH SRN

CLUSTER.  STORMS ALSO MAY PROPAGATE W AND N INTO SRN PART OF WW FROM

CLUSTER NOW FORMING NEAR ICT.  EVOLUTION OF NRN CLUSTER IS SOMEWHAT

MORE UNCERTAIN GIVEN WEAKER SFC-BASED INSTABLITY AND SOMEWHAT WEAKER

LOW LVL FORXCING FOR ASCENT.  BUT GIVEN STRENGTH OF EXISTING STORMS

AND SOME ASCENT PROVIDED BY IMPULSES ALOFT...SETUP MAY SUPPORT

CONTINUED SVR THREAT WITH THIS ACTIVITY AT LEAST THROUGH LATE

TONIGHT.



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 500. MEAN STORM

MOTION VECTOR 28030.





...CORFIDI

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