

017 

WWUS20 KWNS 182115

SEL8

SPC WW 182115

KSZ000-190300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 468

NWS STORM PREDICTION CENTER NORMAN OK

415 PM CDT THU JUN 18 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST AND CENTRAL KANSAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 415 PM UNTIL

1000 PM 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 50

STATUTE MILES EAST AND WEST OF A LINE FROM 5 MILES SOUTH

SOUTHWEST OF LIBERAL KANSAS TO 20 MILES NORTH NORTHWEST OF

RUSSELL KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 461...WW 463...WW

464...WW 465...WW 466...WW 467...



DISCUSSION...ISOLATED THUNDERSTORMS ARE DEVELOPING ALONG THE

INSTABILITY GRADIENT ACROSS SW KS WHERE SURFACE TEMPERATURES HAVE

WARMED INTO THE LOW-MID 90S AND BOUNDARY LAYER DEW POINTS IN THE

60S.  GIVEN RELATIVELY STEEP MID LEVEL LAPSE RATES AND SUBSTANTIAL

DEEP LAYER SHEAR BENEATH 50-70 KT SWLY FLOW ALOFT...A FEW ORGANIZED

MULTICELL CLUSTERS OR SUPERCELLS WILL BE CAPABLE OF PRODUCING LARGE

HAIL AND DAMAGING WINDS THROUGH LATE EVENING.  ADDITIONALLY...THERE

WILL BE SOME POTENTIAL FOR OTHER STORMS TO SPREAD INTO SW KS FROM

THE TX/OK PANHANDLE LATER THIS EVENING.



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 550. MEAN STORM

MOTION VECTOR 23025.





...THOMPSON

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