

048 

WWUS20 KWNS 170401

SEL9

SPC WW 170401

IAZ000-KSZ000-MOZ000-NEZ000-171000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 489

NWS STORM PREDICTION CENTER NORMAN OK

1105 PM CDT THU JUN 16 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF WESTERN IOWA

       PART OF NORTHEAST KANSAS

       PARTS OF NORTHWEST MISSOURI

       PARTS OF EASTERN NEBRASKA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1105 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF

NORFOLK NEBRASKA TO 25 MILES WEST SOUTHWEST OF KANSAS CITY

MISSOURI.  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 487...WW 488...



DISCUSSION...THUNDERSTORMS HAVE DEVELOPED RAPIDLY NERN KS/SERN NEB

IN RESPONSE TO WARM ADVECTION ON INCREASING LOW LEVEL JET COUPLED

WITH AVAILABLE INSTABILITY.  IN ADDITION THE SEVERE MCS OVER CENTRAL

NEB EXPECTED TO CONTINUE EWD INTO THE NRN PORTION OF THE WATCH AREA.

 PRIMARY THREAT WILL BE LARGE HAIL WITH NEW DEVELOPMENT AND DAMAGING

WINDS WITH STORMS MOVING IN FROM CENTRAL NEB.



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 24025.





...HALES

