

557 

WWUS20 KWNS 171646

SEL3

SPC WW 171646

KSZ000-NEZ000-172100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 593

NWS STORM PREDICTION CENTER NORMAN OK

1140 AM CDT FRI JUL 17 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWESTERN KANSAS

       SOUTHWESTERN NEBRASKA



EFFECTIVE THIS FRIDAY MORNING AND AFTERNOON FROM 1140 AM UNTIL

400 PM CDT.



HAIL TO 2.5 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES WEST

NORTHWEST OF MULLEN NEBRASKA TO 60 MILES SOUTHEAST OF GOODLAND

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 592...



DISCUSSION...ELEVATED STORMS DEVELOPED EARLIER THIS MORNING IN WRN

NEB WITHIN ZONE OF STRONG LOW LEVEL WARM ADVECTION. STRONGLY VEERING

WIND PROFILES...WITH MID LEVEL WINDS NEAR 50 KT...WERE RESULTING IN

50 TO 60 KT OF DEEP LAYER SHEAR. THIS AMOUNT OF SHEAR...ALONG WITH

STEEP LAPSE RATES AND MUCAPES AROUND 1000 J/KG...IS FAVORABLE FOR

SUPERCELLS WITH LARGE HAIL. AS TEMPERATURES WARM AND STORMS BECOME

SURFACE BASED THIS AFTERNOON...THE POTENTIAL FOR A SWD MOVING LINEAR

MCS AND WIND DAMAGE WILL INCREASE.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 34025.





...IMY

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