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WWUS20 KWNS 110027

SEL9

SPC WW 110027

COZ000-KSZ000-NEZ000-110800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 619

NWS STORM PREDICTION CENTER NORMAN OK

725 PM CDT SUN JUL 10 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST COLORADO

       FAR NORTHWEST KANSAS

       WESTERN AND CENTRAL NEBRASKA



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 725 PM UNTIL

300 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 60 MILES SOUTHWEST OF

MCCOOK NEBRASKA TO 40 MILES NORTH NORTHWEST OF ONEILL NEBRASKA.

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 617...WW 618...



DISCUSSION...TSTMS HAVE ORGANIZED ALONG A W-E ORIENTED GUST FRONT

SURGING NWD THROUGH NWRN KS AND NERN CO...AS WELL AS ALONG NE-SW

ORIENTED PRE-FRONTAL TROUGH EXTENDING FROM N-CNTRL TO SWRN NEB.  00Z

LBF SOUNDING SHOWS THE PRESENCE OF STEEP MIDLEVEL LAPSE RATES ATOP A

MOIST BOUNDARY LAYER WITH MLCAPE OF AROUND 3000 J/KG.  WHEN COUPLED

WITH A VERTICALLY VEERING WIND PROFILE AND 30-35 KT OF DEEP-LAYER

SHEAR...SETUP WILL SUPPORT ORGANIZED STORMS CAPABLE OF DAMAGING

WINDS AND LARGE HAIL.  THE NOCTURNAL STRENGTHENING OF THE LLJ BY

AROUND 03Z SHOULD SUPPORT UPSCALE GROWTH OF STORMS INTO AN MCS WITH

A CONTINUED THREAT FOR MAINLY DAMAGING WINDS.



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 27025.





...MEAD

