

854 

WWUS20 KWNS 152014

SEL6

SPC WW 152014

NEZ000-SDZ000-WYZ000-160200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 706

NWS STORM PREDICTION CENTER NORMAN OK

210 PM MDT SAT AUG 15 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN NEBRASKA

       SOUTHWESTERN SOUTH DAKOTA

       EXTREME EASTERN WYOMING



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 210 PM UNTIL

800 PM MDT.



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 60 MILES NORTH

NORTHEAST OF CHADRON NEBRASKA TO 45 MILES SOUTH OF SCOTTSBLUFF

NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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.



DISCUSSION...STRONG FORCING ALOFT WILL AID IN THUNDERSTORMS

INTENSIFYING AND SPREADING EWD/NEWD FROM SERN WY INTO PORTIONS OF

SWRN SD AND WRN NEB INTO THE EVENING HOURS. DEEP LAYER SHEAR WILL

SUPPORT MID LEVEL ROTATION AND SEVERE HAIL. HOWEVER...STRONG LINEAR

FORCING SUGGESTS A LINE OF STORMS IS MORE LIKELY TO DEVELOP...WITH

ENVIRONMENTAL CONDITIONS SUPPORTIVE OF A STRONG CONSOLIDATED OUTFLOW

AND 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 27035.





...IMY

