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875 

WWUS20 KWNS 122354

SEL8

SPC WW 122354

NEZ000-130700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 158

NWS STORM PREDICTION CENTER NORMAN OK

655 PM CDT THU APR 12 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN AND CENTRAL NEBRASKA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 655 PM

UNTIL 200 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 WEST

NORTHWEST OF BURWELL NEBRASKA TO 35 MILES EAST SOUTHEAST OF

MCCOOK NEBRASKA.  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 157...



DISCUSSION...ELEVATED TSTMS ARE EXPECTED TO INCREASE IN COVERAGE

THIS EVENING TO THE N OF SURFACE WARM SECTOR WHERE DEEP-LAYER ASCENT

IS BEING ENHANCED BY SHORTWAVE TROUGH LIFTING NEWD THROUGH THE CNTRL

HIGH PLAINS.  THE COMBINATION OF STEEP MIDLEVEL LAPSE RATES...MUCAPE

OF 1000-1500 J/KG AND 35-40+ KT OF EFFECTIVE BULK SHEAR WILL BE

SUPPORTIVE OF SUPERCELLS CAPABLE OF MAINLY LARGE HAIL.



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 400. MEAN STORM

MOTION VECTOR 21020.





...MEAD

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