

110 

WWUS20 KWNS 172105

SEL7

SPC WW 172105

NEZ000-SDZ000-WYZ000-180400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 167

NWS STORM PREDICTION CENTER NORMAN OK

305 PM MDT FRI MAY 17 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHWEST NEBRASKA INCLUDING THE NORTHERN PANHANDLE

  WESTERN SOUTH DAKOTA

  NORTHEAST WYOMING



* EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 305 PM UNTIL

  1000 PM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80

STATUTE MILES EAST AND WEST OF A LINE FROM 75 MILES SOUTHEAST OF

CHADRON NEBRASKA TO 75 MILES NORTH NORTHWEST OF RAPID CITY SOUTH

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 166...



DISCUSSION...SEVERAL CLUSTERS OF STORMS HAVE DEVELOPED OVER THE NEB

PANHANDLE AND NEAR THE BLACK HILLS OF SD...WITH VISIBLE IMAGERY

SHOWING THICKENING CU OVER PARTS OF NERN WY.  CONVECTION IS EXPECTED

TO INCREASE IN COVERAGE THROUGH THE EVENING WITHIN AN ENVIRONMENT

CHARACTERIZED BY MODERATE INSTABILITY /MLCAPE OF 1000-2000 J PER KG/

AND DEEP LAYER SHEAR OF 40-45 KT.  THIS WILL FAVOR POSSIBLE

SUPERCELLS INITIALLY...ALTHOUGH ACTIVITY MAY GROW UPSCALE THIS

EVENING IN RESPONSE TO AN INCREASING LOW LEVEL JET OVER THE PLAINS.

LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREATS.



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 24030.





...WEISS

