

053 

WWUS20 KWNS 170254

SEL9

SPC WW 170254

IAZ000-NEZ000-SDZ000-170900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 309

NWS STORM PREDICTION CENTER NORMAN OK

955 PM CDT MON JUN 16 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  CENTRAL AND WEST CENTRAL IOWA

  NORTHEAST NEBRASKA

  EXTREME SOUTHEAST SOUTH DAKOTA



* EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 955 PM

  UNTIL 400 AM CDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  ISOLATED VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES NORTHWEST

OF NORFOLK NEBRASKA TO 50 MILES NORTHEAST OF KNOXVILLE IOWA.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 303...TORNADO WATCH NUMBER 305. WATCH NUMBER

303 305 WILL NOT BE IN EFFECT AFTER 955 PM CDT. CONTINUE...WW

306...WW 307...WW 308...



DISCUSSION...CONVECTION IN NE NEB/NW IA WILL CONTINUE TO EXPAND AND

LIKELY MOVE ESEWD ALONG THE SLOW-MOVING OUTFLOW BOUNDARY INTO

CENTRAL IA...IN THE WAKE OF THE LEAD CONVECTIVE SYSTEM MOVING INTO

ERN IA.  A CONTINUED FEED OF UNSTABLE AIR FROM THE S/SW WILL

MAINTAIN STRONG UPDRAFTS AND THE RISK FOR LARGE HAIL...WHILE

DAMAGING GUSTS WILL ALSO BE POSSIBLE...ESPECIALLY IF STORMS CONGEAL

INTO ANOTHER BOWING SEGMENT FROM NE NEB INTO WRN IA.



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 550. MEAN STORM

MOTION VECTOR 29030.





...THOMPSON

