watch

[Perry Lester]

THE NWS STORM PREDICTION CENTER HAS ISSUED A * SEVERE THUNDERSTORM WATCH FOR PORTIONS OF WESTERN IOWA NORTHEAST NEBRASKA SOUTHEAST SOUTH DAKOTA * EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 210 PM UNTIL 1000 PM CDT. * 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 60 STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH NORTHWEST OF YANKTON SOUTH DAKOTA TO 35 MILES EAST OF COLUMBUS NEBRASKA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5). 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.DISCUSSION...SEVERE STORMS --INCLUDING SUPERCELLS-- CONTINUE TO DEVELOP THIS AFTERNOON NEAR THE INTERSECTION OF THE SYNOPTIC FRONT AND AN OUTFLOW BOUNDARY OVER SERN SD INTO N-CNTRL AND NERN NEB. THIS ACTIVITY IS FORMING WITHIN A MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH RELATIVELY STRONG DEEP-LAYER SHEAR. THESE STORMS ARE EXPECTED TO SPREAD SEWD ACROSS THE WATCH AREA THIS AFTERNOON INTO EVENING WITH A RISK FOR LARGE HAIL AND DAMAGING WIND GUSTS. 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 32020. ...MEAD. IOWA COUNTIES INCLUDED ARE HARRISON MONONA PLYMOUTH WOODBURY . NEBRASKA COUNTIES INCLUDED ARE BURT CEDAR COLFAX CUMING DAKOTA DIXON DODGE KNOX MADISON PIERCE PLATTE STANTON THURSTON WASHINGTON WAYNE . SOUTH DAKOTA COUNTIES INCLUDED ARE BON HOMME CHARLES MIX CLAY DOUGLAS HUTCHINSON TURNER UNION YANKTON