URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 485 NWS STORM PREDICTION CENTER NORMAN OK 125 PM PDT SAT JUL 14 2012 THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF IDAHO EASTERN OREGON SOUTHEAST WASHINGTON EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 125 PM UNTIL 1000 PM PDT. 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 125 STATUTE MILES EITHER SIDE OF A LINE FROM 40 MILES SOUTH SOUTHWEST OF BAKER OREGON TO 70 MILES EAST SOUTHEAST OF LOWELL IDAHO. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5). 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 AND SEVERE TSTMS SHOULD INCREASE IN COVERAGE AND DEVELOP EAST ACROSS PARTS OF ERN ORE/SERN WA AND ADJACENT AREAS OF CNTRL ID THROUGH LATE THIS AFTERNOON AND INTO THE EVENING. THIS DEVELOPMENT IS EXPECTED TO OCCUR AS AN UPPER LOW/VORTICITY CENTER BEGINS TO EJECT ENEWD ACROSS THE REGION. LIFT WITH THIS DISTURBANCE WILL ACT ON A MODERATELY UNSTABLE AIRMASS WHILE A BAND OF 30-40KT MID LEVEL FLOW PIVOTS AROUND THE EJECTING IMPULSE TO PROVIDE SUFFICIENT EFFECTIVE SHEAR FOR STORM ORGANIZATION AND PERSISTENCE. FARTHER EAST...ANOTHER IMPULSE MIGRATING NORTH WITHIN MONSOONAL MOISTURE PLUME SHOULD AID STORM DEVELOPMENT AND SEVERE WIND/HAIL POTENTIAL ACROSS SERN ID THROUGH LATE AFTERNOON. 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 450. MEAN STORM MOTION VECTOR 25025.
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