

905 

WWUS20 KWNS 292033 CCA

SEL9

SPC WW 292033 CCA

IDZ000-MTZ000-ORZ000-300500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 429...CORRECTED

NWS STORM PREDICTION CENTER NORMAN OK

230 PM MDT TUE JUN 29 2010



CORRECTED FOR WATCH DISCUSSION



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL IDAHO

       WESTERN MONTANA

       NORTHEAST OREGON



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 230 PM UNTIL

1100 PM MDT.



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 110

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHEAST OF CUT BANK MONTANA TO 35 MILES SOUTH SOUTHWEST OF MC

CALL IDAHO.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 428...



DISCUSSION...WIDELY SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED

IN THE NEXT COUPLE OF HOURS FROM NE ORE ACROSS CENTRAL ID INTO WRN

MT.  THE CONVECTION WILL BE FOCUSED OVER THE HIGHER TERRAIN AND IN

THE VICINITY OF A BAROCLINIC ZONE ATTENDANT TO THE PAC NW MIDLEVEL

TROUGH.  SURFACE OBSERVATIONS REVEAL TEMPERATURES HAVE WARMED INTO

THE 80S ACROSS MUCH OF THIS AREA WITH DEWPOINTS HOLDING IN THE

50S...CONTRIBUTE TO MODERATE INSTABILITY /MLCAPE 1000-1500 J PER

KG/.  MEANWHILE...A BELT OF 50-70 KT SWLY MIDLEVEL FLOW IS RESULTING

IN EFFECTIVE BULK SHEAR IN EXCESS OF 50 KT AND RELATIVELY STRAIGHT

HODOGRAPHS...WHICH WILL FAVOR SPLITTING SUPERCELLS AND THE

POSSIBILITY OF SMALL BOWING SEGMENTS.  DAMAGING WINDS SHOULD BE THE

PRIMARY SEVERE THREAT...THOUGH THE STEEP LAPSE RATES/MODERATE

INSTABILITY WILL ALSO SUPPORT LARGE HAIL THROUGH EARLY TONIGHT.



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 24035.





...THOMPSON



639 

WWUS20 KWNS 292033

SEL9

SPC WW 292033

IDZ000-MTZ000-ORZ000-300500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 429

NWS STORM PREDICTION CENTER NORMAN OK

230 PM MDT TUE JUN 29 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL IDAHO

       WESTERN MONTANA

       NORTHEAST OREGON



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 230 PM UNTIL

1100 PM MDT.



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 110

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHEAST OF CUT BANK MONTANA TO 35 MILES SOUTH SOUTHWEST OF MC

CALL IDAHO.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 428...



DISCUSSION...WIDELY SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED

IN THE NEXT COUPLE OF HOURS FROM NE ORE ACROSS CENTRAL ID INTO WRN

MT.  THE CONVECTION WILL BE FOCUSED OVER THE HIGHER TERRAIN AND IN

THE VICINITY OF A BAROCLINIC ZONE ATTENDANT TO THE PAC NW MIDLEVEL

TROUGH.  SURFACE OBSERVATIONS REVEAL TEMPERATURES HAVE WARMED INTO

THE 80S ACROSS MUCH OF THIS AREA WITH DEWPOINTS HOLDING IN THE

50S...CONTRIBUTE TO MODERATE INSTABILITY /MLCAPE 1000-15000 J PER

KG/.  MEANWHILE...A BELT OF 50-70 KT SWLY MIDLEVEL FLOW IS RESULTING

IN EFFECTIVE BULK SHEAR IN EXCESS OF 50 KT AND RELATIVELY STRAIGHT

HODOGRAPHS...WHICH WILL FAVOR SPLITTING SUPERCELLS AND THE

POSSIBILITY OF SMALL BOWING SEGMENTS.  DAMAGING WINDS SHOULD BE THE

PRIMARY SEVERE THREAT...THOUGH THE STEEP LAPSE RATES/MODERATE

INSTABILITY WILL ALSO SUPPORT LARGE HAIL THROUGH EARLY TONIGHT.



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 24035.





...THOMPSON

