Severe Thunderstorm Warning 6, NWS Missoula, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
246 PM MDT TUE JUN 29 2010

.DISCUSSION...CONVECTION STARTING TO FIRE ACROSS THE REGION THIS
AFTERNOON. SOME STRONG STORMS ANTICIPATED THROUGH THE EVENING
HOURS AS THERE IS QUITE A BIT OF INSTABILITY IN THE ATMOSPHERE.
STRONG GUSTY WINDS ARE THE MAIN POTENTIAL WITH STRONG STORMS. THE
AREAS MOST LIKELY FOR STRONGEST STORMS WILL BE IN WEST CENTRAL AND
SOUTHWEST MONTANA INTO SOUTHCENTRAL AND EAST CENTRAL IDAHO. THIS
INCLUDES MISSOULA, BUTTE, HAMILTON, SEELEY LAKE DOWN TO SALMON AND
DIXIE.

TONIGHT A SHORT WAVE OF ENERGY WILL MOVE NORTH AND WEST INTO THE
REGION AND BRING A CONTINUED THREAT OF CONVECTION THROUGH THE
OVERNIGHT AREAS. THE POTENTIAL EXISTS OVERNIGHT FOR STRONG STORMS
WITH THE TRIGGER BEING THE SHORT WAVE. MODEL SOUNDINGS INDICATE
POTENTIAL FOR SUFFICIENT DIRECTIONAL WIND SHEAR AT THE LOWER
LEVELS...CONDUCIVE TO TRIGGER STRONG STORMS. ANOTHER POTENTIAL
IMPACT MAY BE TRAINING OF STORMS IN CENTRAL IDAHO THROUGH WEST
CENTRAL MONTANA WHICH COULD PRODUCE LOCALIZED FLOODING CONCERNS.

ANOTHER ROUND OF POTENTIALLY STRONG TO SEVERE THUNDERSTORMS IS
POSSIBLE TOMORROW AFTERNOON...WITH THE MAIN THREAT AREA SHIFTING
TO THE SOUTH AND EAST...MAINLY IMPACTING SOUTHWEST MONTANA AND
LEMHI COUNTY IN IDAHO. SUFFICIENT WIND SHEAR...MOISTURE AND UPPER
LEVEL ENERGY WILL REMAIN IN PLACE TO CONTINUE THE POTENTIAL FOR
LARGE HAIL...STRONG WINDS AND HEAVY RAIN IN THE AFOREMENTIONED
AREAS. ELSEWHERE IN NORTHWEST MONTANA AND NORTHCENTRAL IDAHO A FEW
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE BUT ARE NOT
EXPECTED TO INTENSIFY. CHANCE OF PRECIPITATION AND THUNDERSTORMS
WILL DECREASE LATE WEDNESDAY NIGHT INTO THURSDAY.

ANOTHER LOBE OF ENERGY WILL ROTATE AROUND THE PACIFIC STORM SYSTEM
AND MOVE OVER THE NORTHERN ROCKIES THURSDAY NIGHT AND FRIDAY.
PRECIPITATION CHANCES WILL BE MAINLY FOCUSED ACROSS NORTHWEST
MONTANA AND CENTRAL IDAHO WITH ALL LOCATIONS SEEING THE COOLEST
TEMPERATURES OF THE FORECAST PERIOD. THE FLOW STAYS FAIRLY ACTIVE
OVER THE WEEKEND WITH THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS
FOR INDEPENDENCE DAY. THE TROUGH FINALLY MOVES EASTWARD ON MONDAY
WITH A RIDGE STARTING TO BUILD BACK INTO THE REGION MONDAY AND
TUESDAY.

&&

.AVIATION...WEATHER RELATED IMPACTS TO AVIATION WILL BE PRONOUNCED
BETWEEN 29/2000Z AND 30/0600Z FOR TERMINALS KGPI...KMSO...KSMN...AND KBTM.
SPECIFICALLY...THUNDERSTORM POTENTIAL IS HIGHEST DURING THIS TIME.
THERE IS A SLIGHT CHANCE THAT SOME OF THESE STORMS WILL PASS NEAR
AREA TERMINALS...PRODUCING LARGE HAIL AND STRONG OUTFLOW WINDS.
THUNDERSTORMS MAY OBSCURE TERRAIN FROM TIME TO TIME AS WELL.
THUNDERSTORM THREAT IS ANTICIPATED TO CONTINUE AFTER 30/0600Z...HOWEVER
THE LARGE HAIL AND DAMAGING WIND THREAT DIMINISHES THEREAFTER.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
ID...NONE.
&&

SHORT TERM...RPN
LONG TERM....PALLISTER
AVIATION...LOEFFELBEIN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MISSOULA MT
939 AM MDT TUE JUN 29 2010

IDZ005>008-MTZ002>006-043-291800-
NORTHERN CLEARWATER MOUNTAINS-SOUTHERN CLEARWATER MOUNTAINS-
OROFINO/GRANGEVILLE REGION-LOWER HELLS CANYON/SALMON RIVER REGION-
WEST GLACIER REGION-FLATHEAD/MISSION VALLEYS-
LOWER CLARK FORK REGION-MISSOULA/BITTERROOT VALLEYS-
BITTERROOT/SAPPHIRE MOUNTAINS-POTOMAC/SEELEY LAKE REGION-
939 AM MDT TUE JUN 29 2010 /839 AM PDT TUE JUN 29 2010/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
IDAHO...NORTHWEST MONTANA AND WEST CENTRAL MONTANA.

.DAY ONE...TODAY AND TONIGHT

STRONG SOUTHWESTERLY FLOW ALOFT AND A SURGE OF PACIFIC MOISTURE
WILL COMBINE WITH AN UNSTABLE ATMOSPHERE TO INCREASE THE THREAT OF
SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

IDZ009-010-MTZ007-291800-
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-BUTTE/BLACKFOOT REGION-
939 AM MDT TUE JUN 29 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
IDAHO AND WEST CENTRAL MONTANA.

.DAY ONE...TODAY AND TONIGHT

STRONG SOUTHWESTERLY FLOW ALOFT AND A SURGE OF PACIFIC MOISTURE
WILL COMBINE WITH AN UNSTABLE ATMOSPHERE TO INCREASE THE THREAT OF
SEVERE THUNDERSTORMS DURING THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ANOTHER ROUND OF POTENTIALLY SEVERE THUNDERSTORMS ARE POSSIBLE
ACROSS THE AREA WEDNESDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
226 PM MDT TUE JUN 29 2010

MTZ007-292115-
BUTTE/BLACKFOOT REGION-
226 PM MDT TUE JUN 29 2010

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL POWELL COUNTY UNTIL 315
PM MDT...

AT 219 PM MDT DOPPLER RADAR INDICATED A STRONG THUNDERSTROM...11
MILES NORTHEAST OF DRUMMOND...MOVING NORTHEAST AT 30 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM.

LOCATIONS NEAR THE PATH OF INCLUDE...HELMVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

&&

LAT...LON 4672 11299 4685 11326 4718 11288 4718 11286
      4717 11283 4713 11278 4684 11278
TIME...MOT...LOC 2025Z 221DEG 27KT 4685 11301