Special Weather Statement, NWS Missoula, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
221 PM MDT SAT AUG 6 2011

.DISCUSSION...UPPER LEVEL WEST FLOW WILL DOMINATE THE NORTHERN
ROCKIES THIS WEEKEND INTO EARLY NEXT WEEK. A THERMAL BOUNDARY WILL
REMAIN STRETCHED ACROSS SOUTHERN IDAHO COUNTY...THE CENTRAL
BITTERROOT/SAPPHIRE MOUNTAINS TO DRUMMOND AND WILL ACT AS A
FOCUSING MECHANISM FOR SCATTERED SHOWERS AND THUNDERSTORMS ALONG
AND SOUTH OF THIS LINE IN THE AFTERNOONS AND EVENINGS. TONIGHT AN
UPPER LEVEL WEATHER SYSTEM WILL MOVE THROUGH CANADA AND INCREASE
MOISTURE ACROSS NORTHWEST MONTANA. SUNDAY THE SURFACE HIGH
PRESSURE ON THE EAST SIDE OF THE DIVIDE WILL PROVIDE UPSLOPE FLOW
TO THE PARK THROUGH MONDAY. WITH THE INCREASED MOISTURE FROM THE
CANADIAN SYSTEM...THE TERRAIN AND FAVORABLE WINDS WILL ALLOW FOR
SHOWERS AND THUNDERSTORMS TO DEVELOP AND MAY LINGER THROUGH THE
OVERNIGHT HOURS. THE AIRMASS WILL CHANGE LITTLE OVER THE NEXT FEW
DAYS SO TEMPERATURES WILL REMAIN NEAR NORMAL.

LONG TERM...TUESDAY THROUGH FRIDAY...A WESTERLY FLOW WILL REMAIN
OVER THE REGION DURING THIS PERIOD. A WEAK DISTURBANCE MOVING WEST
TO EAST IN CANADA WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS...MAINLY
TO THE NORTH.

&&

.AVIATION...A STALLED THERMAL BOUNDARY AND LINGERING MOISTURE
ACROSS SOUTHERN IDAHO COUNTY THROUGH THE SOUTHERN BITTERROOTS AND
DRUMMOND TO LOCATIONS SOUTH IS SETTING OFF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS. THESE SHOWERS WILL IMPACT KSMN AND KBTM
THROUGH 03Z WITH THE MAIN IMPACTS BEING LOWERED CEILINGS AND
LOCALLY HEAVY RAIN. KMSO AND KGPI WILL SEE CUMULUS NEAR THE
AIRFIELDS BUT NO RAIN IS EXPECTED. SHOWERS AND CLOUDS WILL
DISSIPATE WITH LOSS OF HEATING THIS EVENING WITH SOME RIVER
VALLEYS SEEING PATCHY FOG DEVELOPMENT BY DAYBREAK.

&&

NOTE: FLOOD WATCHES...WARNINGS AND ADVISORIES WILL NOT BE LISTED BELOW.

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

SHORT TERM...MEAD
LONG TERM....KOLATA
AVIATION...MEAD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
231 PM MDT SAT AUG 6 2011

IDZ009-010-MTZ006-062115-
EASTERN LEMHI COUNTY-WESTERN LEMHI COUNTY-
BITTERROOT/SAPPHIRE MOUNTAINS-
231 PM MDT SAT AUG 6 2011

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN RAVALLI AND NORTHERN
LEMHI COUNTIES UNTIL 315 PM MDT...

AT 222 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 6 MILES WEST OF GIBBONSVILLE...OR 29 MILES NORTH
OF SALMON...MOVING EAST AT 25 MPH.

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

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...GIBBONSVILLE.

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 4548 11408 4566 11411 4567 11391 4563 11388
      4562 11382 4560 11379 4553 11382 4553 11377
      4552 11376 4548 11375
TIME...MOT...LOC 2031Z 265DEG 20KT 4558 11397

MEAD