Severe Thunderstorm Warning 17, NWS Missoula, MT

000 
WWUS55 KMSO 170343
SVSMSO

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
943 PM MDT SAT JUN 16 2007

MTC023-093-170353-
/O.CAN.KMSO.SV.W.0017.000000T0000Z-070617T0400Z/
SILVER BOW MT-DEER LODGE MT-
943 PM MDT SAT JUN 16 2007

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DEER LODGE AND
NORTHERN SILVER BOW COUNTIES IS CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS SINCE MOVED EAST OF THE 
DIVIDE. THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN 
CANCELLED. 


LAT...LON 4611 11293 4624 11269 4626 11265 4626 11256
      4618 11259 4617 11252 4609 11251 4598 11276
      4598 11281

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
831 PM MDT SAT JUN 16 2007

.UPDATE...MAIN UPDATE THIS EVENING WILL BE TO REMOVE STRONG
THUNDERSTORM POSSIBILITY. HEATING OF THE DAY IS DECREASING AND
SEVERE THUNDERTORM THREAT. SCATTERED SHOWERS AND THUNDERSTORMS
WILL CONTINUE THIS EVENING IN SOUTHWEST MONTANA INTO SOUTHCENTRAL
IDAHO. THIS ACTIVITY WILL PERSIST OVERNIGHT WITH SOME DECREASE IN
AREAL COVEREAGE. UPPER LOW IN NORTHEAST WASHINGTON IS PRODUCING
SCATTERED SHOWERS AND THUNDERSTORMS. THIS LOW CONTINUES ON TRACK
TO MOVE OVER NORTHWEST MONTANA OVERNIGHT PRODUCING SCATTERED
SHOWERS AND THUNDERSTORMS.

&&

AVIATION...SCATTERED SHOWERS AND THUNDERSTORMS THROUGHOUT WESTERN
MONTANA AND NORTH-CENTRAL IDAHO WILL IMPACT TERMINAL AND ROUTE
FORECASTS THIS EVENING. MOUNTAINS WILL BECOME OBSCURED IN CLOUDS
AND SHOWERS/THUNDERSTORMS WITH LOCAL VISIBILITIES REDUCED IN
PRECIPITATION. CONDITIONS ARE EXPECTED TO IMPROVE AFTER DARK
ACROSS WEST-CENTRAL MONTANA AND NORTH-CENTRAL IDAHO. PLEASE SEE
APPROPRIATE TAFS AND TWEBS. PLEASE SEE APPROPRIATE TAFS AND TWEBS.

&&

.PREV DISCUSSION... /ISSUED 226 PM MDT SAT JUN 16 2007/

DISCUSSION...A DEEP LOW PRESSURE SYSTEM WAS MOVING INTO
WASHINGTON THIS AFTERNOON. THE AIR MASS AHEAD OF THIS SYSTEM WILL
BECOME QUITE UNSTABLE. IN ADDITION...CONSIDERABLE DYNAMICAL LIFT
WILL BE PROVIDED BY LOW-LEVEL (850-700MB) MASS CONVERGENCE AS WELL
AS A STRONG JET MAXIMA (AT 300MB) NOSING INTO THE AREA. VERTICAL
WIND SHEAR (MOSTLY SPEED SHEAR) WILL FAVOR ORGANIZED CONVECTION
THROUGH THE EVENING HOURS. THE GREATEST SEVERE THREAT APPEARS TO
EXIST ACROSS WEST-CENTRAL MONTANA. ALTHOUGH SOME THUNDERSTORM
ACTIVITY WILL LAST WELL INTO THE NIGHT...STRONGER CONVECTION WILL
ONLY LAST THROUGH THE EVENING.

SUNDAY...AS THE LOW SYSTEM TRACKS DIRECTLY OVER WESTERN MONTANA
EARLY SUNDAY...MOISTURE WILL CIRCULATE NORTH AROUND THE LOW AND
DROP INTO NORTHWEST MONTANA MAINTAINING CLOUDS AND HIGHER POPS
THERE. ACROSS WEST-CENTRAL MONTANA AND LEMHI COUNTY...A STRONG
WEST SURFACE PRESSURE GRADIENT DEVELOPS AS A COLDER AIR MASS
SETTLES INTO THE WESTERN MONTANA AND NORTHERN IDAHO. STRONG
NORTHWESTERLY WINDS ALOFT WILL HELP SUPPORT GUSTY WINDS DURING THE
DAY. IT SHOULD BE A COOL DAY WITH TEMPERATURES RUNNING A GOOD 10
TO 18 DEGREES BELOW NORMAL.

SUNDAY NIGHT...THE UPPER FLOW PATTERN BECOMES MORE ZONAL
(WESTERLY) WITH THE JET STREAM LIFTING NORTHWARD. THE POTENTIAL
FOR PRECIPITATION WILL GRADUALLY DECREASE AND BECOME FOCUSED
MAINLY OVER THE NORTHERN MOUNTAINS.

MONDAY THROUGH FRIDAY...UPPER LEVEL LOW WILL GRADUALLY EXIT THE
REGION TO THE EAST...TAPERING OFF SHOWER ACTIVITY INTO MONDAY
NIGHT. BEHIND THIS SYSTEM...LONG RANGE MODELS CONTINUE TO
INDICATE A RATHER STRONG RIDGE OF HIGH PRESSURE SETTING UP OVER
THE NORTHERN ROCKIES TUESDAY. AS THIS FEATURE ESTABLISHES
ITSELF...TEMPERATURES WILL WARM THROUGH THE WEEK TO ABOVE
SEASONABLE NORMALS. RIDGE AXIS BEGINS TO MOVE TO THE EAST BY
THURSDAY AFTERNOON HOWEVER...PLACING THE REGION IN SOUTHWESTERLY
FLOW WITH THE POSSIBILITY OF AFTERNOON SHOWERS AND THUNDERSTORMS
ONCE AGAIN.

&&

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

SHORT TERM...RPN
LONG TERM....VIA
AVIATION...RPN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MISSOULA MT
213 PM MDT SAT JUN 16 2007

MTZ001>007-043-170600-
KOOTENAI/CABINET REGION-WEST GLACIER REGION-
FLATHEAD/MISSION VALLEYS-LOWER CLARK FORK REGION-
MISSOULA/BITTERROOT VALLEYS-BITTERROOT/SAPPHIRE MOUNTAINS-
BUTTE/BLACKFOOT REGION-POTOMAC/SEELEY LAKE REGION-
213 PM MDT SAT JUN 16 2007

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

A FRONTAL BOUNDARY WILL CONTINUE TO PASS THROUGH THE AREA THIS
AFTERNOON AND EVENING. STRONG THUNDERSTORMS WILL FORM ALONG AND
AHEAD OF THIS BOUNDARY WITH THE POTENTIAL FOR SOME TO BECOME
SEVERE. THE MAIN THREATS ASSOCIATED WITH THESE STORMS WILL BE
GUSTY WINDS AND LARGE HAIL. BEHIND THE FRONT GUSTY WESTERLY WINDS
WILL DEVELOP.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

GUSTY WESTERLY WINDS WILL PERSIST THROUGH SUNDAY EVENING AS THE
PRESSURE GRADIENT REMAINS TIGHT.

.SPOTTER INFORMATION STATEMENT...

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