Wind Advisory 10, NWS Missoula, MT

000 
WWUS75 KMSO 181621
NPWMSO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
1021 AM MDT FRI APR 18 2008

...STRONG WINDS EXPECTED THIS AFTERNOON ACROSS LEMHI COUNTY...

.A VERY STRONG COLD FRONT IN ADVANCE OF THIS WEEKENDS ADVERTISED
COLD...WINTER-LIKE STORM...WILL PASS THROUGH LEMHI COUNTY. THE
STRONG PRESSURE GRADIENT ALONG THIS FRONTAL BOUNDARY WILL PRODUCE
SUSTAINED WINDS OF 25 TO 30 MPH WITH FREQUENT GUSTS OF 40 TO 50
MPH IN ADVANCE OF AND DIRECTLY BEHIND THE FRONT. WINDS WILL
DECREASE THIS EVENING AS THE FRONT EXITS THE AREA.

MTZ005>007-181730-
/O.CAN.KMSO.WI.Y.0010.080418T2100Z-080419T0300Z/
MISSOULA/BITTERROOT VALLEYS-BITTERROOT/SAPPHIRE MOUNTAINS-
BUTTE/BLACKFOOT REGION-
1021 AM MDT FRI APR 18 2008

...WIND ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS CANCELLED THE WIND
ADVISORY. 

AFTERNOON WIND GUSTS ARE EXPECTED TO REMAIN BELOW 40 MPH.

$$

IDZ009-010-190300-
/O.CON.KMSO.WI.Y.0010.080418T2100Z-080419T0300Z/
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-
1021 AM MDT FRI APR 18 2008

...WIND ADVISORY REMAINS IN EFFECT FROM 3 PM THIS AFTERNOON TO
9 PM MDT THIS EVENING...

A WIND ADVISORY REMAINS IN EFFECT FROM 3 PM THIS AFTERNOON TO
9 PM MDT THIS EVENING. 

SUSTAINED WINDS OF 25 TO 30 MPH WITH FREQUENT GUSTS OF 40 TO
50 MPH ARE EXPECT THIS AFTERNOON INTO EARLY THIS EVENING ACROSS
LEMHI COUNTY. TRAVELERS ALONG HIGHWAY 28 SOUTH OF TENDOY AND ALONG
US HIGHWAY 93 NEAR KRILEY CREEK WILL BE SUBJECT TO STRONG AND GUSTY
WINDS THIS AFTERNOON AND EVENING.

A WIND ADVISORY MEANS THAT STRONG WINDS ARE EXPECTED. DRIVING MAY
BE DIFFICULT...ESPECIALLY FOR HIGH PROFILE VEHICLES...SO USE
EXTRA CAUTION.

$$

000 
WWUS75 KMSO 190242
NPWMSO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
842 PM MDT FRI APR 18 2008


IDZ009-010-190345-
/O.EXP.KMSO.WI.Y.0010.000000T0000Z-080419T0300Z/
WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-
842 PM MDT FRI APR 18 2008

...WIND ADVISORY WILL EXPIRE AT 9 PM MDT THIS EVENING...

THE WIND ADVISORY WILL EXPIRE AT 9 PM MDT THIS EVENING. 

WINDS REMAIN BREEZY THIS EVENING BUT SUSTAINED WINDS AND GUSTS
HAVE DROPPED BELOW WIND ADVISORY LEVELS. THEREFORE THE WIND
ADVISORY FOR LEMHI COUNTY WILL BE ALLOWED TO EXPIRE.

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
929 PM MDT THU APR 17 2008

.UPDATE...ADJUSTMENTS MADE TO SKY COVER AND POPS FOR THIS EVENING.
ALSO TWEAKED MAXIMUM RH VALUES AS WELL.

&&

.DISCUSSION...MINOR ADJUSTMENTS MADE TO THE FORECAST TO DECREASE
SKY COVER IN EXTREME NORTHWEST MONTANA THIS EVENING DUE TO
STABILIZING CONDITIONS AND DECREASE IN CLOUD COVER. ALSO TOOK OUT ALL
ISOLATED PRECIPITATION WORDING FOR THIS EVENING TO THE NORTH AS
WELL. BIGGEST CHANGE WAS TO INCREASE THE MAXIMUM RH FORECAST TO
MORE PERSISTENT VALUES. ASIDE FROM THESE MINOR CHANGES...THE REST
OF THE FORECAST APPEARS TO BE ON TRACK AS A POTENT WEATHER SYSTEM
BEGINS TO AFFECT THE NORTHERN ROCKIES BY FRIDAY EVENING.

&&

.AVIATION...CLOUDS WILL BE ON THE INCREASE FRIDAY AS THE NEXT
WEATHER SYSTEM BEGINS TO AFFECT THE NORTHERN ROCKIES. A COLD FRONT
ASSOCIATED WITH THIS SYSTEM WILL CREATE STRONG AND GUSTY WINDS...MAINLY
IN THE AFTERNOON AS SURFACE PRESSURE GRADIENTS TIGHTEN. MOUNTAINS
AND PASSES WILL BE OBSCURED AT TIMES IN THE LATE AFTERNOON AND EVENING.

&&

.PREV DISCUSSION... /ISSUED 255 PM MDT THU APR 17 2008/

DISCUSSION...A WEAK RIDGE OF HIGH PRESSURE WILL CONTINUE TO PASS
THROUGH THE AREA TONIGHT. CLOUDS WILL PASS THROUGH THE RIDGE
THIS EVENING BEFORE SOME CLEARING OVERNIGHT. THIS RIDGE WILL BE
SHORT LIVED AS A STRONG LOW PRESSURE TROUGH ARRIVES TO THE WEST
COAST EARLY FRIDAY. THE ASSOCIATED COLD FRONT WILL BEGIN TO PASS
THROUGH THE NORTHERN IDAHO PANHANDLE AND EXTREME NORTHWEST MONTANA
LATE FRIDAY MORNING. AS THIS FRONT PASSES THROUGH THE FORECAST AREA
STRONG SOUTHWEST WINDS WILL OCCUR. THESE STRONG WINDS WILL
INCREASE TEMPERATURES IN SOUTHERN PORTIONS OF THE FORECAST AREA.

SATURDAY AND SUNDAY...A VIGOROUS COLD CLOSED UPPER LOW WILL ENTER
THE NORTHERN ROCKIES SATURDAY. CONFIDENCE IS HIGH WITH ALL MODELS
IN AGREEMENT AND CONSISTENT WITH THIS SOLUTION. ONLY MINOR
DISCREPANCIES WITH THE LOCATION OF A DEVELOPING 700 MB LOW AND
ASSOCIATED DEFORMATION ZONE. THE DEFORMATION ZONE OR BOUNDARY WILL
DETERMINE THE AREA OF MOST ENHANCED PRECIPITATION. THE GFS AND
ECMWF HAVE THE MAIN UPPER LOW A BIT FURTHER WEST WHICH WOULD FAVOR
THE FORMATION OF THIS MID LEVEL BOUNDARY IN CENTRAL IDAHO THROUGH
SOUTHWEST MONTANA. MOUNTAIN PASSES WILL BE MOST AFFECTED WITH THE
POTENTIAL OF SEVERAL INCHES OF SNOW IN SOME VALLEY LOCATIONS. THUS
WINTER STORM WATCHES FOR THESE AREAS HAVE BEEN POSTED. SUNDAY A
NORTHERLY FLOW WILL DEVELOP IN THE CAMAS PRAIRIE WHICH IS A
FAVORABLE PATTERN FOR ACCUMULATING SNOW IN GRANGEVILLE. THERE IS
SOME UNCERTAINTY WITH THIS SCENARIO AND MANY OTHER POSSIBLE
SOLUTIONS AS IT WILL DEPEND WHERE THIS MID LEVEL BOUNDARY SETS UP.

TEMPERATURES WILL FALL CONSIDERABLY THIS WEEKEND...SOME 15-25
DEGREES BELOW NORMAL FOR DAYTIME HIGHS. RECORD LOW MAXIMUM
TEMPERATURES WILL LIKELY BE BROKEN SUNDAY AND MONDAY IN SEVERAL
LOCATIONS. NIGHTTIME LOWS WILL FALL WELL BELOW FREEZING. INCREASED
LOW LEVEL MOISTURE AND CLOUDS OVER THE REGION WILL PREVENT
TEMPERATURES FROM FALLING MUCH BELOW 20...EXCEPT IN THE
BUTTE/PINTLAR REGION.

MONDAY THROUGH THURSDAY...THE CLOSED LOW WILL MOVE EAST BUT A
LONGWAVE TROF WILL LINGER ON THROUGH THE WEEK KEEPING TEMPERATURES
BELOW NORMAL WITH SNOW SHOWERS EACH DAY.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
     AFTERNOON FOR BITTERROOT/SAPPHIRE MOUNTAINS-BUTTE/BLACKFOOT
     REGION.

ID...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
     AFTERNOON FOR EASTERN LEMHI COUNTY-SOUTHERN CLEARWATER
     MOUNTAINS.

&&

SHORT TERM...DEROSA
PREVIOUS DISCUSSION....KITSMILLER/RPN
AVIATION...DEROSA

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MISSOULA MT
234 PM MDT THU APR 17 2008

IDZ005-007>009-MTZ001>005-043-181200-
NORTHERN CLEARWATER MOUNTAINS-OROFINO/GRANGEVILLE REGION-
LOWER HELLS CANYON/SALMON RIVER REGION-WESTERN LEMHI COUNTY-
KOOTENAI/CABINET REGION-WEST GLACIER REGION-
FLATHEAD/MISSION VALLEYS-LOWER CLARK FORK REGION-
MISSOULA/BITTERROOT VALLEYS-POTOMAC/SEELEY LAKE REGION-
234 PM MDT THU APR 17 2008 /134 PM PDT THU APR 17 2008/

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

AN UNSEASONABLY COLD UPPER LEVEL LOW PRESSURE SYSTEM DEVELOPING
IN THE GULF OF ALASKA WILL DIG OVER THE PACIFIC NORTHWEST LATE
FRIDAY INTO SATURDAY AND BECOME ENTRENCHED OVER THE NORTHERN
ROCKIES THIS WEEKEND INTO EARLY NEXT WEEK. THE COMBINATION OF
INCREASING MOISTURE AND A COLD CANADIAN AIRMASS WILL PROVIDE THE
INGREDIENTS FOR AREAS OF MODERATE TO HEAVY WET SNOW...DEVELOPING
SATURDAY AFTERNOON INTO SUNDAY ESPECIALLY OVER THE MOUNTAINS OF
WESTERN MONTANA AND PORTIONS OF NORTH CENTRAL IDAHO. TRAVEL MAY
BECOME DIFFICULT AND HAZARDOUS LATE SATURDAY...SUNDAY AND MONDAY...
ESPECIALLY OVER MOUNTAIN PASSES.

TEMPERATURES 10 TO 20 DEGREES BELOW NORMAL ARE LIKELY WITH SOME
LOCATIONS APPROACHING RECORD MINIMUM LEVELS EARLY NEXT WEEK AS
COLD CANADIAN AIR INFILTRATES THE REGION. TEMPERATURES WILL
STRUGGLE TO REACH 40 DEGREES IN MANY VALLEY LOCATIONS SUNDAY AND
MONDAY AFTERNOONS.

.SPOTTER INFORMATION STATEMENT...

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