High Wind in Montana, August 26 to 27, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
226 PM MDT TUE AUG 26 2008

.DISCUSSION...

TONIGHT THROUGH THURSDAY...WEST TO NORTHWEST FLOW ALOFT CONTINUES TO
SET UP OVER MY FORECAST AREA AS THE UPPER TROUGH MOVES OFF TO THE
EAST. MAIN PROBLEM DURING THIS TIME FRAME WILL BE STRONG WINDS...
PARTICULARLY ALONG THE ROCKY MOUNTAIN FRONT. MODEL CROSS SECTIONS
THROUGH THE CONTINENTAL DIVIDE ARE SHOWING 60 KNOT WINDS NEAR OR
BELOW A STABLE LAYER TUESDAY MORNING THROUGH AFTERNOON. AT THE SAME
TIME...DOWNSLOPE PRESSURE GRADIENTS WILL INCREASE AND A SHORTWAVE
TROUGH WILL DIVE SOUTHEAST OUT OF BRITISH COLUMBIA. COMBINATION OF
FACTORS APPEARS TO FAVOR ISSUANCE OF A END HIGH WIND WARNING FOR
JUST OVER CRITERIA WINDS ALONG THE ROCKY MOUNTAIN FRONT. WILL
UPGRADE THE WATCH IN THIS AREA AND MOVE BEGINNING TIME UP A COUPLE
OF HOURS. OVER THE ADJACENT PLAINS...IT IS NOT CLEAR AT THIS TIME IF
CRITERIA WILL BE MET. WILL KEEP WATCH GOING IN THIS REGION BUT WILL
EXPAND THE AREA TO INCLUDE TOOLE COUNTY. AS THE PREVIOUSLY MENTIONED
TROUGH DIVES INTO THE AREA ABUNDANT MOISTURE WILL BE LIFTED OVER THE
CONTINENTAL DIVIDE FOR NUMEROUS SHOWERS OVER THE MOUNTAINS
WEDNESDAY. THE FEED OF MOISTURE WILL DIMINISH SOMEWHAT WEDNESDAY
NIGHT AND THURSDAY BUT ISOLATED TO SCATTERED SHOWERS WILL CONTINUE
IN THE GLACIER PARK REGION THROUGH THE PERIOD. WINDS WILL ALSO
REMAIN BREEZY ALTHOUGH SHOULD REMAIN BELOW HIGH WIND CRITERIA AFTER
WEDNESDAY EVENING. MPJ

THURSDAY NIGHT THROUGH SUNDAY NIGHT...HIGH PRESSURE WILL BE THE
DOMINANT WEATHER FEATURE PRESENT FROM THURSDAY NIGHT THRU EARLY
SATURDAY. ANTICIPATE MOSTLY CLEAR SKIES...DRY CONDITIONS...AND A
STEADY WARMING TREND THRU SATURDAY AFTERNOON. SOUTHWESTERLY FLOW
ALOFT WILL DEVELOP DURING SATURDAY AFTERNOON...AS A MOBILE PACIFIC
TROUGH OF LOW PRESSURE MOVES ACROSS THE NORTHERN ROCKIES. AS PER THE
LATEST GFS RUN...THE TROUGH AXIS IS EXPECTED TO CROSS THE FORECAST
AREA LATE SUNDAY...PRECEDED BY THE SURFACE COLD FRONT SUNDAY
AFTERNOON. SOME LOW AND MID LEVEL FORCING ARE EVIDENT IN THE MODELS
DURING THE SATURDAY THRU SUNDAY NIGHT PERIOD...ACCOMPANIED BY A
SLIGHT CHANCE OF PRECIPITATION...BECOMING CHANCE BY SUNDAY NIGHT
ACROSS MUCH OF THE HIGH TERRAIN WITHIN THE FORECAST AREA. THIS
TROUGH DOES NOT APPEAR TO HAVE A GREAT DEAL OF JET STREAM LEVEL
SUPPORT...THEREFORE THE PRECIPITATION FORECAST HAS BEEN KEPT
CONSERVATIVE DURING THIS TIME. AFTERNOON TEMPERATURES ARE EXPECTED
TO COOL SOME 10 DEGREES FROM SATURDAY TO SUNDAY ACROSS THE REGION.
ZUMPFE

MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DETRACT A LITTLE FROM
FORECAST CONFIDENCE DURING THIS PERIOD. I WENT WITH A COMPROMISE OF
AN UPPER LEVEL TROUGH MOVING EAST OF THE STATE MONDAY MORNING.
BEHIND THIS SYSTEM...A FEW DISTURBANCES IN A WEST TO NORTHWEST FLOW
ALOFT WILL RESULT IN PARTLY TO MOSTLY CLOUDY SKIES WITH ISOLATED
SHOWERS AND A FEW...MAINLY AFTERNOON AND EVENING THUNDERSTORMS. A
RIDGE OF HIGH PRESSURE BUILDS INTO WESTERN MONTANA TUESDAY AND WILL
BE RESPONSIBLE FOR DECREASING CLOUDS AND PRECIPITATION. TEMPERATURES
WILL BE COOL MONDAY BEFORE WARMING TO NEAR SEASONAL AVERAGES ON
TUESDAY.  EK

&&

.AVIATION...
UPDATED 1805Z.
VFR CONDITIONS ARE GENERALLY EXPECTED TO CONTINUE ACROSS NORTH
CENTRAL...CENTRAL...AND SOUTHWEST MONTANA THROUGH 18Z WEDNESDAY. AN
UPPER LEVEL TROUGH EXIT THE AREA THIS AFTERNOON...LEAVING A STRONG
NORTHWESTERLY FLOW ALOFT IN ITS WAKE. A FEW SHOWERS WILL LINGER
ALONG THE ROCKY MOUNTAIN FRONT AND ACROSS NORTH CENTRAL MONTANA
(INCLUDING KCTB AND KHVR TERMINALS) THROUGH THE AFTERNOON WITH
OCCASIONAL MVFR CONDITIONS AND SOME MOUNTAIN OBSCURATION. OVER
CENTRAL AND SOUTHWEST MONTANA...SKIES WILL BE PARTLY CLOUDY. ACROSS
THE ENTIRE AREA...WESTERLY SURFACE WINDS OF 15 TO 25 KT WILL
PREVAIL...WITH OCCASIONAL GUSTS TO 35 KT FROM THE KHLN TERMINAL
NORTH. CLOUDS AND WINDS WILL DECREASE THROUGH THE EVENING AND
OVERNIGHT. WINDS WILL INCREASE AGAIN DURING THE MORNING WITH
INCREASING HIGH CLOUDS.  COULSTON

&&

.FIRE WEATHER...
WINDY CONDITIONS WILL CONTINUE ACROSS THE DISTRICTS TONIGHT
THROUGH THURSDAY. HOWEVER...MINIMUM RELATIVE HUMIDITY VALUES ARE
EXPECTED TO REMAIN ABOVE 20 PERCENT. AS A RESULT...NO HIGHLIGHTS
ARE ANTICIPATED AT THIS TIME. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  45  72  46  78 /   0  10  10   0
CTB  43  65  42  70 /   0  10  10   0
HLN  47  74  50  79 /   0  20  10  10
BZN  40  79  42  82 /   0  10  10   0
WEY  36  69  36  72 /   0  10  10   0
DLN  38  73  40  75 /   0  10  10   0
HVR  40  72  41  78 /   0  10  10   0
LWT  40  69  43  75 /   0  10  10   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR MTZ010-044-046-049.

HIGH WIND WARNING FROM 10 AM TO 9 PM MDT WEDNESDAY FOR MTZ009-
048.

&&

SHORT TERM...MPJ
LONG TERM...ZUMPFE/EK
AVIATION...COULSTON

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GREAT FALLS MT
350 PM MDT TUE AUG 26 2008

MTZ009-048-271230-
NORTHERN ROCKY MOUNTAIN FRONT-SOUTHERN ROCKY MOUNTAIN FRONT-
350 PM MDT TUE AUG 26 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER THROUGH TONIGHT
IS LOW.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A HIGH WIND WARNING IS IN EFFECT FROM 10 AM TO 9 PM MDT WEDNESDAY
FOR THE ROCKY MOUNTAIN FRONT.

.SPOTTER INFORMATION STATEMENT...

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

MTZ010-044-046-049-271230-
EASTERN GLACIER-TOOLE-EASTERN PONDERA-EASTERN TETON-
350 PM MDT TUE AUG 26 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER THROUGH TONIGHT
IS LOW.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A HIGH WIND WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
WEDNESDAY EVENING FOR TOOLE...EASTERN GLACIER...EASTERN
PONDERA...AND EASTERN TETON COUNTIES.

.SPOTTER INFORMATION STATEMENT...

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

MTZ008-011>015-045-047-050>054-271230-
BEAVERHEAD-HILL-CASCADE-CHOUTEAU-
CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-LIBERTY-BLAINE-
JUDITH BASIN-FERGUS-JEFFERSON-BROADWATER-MEAGHER-
350 PM MDT TUE AUG 26 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

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

MTZ055-271230-
GALLATIN-
350 PM MDT TUE AUG 26 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 PM THIS EVENING FOR
THE EASTERN AND SOUTHERN PORTIONS OF GALLATIN COUNTY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER FOR WEDNESDAY
THROUGH MONDAY IS LOW.

.SPOTTER INFORMATION STATEMENT...

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

COHEN