High Wind in Montana, February 29, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
447 PM MST FRI FEB 29 2008

...UPDATE TO AVIATION...

.DISCUSSION...

TONIGHT THROUGH SUNDAY...A PROGRESSIVE WEATHER PATTERN WILL CONTINUE
THROUGH THE SHORT TERM. THE UPPER LEVEL RIDGE OVER THE REGION TODAY
WILL QUICKLY FLATTEN AND BE PUSHED OUT AS A TROUGH MOVES THROUGH THE
PACIFIC NORTHWEST AND APPROACHES THE AREA. THE GRADIENT WILL REMAIN
TIGHT THROUGH THE NIGHT FOR GUSTY WINDS...ESPECIALLY OVER THE ROCKY
MOUNTAIN FRONT. WILL ISSUE A SHORT HIGH WIND WARNING FOR THE ROCKY
MOUNTAIN FRONT...WINDS SHOULD DIE DOWN BY SATURDAY MORNING. THE
QUICK MOVING TROUGH WILL BRING A SHOT OF PRECIP TO THE CWA...MAINLY
IN THE SOUTHWEST AS THE DOWNSLOPE WINDS WILL KEEP THINGS DRIER OVER
THE PLAINS. SEVERAL INCHES OF SNOW ARE POSSIBLE AT HIGHER
ELEVATIONS. AT LOWER ELEVATIONS THE SNOW WILL MIX WITH RAIN...AND
THE WARM GROUND WILL KEEP MUCH SNOW FROM ACCUMULATING. TEMPERATURES
WILL COOL TO AROUND NORMAL WITH THE TROUGH. THOMSON

SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...MODELS IN GOOD AGREEMENT
AGAIN TONIGHT DURING THIS PERIOD. AN UPPER LEVEL RIDGE WILL MOVE
INTO WESTERN AND CENTRAL MONTANA SUNDAY NIGHT. WEAK ENERGY IN THE
RESULTING NORTHWEST FLOW ALOFT WILL BRING A CHANCE OF SNOW TO THE
MOUNTAINS OF WESTERN AND CENTRAL MONTANA. A STRONG SHORTWAVE TROUGH
WILL THEN MOVE INTO THE PACIFIC NORTHWEST ON MONDAY...INCREASING THE
WESTERLY FLOW ALOFT OVER THE AREA...AS WELL AS WESTERLY DOWNSLOPE
WINDS EAST OF THE ROCKIES. MOISTURE AHEAD OF THE SHORTWAVE WILL
BRING A GOOD CHANCE OF PRECIPITATION TO THE MOUNTAIN AREAS OF
WESTERN AND CENTRAL MONTANA ONCE AGAIN. THE CHANCE FOR PRECIPITATION
WILL INCREASE OVER THE ENTIRE AREA MONDAY NIGHT AS THE TROUGH MOVES
INTO MONTANA. THIS WILL CARRY OVER INTO TUESDAY AS AN ASSOCIATED
CANADIAN COLD FRONT MOVES THROUGH NORTH CENTRAL MONTANA AND SHIFTS
SURFACE WINDS MORE NORTHERLY AND UPSLOPING. TEMPERATURES WILL ALSO
COOL TO NEAR SEASONAL AVERAGES WITH THE PASSAGE OF THE COLD FRONT.
THE RESULTING COLD NORTHWEST FLOW ALOFT IN THE WAKE OF THE TROUGH
WILL KEEP AT LEAST A SLIGHT CHANCE OF SNOW OVER THE AREA TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT...AS TEMPERATURES COOL TO BELOW NORMAL
LEVELS DURING THIS TIME.  COULSTON

THURSDAY THROUGH FRIDAY...MODEL DIFFERENCES DETRACT FROM FORECAST
CONFIDENCE DURING THIS PERIOD. I WENT WITH A COMPROMISE SOLUTION OF
AN UPPER LEVEL RIDGE OF HIGH PRESSURE MOVING OVER THE PACIFIC
NORTHWEST BUILDING INTO WESTERN MONTANA. THIS RESULTS IN A
NORTHWESTERLY FLOW ALOFT OVER THE REGION. A FEW WEAK DISTURBANCES IN
THIS FAIRLY MOIST FLOW SHOULD PRODUCE PARTLY TO MOSTLY CLOUDY
SKIES WITH ISOLATED RAIN OR SNOW SHOWERS FOR MUCH OF THE FORECAST
AREA. THERE IS A BETTER CHANCE OF PRECIPITATION OVER MOST MOUNTAINS.
DOWNSLOPE WINDS WILL SPREAD EASTWARD RESULTING IN MODERATING
TEMPERATURES AND DRIER CONDITIONS ACROSS THE PLAINS AND LARGER
VALLEYS BY FRIDAY. EK

&&

.AVIATION...
UPDATED 2346Z. VFR CONDITIONS TO PREVAIL THROUGH TONIGHT BEFORE AN
UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVES QUICKLY ACROSS
THE REGION ON SATURDAY. COLD FRONT WILL REACH WESTERN MT BY
12Z...SPREADING RAIN AND MTN SNOW INTO THOSE AREAS LATE TONIGHT.
THE FRONT WILL MOVE EAST ACROSS CENTRAL AND SW MT SATURDAY MORNING
THROUGH EARLY AFTERNOON. TERMINALS FROM KHLN SOUTH WILL HAVE THE
GREATEST IMPACT FROM THE FRONT...WHERE A PERIOD OF RAIN...CHANGING
TO SNOW WILL BRING POSSIBLE IFR/LIFR CONDITIONS ALONG WITH
WIDESPREAD MTN OBSCURATIONS. FURTHER NORTH...ISOLATED SHOWERS ARE
EXPECTED WITH THE FRONTAL PASSAGE FROM KGTF TO KLWT WITH DRY
CONDITIONS TO THE NORTH. GUSTY WINDS WILL CONTINUE ON THE PLAINS
THROUGH THE NEXT 24 HRS WITH WINDS SHIFTING FROM SW TO W WITH THE
FRONTAL PASSAGE. VARIABLE WINDS IN THE SW MT VALLEYS WILL INCREASE
FROM THE SW AHEAD OF THE FRONT SATURDAY MORNING...THEN SHIFT TO
THE NW WITH THE FRONTAL PASSAGE...WITH A PERIOD OF GUSTY WINDS
POSSIBLE ALONG AND IMMEDIATELY FOLLOWING THE FRONT. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  35  47  27  40 /   0  30  10  10
CTB  30  44  26  36 /  10  10  10  10
HLN  29  44  24  43 /  10  60  20  20
BZN  30  45  20  40 /  10  70  20  20
WEY  24  40   3  32 /  20  80  60  30
DLN  30  37  18  38 /  10  60  20  20
HVR  30  49  21  39 /   0  10  10  20
LWT  31  46  24  35 /   0  40  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 8 PM THIS EVENING TO 8 AM MST SATURDAY
FOR MTZ009-048.

&&

SHORT TERM...THOMSON
LONG TERM...COULSTON/EK
AVIATION...HOENISCH

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GREAT FALLS MT
243 PM MST FRI FEB 29 2008

MTZ009-048-011300-
NORTHERN ROCKY MOUNTAIN FRONT-SOUTHERN ROCKY MOUNTAIN FRONT-
243 PM MST FRI FEB 29 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

A HIGH WIND WARNING IS IN EFFECT FROM 8 PM TONIGHT UNTIL 8 AM
SATURDAY MORNING. STRONG SOUTHWEST WINDS WILL DEVELOP THIS EVENING
AND CONTINUE THROUGH THE NIGHT. AREAS OF BLOWING SNOW ARE POSSIBLE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THE HIGH WIND WARNING REMAINS IN EFFECT UNTIL 8 AM SATURDAY
MORNING.

A PACIFIC STORM SYSTEM AND CANADIAN COLD FRONT WILL AFFECT THE
REGION MONDAY NIGHT AND TUESDAY. THIS SYSTEM HAS THE POTENTIAL TO
BRING STRONG WINDS AND SIGNIFICANT SNOWFALL TO THE AREA...BUT THE
TRACK AND TIMING OF THE SYSTEM ARE NOT YET CERTAIN. THIS STORM
SYSTEM WILL BE MONITORED CLOSELY FOR FUTURE WEATHER HIGHLIGHTS.

.SPOTTER INFORMATION STATEMENT...

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

MTZ010>013-044>047-049>051-011300-
EASTERN GLACIER-HILL-CASCADE-CHOUTEAU-TOOLE-LIBERTY-
EASTERN PONDERA-BLAINE-EASTERN TETON-JUDITH BASIN-FERGUS-
243 PM MST FRI FEB 29 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

THE POTENTIAL FOR HAZARDOUS WEATHER THIS AFTERNOON AND TONIGHT IS
LOW.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A PACIFIC STORM SYSTEM AND CANADIAN COLD FRONT WILL AFFECT THE
REGION MONDAY NIGHT AND TUESDAY. THIS SYSTEM HAS THE POTENTIAL TO
BRING STRONG WINDS AND SIGNIFICANT SNOWFALL TO THE AREA...BUT THE
TRACK AND TIMING OF THE SYSTEM ARE NOT YET CERTAIN. THIS STORM
SYSTEM WILL BE MONITORED CLOSELY FOR FUTURE WEATHER HIGHLIGHTS.

.SPOTTER INFORMATION STATEMENT...

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

MTZ008-014-015-052>055-011300-
BEAVERHEAD-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-JEFFERSON-
BROADWATER-MEAGHER-GALLATIN-
243 PM MST FRI FEB 29 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
MONTANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

AN UPPER LEVEL TROUGH MOVING THROUGH THE REGION WILL BRING SNOW TO
SOUTHWEST MONTANA TONIGHT...WITH SMALL ACCUMULATIONS POSSIBLE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SNOW WILL CONTINUE THROUGH THE DAY SATURDAY...WITH A FEW INCHES
ACCUMULATION POSSIBLE...MAINLY IN THE MOUNTAINS.

A PACIFIC STORM SYSTEM AND CANADIAN COLD FRONT WILL AFFECT THE
REGION MONDAY NIGHT AND TUESDAY. THIS SYSTEM HAS THE POTENTIAL TO
BRING STRONG WINDS AND SIGNIFICANT SNOWFALL TO THE AREA...BUT THE
TRACK AND TIMING OF THE SYSTEM ARE NOT YET CERTAIN. THIS STORM
SYSTEM WILL BE MONITORED CLOSELY FOR FUTURE WEATHER HIGHLIGHTS.

.SPOTTER INFORMATION STATEMENT...

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