High Wind in Montana, January 18, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1055 PM MST TUE JAN 17 2012

UPDATED AVIATION

.UPDATE...
WEATHER DISTURBANCE ALOFT FROM SOUTHEAST B.C. INTO EASTERN
WASHINGTON WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA LATER
TONIGHT. BANDS OF SNOW AHEAD OF THIS FEATURE OVER THE NORTHWEST
ZONES WILL ALSO SPREAD SOUTHEAST. HAVE INCREASED POPS IN THE AREA
OF RADAR ECHOES FOR THE REST OF THIS EVENING AND OVER MOST OF THE
PLAINS AND ADJOINING MOUNTAINS AFTER MIDNIGHT. ALSO INCREASED POPS
IN THE MOUNTAINS OF SOUTHWEST MONTANA LATER TONIGHT. COLD FRONT
SOUTH OF A LINE FROM GREAT FALLS TO LEWISTOWN AT MID-EVENING WILL
SPREAD SOUTH REACHING TO NEAR A BOZEMAN TO WHITEHALL LINE BY EARLY
MORNING. HAVE ADJUSTED WIND FORECASTS TO REFLECT THIS AND ALSO
HAVE LOWERED LOWS FOR TONIGHT NORTH OF THE FRONT ESPECIALLY OVER
CENTRAL MONTANA AND THE NORTHERN PORTIONS OF SOUTHWEST MONTANA.
NORRIS HILL IS STAYING BELOW HIGH WIND CRITERIA AS OF MID-EVENING
BUT WITH UPPER FRONT EXPECTED TO MOVE THROUGH THE AREA LATER
TONIGHT THINK THERE IS AN OUTSIDE CHANCE OF REACHING HIGH WIND
CRITERIA SO HAVE DECIDED NOT TO CANCEL THE HIGH WIND WARNING. BLANK

&&

.AVIATION...
UPDATED 0600Z.
A QUASI-STATIONARY FRONT WILL REMAIN OVER CENTRAL MONTANA BUT SHOULD
STAY SOUTH OF KGTF THROUGH TONIGHT AND THURSDAY. THE FRONT IS SOUTH
OF A LINE FROM KGTF TO KLWT AS OF 06Z WEDNESDAY. MOIST FLOW ALOFT
WILL BRING SNOW TO THE AREA WITH WIDESPREAD MVFR/IFR CONDITIONS
AFTER 06Z WEDNESDAY. ALONG THE HI-LINE...LIGHT TO MODERATE SNOW IS
EXPECTED TONIGHT...HOWEVER THERE WILL BE A BREAK LATER WEDNESDAY
MORNING. GUSTY WINDS AT KBZN AND KHLN MAY CAUSE REDUCED VISIBILITIES
IN FALLING AND BLOWING SNOW WITH SOUTHWEST WINDS GUSTING TO 35KTS AT
TIMES. WIDESPREAD MOUNTAIN OBSCURATION WILL CONTINUE. MLV

&&

.PREV DISCUSSION...
/ISSUED 703 PM MST TUE JAN 17 2012/
FXUS65 KTFX 180203
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
703 PM MST TUE JAN 17 2012

UPDATE...
CUT BANK IS MEETING WIND CHILL WARNING CRITERIA SO WILL UPGRADE
THE ADVISORY TO A WARNING FOR GLACIER AND TOOLE COUNTIES FOR
TONIGHT. ALSO WILL CHANGE ELEVATIONS ABOVE 7000 FEET FOR GALLATIN
AND MADISON AND BEAVERHEAD COUNTIES FROM A WINTER WEATHER ADVISORY
TO A WINTER STORM WARNING BASED ON SNOWFALL TOTALS. FINALLY ON
THURSDAY AFTER HAVING LOOKED AT FORECAST SOUNDINGS WILL TONE DOWN
THE MENTION OF FREEZING RAIN OVER SOUTHWEST MONTANA. BLANK

&&

.PREV DISCUSSION...
/ISSUED 500 PM MST TUE JAN 17 2012/
TONIGHT THROUGH THURSDAY...NUMEROUS WINTER WEATHER HIGHLIGHTS HAVE
BEEN ISSUED TODAY. THE WINTER STORM WARNING OVER THE ROCKY
MOUNTAIN FRONT AND THE WIND CHILL ADVISORY OVER THE NORTHERN TIER
OF THE REGION WILL CONTINUE. A WINTER STORM WARNING HAS BEEN
ISSUED FOR CENTRAL MONTANA ABOVE 5000 FEET...WITH AN ADVISORY
BELOW 5000 FEET. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR
PORTIONS OF SOUTHWEST AND NORTH CENTRAL MONTANA...BASICALLY THE
REMAINING AREAS EXPECT HILL AND BLAINE COUNTIES. THE BULK OF THE
SNOW WILL BEGIN VERY LIGHTLY TONIGHT OVER NORTH CENTRAL
MONTANA...THEN SPREAD SLOWLY SOUTHWARD TOWARDS CENTRAL MONTANA BY
MORNING. LIGHT SNOW SNOW WILL BE POSSIBLE OVER MUCH OF THE REGION
ON WEDNESDAY...WITH A BIT HEAVIER SNOWFALL IN THE MOUNTAINS.
AGAIN...THIS WILL BE A PRO-LONGED SNOW EVENT...WITH GRADUAL
ACCUMULATIONS FOR MOST AREAS. THERE WILL BE SOME SHORT PERIODS OF
MODERATE/HEAVY SNOW...FOLLOWED BY PERIODS OF LIGHT SNOW OR
FLURRIES. TEMPERATURES WILL REMAIN COLD THROUGH THURSDAY
MORNING...THEN WARMER AIR WILL START TO PUSH NORTHWARD INTO
SOUTHWEST MONTANA. ENOUGH WARM AIR COULD PUSH IN ALOFT...THAT SOME
FREEZING RAIN WILL BE POSSIBLE IN THE VALLEYS OF SOUTHWEST MONTANA
ON THURSDAY. BRUSDA

THURSDAY NIGHT THROUGH TUESDAY NIGHT...MEDIUM RANGE MODELS CONTINUE
TO INDICATE THAT THE FLOW ALOFT WILL BECOME A MORE PROGRESSIVE
WESTERLY ONE DURING THIS PERIOD. HOWEVER...THERE ARE SIGNIFICANT
DIFFERENCES IN MOVING THE MODERATELY COOL AIRMASS AROUND NORTH
CENTRAL MONTANA. THEREFORE...RATHER THAN TRYING TO TIME THE
FLUCTUATIONS IN TEMPERATURES...HAVE DECIDED TO GO WITH A MORE
BROAD-BRUSHED OVERALL TREND FORECAST. MODELS SOMEWHAT AGREE IN
BRINGING THE WARMER (NEAR NORMAL) TEMPERATURES NORTHEAST INTO NORTH
CENTRAL MONTANA BY SATURDAY...AND TEMPERATURES GENERALLY REMAIN
CLOSE TO THESE LEVELS THROUGHOUT THE PERIOD. HOWEVER...THE AREA OF
THE CWA NEAR THE CANADIAN BORDER WILL REMAIN SLIGHTLY BELOW NORMAL.
THE GREATEST CHANCE FOR PRECIPITATION FOR THE ENTIRE AREA WILL BE
EARLY IN THE PERIOD (THROUGH SATURDAY)...AS MOISTURE OVERRUNS THE
LINGERING COOL AIRMASS. THE WESTERLY FLOW ALOFT WILL BE QUITE STRONG
DURING THIS TIME...WHICH MAY LEAD TO STRONG WINDS IN THE MOUNTAINS
(CAUSING AREAS OF BLOWING SNOW) AND IN THE SOUTHWEST MONTANA VALLEYS
(ON THE WARM SIDE OF THE SURFACE BOUNDARY). AS THE COOLER AIRMASS
EXITS NORTH CENTRAL MONTANA AND MORE WESTERLY DOWNSLOPE WINDS SPREAD
ACROSS THAT AREA...THE CHANCE FOR SHOWERS OVER THE PLAINS AND IN THE
VALLEYS WILL DECREASE THROUGH THE REMAINDER OF THE PERIOD.
HOWEVER...THE CONTINUED MOIST WESTERLY FLOW ALOFT WITH ASSOCIATED
WEAK DISTURBANCES WILL KEEP A GOOD CHANCE OF SNOW IN THE MOUNTAINS.
COULSTON

.PRELIMINARY POINT TEMPS/POPS...
GTF -12  -3  -7   9 /  60  90  90  90
CTB -26  -9 -12   1 / 100  90  90  90
HLN   7  15  11  28 /  60  90  90  90
BZN  15  21  21  32 /  20  90  90  90
WEY   6  19  17  29 /  40  90  90  90
DLN  15  23  23  36 /  50  80  80  80
HVR -17  -7 -13   1 /  60  70  80  80
LWT -10  -1  -4  11 /  60  80  90  80

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM WEDNESDAY TO 4 AM MST FRIDAY
FOR ELEVATIONS BELOW 5000 FEET FOR CASCADE...CENTRAL AND
SOUTHERN LEWIS AND CLARK...JUDITH BASIN...MEAGHER.

WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 4 AM MST FRIDAY FOR
ELEVATIONS ABOVE 5000 FEET FOR CASCADE...CENTRAL AND SOUTHERN
LEWIS AND CLARK...JUDITH BASIN...MEAGHER.

WINTER WEATHER ADVISORY FROM NOON WEDNESDAY TO 4 AM MST FRIDAY
CHOUTEAU...EASTERN GLACIER...EASTERN PONDERA...EASTERN TETON...
FERGUS...LIBERTY...TOOLE.

WIND CHILL ADVISORY UNTIL 8 AM MST WEDNESDAY BLAINE...CHOUTEAU...
EASTERN PONDERA...EASTERN TETON...HILL...LIBERTY.

WINTER WEATHER ADVISORY FROM 5 AM WEDNESDAY TO 4 AM MST FRIDAY
BEAVERHEAD...BROADWATER...GALLATIN...JEFFERSON...MADISON.

WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 4 AM MST FRIDAY FOR
ELEVATIONS ABOVE 7000 FEET FOR BEAVERHEAD...GALLATIN...MADISON.

WIND CHILL WARNING UNTIL 8 AM MST WEDNESDAY EASTERN GLACIER...
NORTHERN ROCKY MOUNTAIN FRONT...TOOLE.

HIGH WIND WARNING UNTIL 5 AM MST WEDNESDAY FOR A PORTION OF
MADISON COUNTY.

WINTER STORM WARNING UNTIL 4 AM MST FRIDAY NORTHERN ROCKY
MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT.

&&

SHORT TERM...BLANK
LONG TERM...MLS
AVIATION...MLS

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GREAT FALLS MT
1049 AM MST TUE JAN 17 2012

MTZ008>015-044>055-181200-
BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-
CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-
TOOLE-LIBERTY-EASTERN PONDERA-BLAINE-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS-
JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
1049 AM MST TUE JAN 17 2012

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

.DAY ONE...TODAY AND TONIGHT

NUMEROUS WINTER WEATHER HIGHLIGHTS ARE IN EFFECT ACROSS ALL OF
NORTH CENTRAL AND SOUTHWEST MONTANA.

A HIGH WIND WARNING IS IN EFFECT FOR PORTIONS OF MADISON COUNTY
THROUGH TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NUMEROUS WINTER WEATHER HIGHLIGHTS ARE IN EFFECT ACROSS ALL OF
NORTH CENTRAL AND SOUTHWEST MONTANA UNTIL AT LEAST FRIDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

ANY SPOTTER REPORTS OF SNOWFALL AMOUNTS...LOW VISIBILITIES OR ANY
OTHER SIGNIFICANT WEATHER IMPACTS...CAN BE REPORTED TO THE
NATIONAL WEATHER SERVICE FORECAST OFFICE IN GREAT FALLS.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
807 PM MST TUE JAN 17 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0806 PM     HEAVY SNOW       11 WSW BABB             48.80N 113.67W
01/17/2012  M10.0 INCH       GLACIER            MT   MESONET

            MANY GLACIER SNOTEL MEASURES 10.0 INCHES IN 24 HOURS.
            ELEVATION 4900 FEET.

&&

MLV