Blizzard and High Wind in Montana, November 19 to 20, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
525 AM MST MON NOV 19 2012

.DISCUSSION...

TODAY THROUGH WEDNESDAY...INCREASING SOUTHWEST FLOW ALOFT OVER THE
AREA TODAY AS THE PATTERN BECOMES ANALOGOUS TO THE NORTHERN
FIREHOSE. MOISTURE WILL IMPACT THE ROCKY MOUNTAIN FRONT AND
SIGNIFICANT ACCUMULATING SNOW WILL FALL AT THE HIGHER ELEVATIONS
FROM MIDDAY TODAY THROUGH TUESDAY. SNOW LEVELS WILL GENERALLY REMAIN
ABOVE 6000 FEET. A STRONG UPPER LEVEL JET WILL CONTINUE TO PUSH EAST
AND ACROSS THE COUNTY WARNING AREA TODAY. STRONG SURFACE WINDS ARE
EXPECTED ALONG THE ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS. GIVEN
THE STRONG WINDS...AND ACCUMULATING SNOW AT HIGHER ELEVATIONS...HAVE
ISSUED A BLIZZARD WARNING FOR ELEVATIONS ABOVE 6000 FEET FOR THE
ROCKY MOUNTAIN FRONT. STRONG WINDS AND FALLING SNOW SHOULD CONTINUE
INTO TUESDAY. STRONG WINDS WILL ALSO CONTINUE OVER THE PLAINS
ADJACENT TO THE ROCKY MOUNTAIN FRONT AND A HIGH WIND WARNING
CONTINUES FOR EASTERN GLACIER AND PONDERA COUNTIES AS WELL. A HIGH
WIND WATCH IS IN EFFECT TONIGHT FOR CASCADE AND JUDITH BASIN
COUNTIES AS THE CORE OF HIGHER WIND SPEEDS SHIFTS FURTHER SOUTH.
SHORTWAVE ENERGY MOVING ACROSS THE AREA WEDNESDAY WILL BRING
SCATTERED SHOWERS TO THE HIGH COUNTRY OF SOUTHWEST MONTANA AND
ISOLATED SHOWERS ELSEWHERE. TEMPERATURES WILL CONTINUE WELL ABOVE
SEASONAL AVERAGES THROUGH MIDWEEK. EMANUEL

WEDNESDAY NIGHT THROUGH MONDAY NIGHT...A SHORTWAVE TROUGH WILL MOVE
THROUGH THE TFX CWA WEDNESDAY AND DRAG A WEAK CANADIAN COLD FRONT
SOUTH ALONG THE HI-LINE. THIS WILL CONTINUE PRECIPITATION IN THE
MOUNTAINS WITH A CHANCE OF SHOWERS ALONG THE FRONTAL BOUNDARY.
HOWEVER...DOWNSLOPING WINDS ACROSS THE PLAINS OF CENTRAL MONTANA
(INCLUDING THE GREAT FALLS AND LEWISTOWN AREAS) WILL LESSEN THE
CHANCE FOR PRECIPITATION THERE. AN UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL THEN MOVE INTO THE AREA FOR THURSDAY THROUGH FRIDAY
NIGHT...FOR ONLY A CHANCE OF SHOWERS IN THE MOUNTAINS WITH
TEMPERATURES OF 5 TO 10 DEGREES ABOVE SEASONAL AVERAGES. THE
CONTINUING BREEZY WESTERLY DOWNSLOPING WINDS WILL GENERALLY KEEP THE
PLAINS DRY. MOISTURE AHEAD OF AN APPROACHING SHORTWAVE WILL BRING AN
INCREASING CHANCE OF PRECIPITATION TO THE AREA ON SATURDAY...AS
ANOTHER CANADIAN COLD FRONT BEGINS MOVING SOUTH INTO THE AREA TO
COOL TEMPERATURES OFF SLIGHTLY. HOWEVER...THIS SHORTWAVE WILL DEEPEN
AS IT MOVES INTO THE PACIFIC NORTHWEST AND NORTHERN ROCKIES FOR
SATURDAY NIGHT THROUGH SUNDAY NIGHT. FORECAST MODELS ARE IN BETTER
AGREEMENT TONIGHT WITH THE DETAILS OF THIS SYSTEM. CONFIDENCE IS
INCREASING THAT A STRONG SURGE OF COLD CANADIAN AIR WITH NORTHERLY
UPSLOPE WINDS WILL ACCOMPANY THIS MOIST SHORTWAVE...WHICH MAY BRING
A ROUND OF MEASURABLE SNOWFALL TO THE AREA. HAVE THEREFORE INCREASED
THE CHANCE OF SNOW ACROSS THE AREA AND LOWERED HIGHS MOSTLY INTO THE
30S FOR SUNDAY AND INTO THE 20S FOR MONDAY. WHAT IS STILL UNCERTAIN
IS JUST HOW MUCH PRECIPITATION WILL DEVELOP WITH THIS SYSTEM. THE
ECMWF INDICATES THAT SIGNIFICANT MOISTURE WILL DEVELOP...WHILE THE
GFS IS MUCH LESS MOIST. REGARDLESS...THIS WEEKEND SITUATION WILL
CONTINUE TO BE MONITORED FOR POSSIBLE WINTER WEATHER HIGHLIGHTS.
COULSTON

&&

.AVIATION...
UPDATED 1225Z.
VFR CONDITIONS ARE EXPECTED AT THE TFX TERMINAL LOCATIONS.
HOWEVER...SNOW OVER THE IDAHO PANHANDLE THIS MORNING WILL MOVE INTO
NORTHWEST/WESTERN MONTANA BY THIS AFTERNOON AND CONTINUE
OVERNIGHT...OBSCURING MOUNTAIN TOPS ALONG AND WEST OF THE
CONTINENTAL DIVIDE. OTHERWISE...SOUTHWESTERLY DOWNSLOPE WINDS WILL
INCREASE ACROSS THE AREA TODAY AND TONIGHT...GENERALLY KEEPING
PRECIPITATION AWAY FROM LOWER ELEVATIONS (INCLUDING THE TFX
TERMINALS) AND KEEPING CEILINGS MOSTLY ABOVE 15000 FEET MSL. WIND
GUSTS IN EXCESS OF 50 KTS WILL OCCUR OVER THE ROCKY MOUNTAIN FRONT
BY LATE MORNING. WINDS OF 15 TO 20 KTS WITH GUSTS OF UP TO 35 KT ARE
LIKELY OVER THE PLAINS BY THIS AFTERNOON...WITH SOME GUSTS
APPROACHING 45 KT OVER THE WESTERN PLAINS (INCLUDING KCTB AND KGTF).
LIGHTER BUT STILL GUSTY SOUTHERLY WINDS WILL LIKELY BLOW THROUGH THE
VALLEYS OF SOUTHWEST MONTANA (INCLUDING KHLN AND KBZN) THIS
AFTERNOON AND OVERNIGHT.  COULSTON

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  54  43  59  40 /  10  10  10  20
CTB  49  40  54  35 /  10  20  20  20
HLN  48  37  53  36 /  10  10  10  40
BZN  47  34  54  34 /  10  10  10  40
WEY  37  30  40  28 /  20  30  20  30
DLN  46  34  49  35 /  10  10  10  40
HVR  47  37  54  36 /   0  10  10  20
LWT  51  38  56  38 /   0   0   0  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM MST TUESDAY EASTERN GLACIER...
EASTERN PONDERA...NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY
MOUNTAIN FRONT.

BLIZZARD WARNING FROM 11 AM THIS MORNING TO 5 PM MST TUESDAY FOR
ELEVATIONS ABOVE 6000 FEET FOR NORTHERN ROCKY MOUNTAIN FRONT...
SOUTHERN ROCKY MOUNTAIN FRONT.

HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY AFTERNOON
CASCADE...JUDITH BASIN.

&&

SHORT TERM...EMANUEL
LONG TERM...COULSTON
AVIATION...COULSTON

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GREAT FALLS MT
550 AM MST MON NOV 19 2012

MTZ009-048-201245-
NORTHERN ROCKY MOUNTAIN FRONT-SOUTHERN ROCKY MOUNTAIN FRONT-
540 AM MST MON NOV 19 2012

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

.DAY ONE...TODAY AND TONIGHT

A BLIZZARD WARNING IS IN EFFECT FOR ELEVATIONS ABOVE 6000 FEET
BEGINNING AT 11 AM THIS MORNING.

A HIGH WIND WARNING IS IN EFFECT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A BLIZZARD WARNING FOR ELEVATIONS ABOVE 6000 FEET REMAINS IN
EFFECT UNTIL 5 PM MST TUESDAY.

THE HIGH WIND WARNING REMAINS IN EFFECT UNTIL 5 PM MST TUESDAY.

THERE IS THE POTENTIAL FOR WIDESPREAD PRECIPITATION AND COOLER
WEATHER NEXT WEEKEND.

.SPOTTER INFORMATION STATEMENT...

ANY SPOTTER REPORTS OF HIGH WINDS OR SNOWFALL WOULD BE GREATLY
APPRECIATED.

MTZ010-046-201245-
EASTERN GLACIER-EASTERN PONDERA-
540 AM MST MON NOV 19 2012

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

.DAY ONE...TODAY AND TONIGHT

A HIGH WIND WARNING IS IN EFFECT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE HIGH WIND WARNING REMAINS IN EFFECT UNTIL 5 PM MST TUESDAY.

THERE IS THE POTENTIAL FOR WIDESPREAD PRECIPITATION AND COOLER
WEATHER NEXT WEEKEND.

.SPOTTER INFORMATION STATEMENT...

ANY SPOTTER REPORTS OF HIGH WINDS WOULD BE GREATLY APPRECIATED.

MTZ012-050-201245-
CASCADE-JUDITH BASIN-
540 AM MST MON NOV 19 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MONTANA.

.DAY ONE...TODAY AND TONIGHT

A HIGH WIND WATCH IS IN EFFECT BEGINNING THIS EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE HIGH WIND WATCH REMAINS IN EFFECT THROUGH TUESDAY AFTERNOON.

THERE IS THE POTENTIAL FOR WIDESPREAD PRECIPITATION AND COOLER
WEATHER NEXT WEEKEND.

.SPOTTER INFORMATION STATEMENT...

ANY SPOTTER REPORTS OF HIGH WINDS WOULD BE GREATLY APPRECIATED.

MTZ008-011-013>015-044-045-047-049-051>055-201245-
BEAVERHEAD-HILL-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-
MADISON-TOOLE-LIBERTY-BLAINE-EASTERN TETON-FERGUS-JEFFERSON-
BROADWATER-MEAGHER-GALLATIN-
550 AM MST MON NOV 19 2012

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

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER THROUGH TONIGHT IS
LOW.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THERE IS THE POTENTIAL FOR WIDESPREAD PRECIPITATION AND COOLER
WEATHER NEXT WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.