High Wind in Montana, December 3, 2003

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
210 PM MST WED DEC 3 2003

.DISCUSSION...

TONIGHT...AN UPPER LEVEL SHORTWAVE TROUGH CONTINUES TO SWEEP ACROSS
THE STATE. SURFACE HIGH PRESSURE BUILDS OVER WESTERN AND CENTRAL
MONTANA...BEHIND THE CANADIAN COLD FRONT THAT CROSSED INTO NORTH
CENTRAL MONTANA DURING THE MID AFTERNOON. UPSLOPE FLOW WILL TRIGGER
SCATTERED SNOW SHOWERS OVER THE CENTRAL MONTANA MOUNTAINS...BUT
ONLY A SLIGHT CHANCE OF SNOW OVER THE PLAINS SINCE MOISTURE IS
RATHER LIMITED. MAIN BAND OF MOISTURE ASSOCIATED WITH UPPER LEVEL
TROUGH WILL BRING SCATTERED SNOW TO SOUTHWEST MONTANA. SNOW AMOUNTS
WILL BE GENERALLY LIGHT SO WILL NOT ISSUE ANY HIGHLIGHTS.
TEMPERATURES WILL DROP INTO THE TEENS ACROSS THE ENTIRE AREA.

THURSDAY THROUGH FRIDAY...HIGH PRESSURE SETTLES OVER CENTRAL MONTANA
ON THURSDAY AS AN UPPER LEVEL SHORTWAVE RIDGE BUILDS OVER THE
NORTHERN ROCKIES. WINDS WILL BE LIGHT AND TEMPERATURES CHILLY...BUT
THERE WILL BE LITTLE MOISTURE SO EXPECT ONLY A SLIGHT CHANCE OF
SNOW FLURRIES IN FAVORED UPSLOPE AREAS. THE RIDGE AND SURFACE HIGH
PRESSURE SYSTEM PROGRESS EAST ALLOWING A MOIST SOUTHWEST FLOW TO
DEVELOP BY FRIDAY MORNING. DOWNSLOPE WINDS AND OROGRAPHIC
PRECIPITATION WILL RETURN TO THE ROCKY MOUNTAIN FRONT. AFTER A VERY
COLD NIGHT...TEMPERATURES OVER THE PLAINS WILL WARM BACK INTO THE
40S FRIDAY AFTERNOON. MPJ

FRIDAY NIGHT THROUGH MONDAY...THE UPPER LEVEL RIDGE WILL BE OVER THE
MIDWEST WITH A TROF OVER THE EASTERN PACIFIC. THIS WILL CAUSE
MODERATE SW FLOW OVER THE CWA.  SEVERAL DISTURBANCES WILL MOVE THRU
THIS FLOW AND KEEP THE AIRMASS UNSETTLED BUT IN GENERAL THE CHANCE OF
PRECIP WILL BE LOW. A STRONGER SHORTWAVE MOVES ACROSS NORTHWEST
MONTANA ON SATURDAY. THIS HELPS DEVELOP A SURFACE LOW PRESSURE CENTER
OVER SOUTHERN ALBERTA AND SURFACE WINDS INCREASE. AN ASSOCIATED COLD
FRONT CROSSES THE NORTHERN ROCKIES OVERNIGHT AND TEMPS WILL DROP.
HIGH PRESSURE REBUILDS MONDAY BUT TEMP INCREASES WILL BE SLOW. ZELZER

TUESDAY AND WEDNESDAY...AT 00Z TUESDAY THE UPPER AIR RIDGE OVER THE
NORTHWEST IS PUSHING INTO WESTERN MONTANA AND BRINGING NORTHWEST
FLOW ALOFT TO THE STATE. THE SURFACE HIGH PRESSURE SYSTEM OVER
SOUTHERN IDAHO EXTENDS OVER THE WESTERN HALF OF MONTANA. THE SURFACE
HIGH RAPIDLY GIVES WAY TO A LOW PRESSURE TROUGH EXTENDING FROM
CANADA, AS THE UPPER AIR RIDGE MOVES ACROSS MONTANA. CLOUDY SKIES
AND NOT MUCH IN THE WAY OF WEATHER IS ASSOCIATED WITH THE TROUGH.
THE CANADIAN LOW WILL MOVE SOUTH THROUGH THE STATE BY WEDNESDAY
EVENING. THE UPPER AIR KEEPS THE FLOW EARLY WEDNESDAY FROM THE WEST
NORTHWEST AND DRYING AS THE UPPER AIR TROUGH BROADENS. THE FLOW IS
NORTHWEST BY WEDNESDAY NIGHT AND IS GENERALLY DRY. THE WEATHER AND
CLOUDS ASSOCIATED WITH THE SYSTEM ARE OVERDONE. THE DRY FLOW AND THE
RAPID MOVEMENT OF THE SYSTEM LOOKS TO KEEP THE PRECIPITATION AS
MOSTLY MOUNTAIN SHOWERS AND THE CLOUDS WILL BREAK UP RAPIDLY AS THE
SYSTEM PASSES THROUGH THE AREA.  PREWITT

.CCF NUMBERS
GTF BB 015/029 019/043 034 14200
    EBBBB 048/026 036/018 033/023 028/016 030 00000000000
CTB BB 016/026 015/040 031 14100
    EBBBB 046/024 033/014 032/019 027/012 029 00000000000
HLN BB 016/030 016/042 030 14100
    EEBBB 047/029 038/020 036/023 032/019 030 202222-0000
BZN BE 012/029 010/039 023 14400
    EEBBE 045/028 037/020 037/022 032/017 029 2-3222-0000
WEY BE 014/030 009/031 021 14500
    EEBBE 038/021 034/016 033/020 026/009 022 22433310001
DLN BE 015/032 019/041 031 1430-
    EEBBE 046/029 036/020 035/021 030/018 027 22333222202
HVR UB 017/032 010/041 027 14100
    BBBBB 045/026 037/017 030/016 027/012 034 00000000000
LWT BB 014/030 013/042 026 14300
    BBBBB 046/027 035/018 035/019 033/016 029 00000000000

.TFX...NONE.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
610 AM MST WED DEC 3 2003

MTZ008>015-044>055-041310-
BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-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-
610 AM MST WED DEC 3 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST MONTANA

.DAY ONE...TODAY

A HIGH WIND WARNING REMAINS IN EFFECT FOR THE NORTHERN ROCKY
MOUNTAIN FRONT UNTIL 3 PM TODAY. EXPECT WEST WINDS OF 25 TO 40
MPH...WITH GUSTS TO 65 MPH. SEE GTFNPWTFX FOR FURTHER DETAILS.

A PACIFIC COLD FRONT WILL MOVE EAST...ACROSS NORTH CENTRAL THIS
AFTERNOON AND SOUTHWEST MONTANA TONIGHT. EXPECT SCATTERED SHOWERS
OVER THE MOUNTAINS...AND ISOLATED SHOWERS OVER THE PLAINS.
TEMPERATURES WILL FALL QUICKLY IN THE LOWER 30S AND UPPER 20S BEHIND
THE FRONT. ANY RAIN ACTIVITY AHEAD OF THE FRONT WILL CHANGE TO SNOW
BEHIND IT. TRAVELERS ARE URGED TO DRIVE WITH CAUTION THIS
AFTERNOON AND EVENING AFTER FRONTAL PASSAGE...AS WET ROADWAYS MAY
FREEZE OVER.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

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.