Winter Storm in Montana, March 5 to 6, 2004

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MONTANA
230 PM MST FRI MAR 5 2004

.DISCUSSION...

TONIGHT AND SATURDAY...STRONG SHORTWAVE TROUGH AND AN ASSOCIATED
SURFACE COLD FRONT MOVES ACROSS THE NORTHERN ROCKIES OVERNIGHT.
ABUNDANT PACIFIC MOISTURE WILL SPREAD SNOW ACROSS THE ROCKIES AND THE
SOUTHWEST MOUNTAINS. IN ADDITION...A STRONG DOWNSLOPE PRESSURE
GRADIENT AND MID LEVEL WINDS WILL CAUSE WIDESPREAD BLOWING SNOW IN
THE MOUNTAINS AND HIGH WINDS ACROSS THE PLAINS. THE WINTER STORM
WARNING AND HIGH WIND WARNING FOR THE ROCKY MOUNTAIN FRONT LOOK GOOD
AND WILL BE CONTINUED. THE WINTER WEATHER ADVISORY IN SOUTHWEST
MONTANA LOOKS MORE PROBLEMATICAL...AM NOT CONVINCED THAT 2 TO 4
INCHES OF SNOW WILL MATERIALIZE IN THE VALLEYS. HOWEVER...BLOWING
SNOW POTENTIAL LOOKS GOOD. IN ADDITION...MODELS SHOW THE BEST QPF
BEFORE MIDNIGHT. WILL CONTINUE THE ADVISORY AND WILL EMPHASIZE
BLOWING SNOW...BUT WILL MOVE THE BEGINNING TIME UP TO EARLY THIS
EVENING. PRECIPITATION DECREASES AS THE DISTURBANCE MOVES EAST
TOMORROW. FORECAST WILL EMPHASIZE COOLER TEMPERATURES AND CONTINUED
STRONG WINDS. MPJ

SATURDAY NIGHT THROUGH TUESDAY NIGHT...MODELS ARE IN DECENT
AGREEMENT THROUGH THE PERIOD. 12Z GFS/UKMET/CANADIAN APPEAR TO BE
TOO WEAK WITH THE SHORTWAVE ENERGY OVER THE NORTHERN PACIFIC...WHILE
THE ETA IS A BIT DEEPER. A LOOK AT WATER VAPOR IMAGERY INDICATES THE
DEEPER ETA APPEARS TO BE CORRECT HERE...SO WILL FOLLOW IT THROUGH
THE MIDDLE OF THE PERIOD. LATER IN THE PERIOD...THINK THE CANADIAN
IS A BIT TOO AMPLIFIED WITH ENERGY AROUND 140 WEST. WILL USE THE
LESS AMPLIFIED AND FURTHER NORTH GFS...WHICH IS FAIRLY SIMILAR TO
YESTERDAYS ECMWF.

SPECIFICALLY...A BRISK NORTHWESTERLY FLOW WILL CONTINUE FOR MUCH OF
THE PERIOD. SHORTWAVE ENERGY WILL DIVE SOUTHWEST IN THE FLOW ON
SATURDAY NIGHT. WILL KEEP THE LOWER POPS GOING OVER THE WESTERN AND
SOUTHWESTERN MOUNTAINS DUE TO DYNAMICS IN THE AREA. WILL ALSO KEEP
LOW POPS IN OVER THESE AREAS ON SUNDAY AND SUNDAY NIGHT AS MOISTURE
OVERRIDES A BUILDING RIDGE. THE RIDGE WILL THEN PROPAGATE EAST INTO
THE ROCKIES...WITH THE AXIS BUILDING INTO WESTERN AND CENTRAL
MONTANA ON TUESDAY. SHORTWAVE ENERGY STREAMING ACROSS SOUTHERN
CANADA WILL PREVENT THE RIDGE FROM BECOMING TOO AMPLIFIED. WILL GO
WITH ZERO POPS OVER ALL AREAS STARTING ON MONDAY WITH RIDGE AXIS
APPROACHING AND DYNAMICS STAYING NORTH. WINDS WILL STAY UP THROUGH
MOST OF THE PERIOD WITH 700 MB GRADIENTS REMAINING HIGH. WINDIEST
DAY WILL BE SUNDAY...WITH THE ETA PROGS INDICATING WINDS OF OVER 65
KNOTS. WILL GENERALLY WARM TEMPERATURES THROUGH THE PERIOD. WILL GO
WARMEST ON MONDAY AND TUESDAY WITH DOWNSLOPING AND SUBSIDENCE
BENEATH THE RIDGE COINCIDING. SCHAUMANN

TUESDAY NIGHT THROUGH FRIDAY...MODELS KEEP LONG WAVE RIDGE OVER
MONTANA AND THE INTER-MOUNTAIN WEST INTO THURSDAY...THEN RIDGE
FLATTENS AND FLOW BECOME MORE ZONAL. HOWEVER...SEVERAL SHORT WAVE
TROUGHS WILL MOVE THROUGH THE RIDGE DURING THIS PERIOD. THUS
TEMPERATURES WILL NOT BE AS MILD AS MODELS INDICATE. THOUGH IT WILL
BE MOSTLY DRY...WITH ONLY A SLIGHT CHANCE OF SHOWERS OVER THE ROCKY
MOUNTAINS AND THE SOUTHWEST MOUNTAINS. TEMPERATURES WILL REMAIN ABOVE
SEASONAL AVERAGE. WILLIAMSON DC

&&

.CCF NUMBERS
GTF NN 028/041 026/050 037 14200
    BBBBE 056/036 058/033 051/029 051/028 049 00000000000
CTB NN 025/039 026/048 037 14200
    BBBBN 055/035 053/031 051/026 045/024 046 00000000000
HLN EN 029/039 025/048 029 14530
    BBEBE 053/027 054/029 049/028 050/026 048 00000000000
BZN EE 024/036 021/047 025 14630
    BBBBE 049/020 047/023 045/022 046/020 046 00000000000
WEY SE 014/029 008/035 012 14863
    BBEEE 039/012 036/014 035/007 035/009 036 320001210-0
DLN EE 023/037 023/049 028 1452-
    BBEEE 049/028 050/028 047/026 047/025 046 --00000-000
HVR NN 026/037 017/047 031 14200
    BBBBB 055/030 054/028 046/024 047/024 046 00000000000
LWT NN 024/037 021/048 033 14200
    BBBBE 052/030 055/029 051/025 046/024 047 00000000000

&&

.TFX...HIGH WIND WARNING TONIGHT THROUGH SATURDAY MORNING FOR
       THE ROCKY MOUNTAIN FRONT AND THE ADJACENT PLAINS.
    ...WINTER STORM WARNING TONIGHT AND SATURDAY MORNING FOR THE
       ROCKY MOUNTAIN FRONT ABOVE 5000 FEET.
    ...WINTER WEATHER ADVISORY MUCH OF SOUTHWEST MONTANA TONIGHT
       THROUGH SATURDAY MORNING.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
530 AM MST FRI MAR 5 2004

MTZ008>015-044>055-061210-
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-
530 AM MST FRI MAR 5 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST
MONTANA

.DAY ONE...TODAY

...HIGH WIND WARNING IN EFFECT FROM 4 PM THIS AFTERNOON TO 12 PM
SATURDAY FOR THE ROCKY MOUNTAIN FRONT AND THE ADJACENT PLAINS.
PLEASE SEE GTFNPWTFX FOR FURTHER DETAILS.

...WINTER STORM WARNING IN EFFECT FROM 4 PM THIS AFTERNOON TO 12 PM
SATURDAY FOR THE ROCKY MOUNTAIN FRONT ABOVE 5000 FEET. PLEASE SEE
GTFWSWTFX FOR FURTHER DETAILS.

...WINTER WEATHER ADVISORY FOR SNOW AND BLOWING SNOW IN EFFECT FROM
12 AM TO 12 PM SATURDAY FOR MUCH OF SOUTHWEST MONTANA. PLEASE SEE
GTFWSWTFX FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

STRONG WINDS ARE POSSIBLE OVER MUCH OF NORTH CENTRAL MONTANA ON
SUNDAY. THIS AREA IS BEING WATCHED CLOSELY FOR A POSSIBLE HIGH WIND
WATCH OR WARNING.

.SPOTTER INFORMATION STATEMENT...

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