High Wind in Montana, February 2, 2001

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 AM MST FRI FEB 2 2001

PRIMARY PROBLEM IS WIND DEVELOPMENT TODAY. MODELS SHOW 700 MB WINDS OF
55 TO 60 KTS DEVELOPING OVER THE NORTHWESTERN PLAINS EAST OF THE DIVIDE
LATER THIS MORNING THROUGH EARLY THIS EVENING...AS SHORTWAVE PUSHES
NORTHEASTWARD OVER WASHINGTON AND INTO NORTHWESTERN MONTANA. SHORTWAVE
FOLLOWING THE TRACK REPRESENTED BY THE ETA...AND WILL GO WITH THAT MODEL
FOR THE FORECAST. BACK TO THE WINDS...WILL UPGRADE HIGH WIND WATCH
CURRENTLY OUT TO A WARNING...BUT WILL START WARNING LATER THIS MORNING
FOR THE ROCKY MOUNTAIN FRONT AND COUNTIES ALONG THE WESTERN HI-LINE AS
WINDS THERE HAVE STAYED UP ALL NIGHT AND WILL NOT TAKE MUCH TO REACH
HIGH WIND CRITERIA. CASCADE AND EASTERN TETON COUNTIES...HOWEVER...
SHOULD NOT SEE THESE HIGH WINDS UNTIL THIS AFTERNOON. SIGNIFICANT
MOISTURE AHEAD OF SHORTWAVE TO BRING OCCASIONAL SNOW TO THE ROCKY
MOUNTAIN FRONT MOUNTAINS. HOWEVER...TRACK OF SHORTWAVE WILL KEEP SNOW
FAIRLY LIMITED IN SOUTHWESTERN MONTANA AND WILL LEAVE ONLY SCATTERED
POPS. SUBSIDENCE ASSOCIATED WITH STRONG WINDS ALOFT TO PREVENT
PRECIPITATION ACROSS THE HIGH WIND WARNING AREA...BUT UPWARD MOTION AT
MID LEVELS OUTSIDE OF THE WARNING AREA WILL KEEP A SLIGHT CHANCE OF
PRECIPITATION ALONG THOSE PLAINS AREAS THIS AFTERNOON AS THE SHORTWAVE
PASSES. WITH THE MOISTURE GREATLY DIMINISHING ALONG THE PLAINS OVERNIGHT
WITH CONTINUED DOWNSLOPE...WILL GO WITH VARIABLE CLOUDINESS EARLY
TONIGHT AND PARTLY CLOUDY THROUGH SATURDAY. LINGERING MID LEVEL MOISTURE
WILL KEEP SOUTHWEST MONTANA AND THE ROCKY MOUNTAIN FRONT MOSTLY CLOUDY.
SNOW WILL BE LIKELY OVER THE ROCKY MOUNTAIN FRONT MOUNTAINS AS ENERGY
CONTINUES TO STREAM OVER THE AREA IN A WESTERLY FLOW ALOFT.
HOWEVER...ONLY ISOLATED SNOW IS EXPECTED IN THE SOUTHWEST WITH A LACK OF
DYNAMICS. A PLUME OF MOISTURE THEN THREATENS THE SOUTHWEST ON SATURDAY
FOR CONTINUED ISOLATED SNOW. TEMPERATURES TODAY WILL GENERALLY BE A
LITTLE WARMER THAN YESTERDAY...BUT MUCH WARMER IN THE NORTHEASTERN TFX
ZONES AS THE COLD AIR THERE HAS MOVED OUT. A COLD FRONT ACCOMPANIES THE
SHORTWAVE...AND WILL COOL TEMPERATURES SOMEWHAT FOR TONIGHT AND
SATURDAY...DESPITE CONTINUED DOWNSLOPE WINDS ALONG THE PLAINS.

EXTENDED...NEW AVN AND MRF SEEM TO RESOLVE SITUATION SIMILARLY WITH MORE
OF A NORTHWESTERLY FLOW DEVELOPING ON SUNDAY AND MONDAY AND A WEAK
SHORTWAVE MOVING OVER THE STATE. ALSO...SURFACE HIGH PRESSURE SEEMS TO
NOSE INTO THE STATE FROM THE NORTHWEST FOR A DEVELOPING WEAK UPSLOPE.
HOWEVER...MOISTURE IS SOMEWHAT LIMITED WITH THESE MODELS. ECMWF KEEPS
WESTERLY FLOW ALOFT OVER CWA THROUGH THIS PERIOD...HINTING TOWARD
CURRENT FORECAST OF DRY OVER THE PLAINS WITH WEST WINDS AT TIMES. AM
LEANING TOWARD NEW AVN AND MRF AND WILL INTRODUCE A CHANCE OF
PRECIPITATION OVER THE PLAINS FOR SUNDAY AND MONDAY WITH NO MENTION OF
WINDS...EXCEPT ALONG THE ROCKY MOUNTAIN FRONT AND THE IMMEDIATE PLAINS.
OTHERWISE...ALL MODELS GOING WITH THE RIDGE BUILDING OFF THE PACIFIC
COAST WITH A COOLER NORTHWESTERLY TO NORTHERLY FLOW ALOFT WITH
INCREASING MOISTURE AND A SERIES OF COLD FRONTS. THEREFORE...WILL LEAVE
LATER PERIODS AS IS.

COULSTON

CCF NUMBERS
GTF NB 050/027 042/020 035 10100
CTB NB 047/024 038/016 032 10100
HLN EE 045/022 038/018 038 10211
BZN EE 041/020 035/015 035 10211
WEY EE 032/005 025/905K 025 10322
DLN EE 040/018 035/015 035 10211
HVR NB 045/023 038/018 033 10110
LWT NB 045/025 039/020 035 10110