000 FXUS65 KTFX 041005 AFDTFX SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 300 AM MST SAT JAN 4 2003 .SHORT TERM...WINDS HAVE MOSTLY DIED OFF ACROSS MY CWA AS SURFACE HIGH PRESSURE SETTLES OVER THE STATE. THIS HIGH PRESSURE SYSTEM WILL CONTINUE TO MOVE SOUTHEAST TODAY...ALLOWING ANOTHER LEE TROUGH TO FORM IN ALBERTA. DOWNSLOPE WINDS WILL DEVELOP ALONG THE ROCKY MOUNTAIN FRONT BY LATE AFTERNOON AND CONTINUE OVERNIGHT AS ANOTHER VIGOROUS UPPER LEVEL SHORTWAVE SWEEPS ACROSS THE STATE. THE WIND SHOULD REMAIN BELOW HIGH WIND CRITERIA...EXCEPT LOCALLY NEAR CANYONS AND MOUNTAIN PASSES...AND WILL NOT ISSUE ANY HIGHLIGHTS. MID LEVEL FLOW VEERS TO THE NORTHWEST AS THE SYSTEM MOVES THROUGH...ENHANCING UPWARD MOTIONS AS MOIST AIR ENCOUNTERS THE ISLAND RANGES OF CENTRAL MONTANA. HAVE INCREASED CHANCE OF PRECIPITATION ACROSS THE ENTIRE STATE FOR TONIGHT. HAVE ALSO ADDED A CHANCE OF FREEZING RAIN IN THE HAVRE AND HELENA AREAS...MODEL SOUNDINGS INDICATE THAT THIS IS ONLY A SLIGHT CHANCE BUT PREFER TO LEAN TOWARD A CAUTIOUS APPROACH FOR PUBLIC SAFETY CONCERNS. AS THE SHORTWAVE DIVES SOUTH INTO THE FOUR CORNERS REGION...A POSITIVE TILT RIDGE BUILDS OVER THE PACIFIC NORTHWEST. THE BUILDING RIDGE WILL BRING MOSTLY CLEAR TO PARTLY CLOUDY SKIES AND MILD TEMPERATURES TO THE STATE...AND NOT MUCH CHANCE FOR PRECIPITATION. MPJ .EXTENDED...WARM TEMPS AND DRY CONDITIONS WILL BE THE MAIN STORY FOR TUESDAY...AS A MASSIVE UPPER LEVEL RIDGE BUILDS ACROSS THE AREA. TEMPS NEAR 60 ARE A GOOD POSSIBILITY OVER THE PLAINS WITH ABUNDANT SUNSHINE AND UNSEASONABLY WARM AIR ALOFT MIXING DOWN TO THE SURFACE. WITH INVERSIONS TRAPPED IN THE SOUTHWEST VALLEYS...TEMPS WILL ONLY WARM TO AROUND 40. WEDNESDAY...TEMPS WILL COOL DOWN A GOOD 10-15 DEGREES ACROSS THE PLAINS WITH COLD AIR ADVECTION...BUT THE BRUNT OF THE COLD AIR WILL BE SHUNTED OFF TO THE EAST OF MONTANA. I AM LEANING TOWARDS THE GFS SOLUTION...WHICH FORECASTS THE UPPER LEVEL RIDGE TO HANG TOUGH WEDNESDAY...WHILE THE ECMWF ABRUPTLY FLATTENS THE RIDGE. WITH DRY AIR IN PLACE AND VIRTUALLY NO FORCING...WILL TAKE OUT ALL POPS FOR WEDNESDAY. TEMPS COOL A BIT MORE FOR THURSDAY WITH A BETTER NORTHERLY PUSH. WITH SOME INCREASING MOISTURE AND WEAK FORCING...WILL CARRY SLIGHT CHANCE POPS FOR THE CWA. VILLANI .CCF NUMBERS GTF CE 052/035 048/029 051 14030 BBEEE 035/058 033/042 019/032 017/034 017 00000002000 CTB CE 048/033 045/026 050 14020 BBEEE 033/056 033/040 015/031 011/031 011 00000002000 HLN CE 048/029 044/018 041 14-41 BBEEE 020/042 017/036 014/031 015/033 015 00000002000 BZN CE 045/027 042/016 037 14-52 BBEEE 011/040 011/034 010/027 010/030 010 00000002220 WEY JE 032/017 026/004 026 14363 BBEEE 002/032 003/026 002/023 002/024 002 00000002220 DLN CE 044/030 039/014 038 14-41 BBEEE 015/041 018/038 017/028 015/031 015 00000002220 HVR EC 049/031 045/022 047 14032 BBEEE 024/055 024/037 012/027 009/026 009 00000002000 LWT EC 050/033 046/023 050 14032 BBEEE 029/057 029/041 017/032 014/034 014 00000002000 TFX...NONE.