364 FXUS65 KTFX 060432 AFDTFX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 932 PM MST WED DEC 5 2012 .UPDATE... CURRENT FORECAST LOOKS ON TRACK...WITH NO MAJOR CHANGES THIS EVENING. THE STRONG WINDS FROM EARLIER TODAY HAVE DIMINISHED OVER THE REGION AND A SUMMARY LSR HAS BEEN SENT. A FEW LIGHT RAIN/SNOW SHOWERS CONTINUE OVER FAR SOUTHWEST MONTANA...MAINLY IN THE WEST YELLOWSTONE AREA THIS EVENING. OTHER SCATTERED LIGHT SNOW SHOWERS/FLURRIES ARE CURRENTLY FALLING OVER THE ROCKY MOUNTAIN FRONT. THUS...OTHER THAN THESE REGIONS...POPS HAVE GENERALLY BEEN LOWERED A BIT. OVERNIGHT LOWS LOOK ON TRACK. LOOKING AHEAD...THERE COULD BE A BRIEF PERIOD OF STEADIER LIGHT SNOW ON THURSDAY MORNING WHERE AN INCH OR TWO OF SNOW ACCUMULATION WILL BE POSSIBLE. AN INCH OR SO IS ALSO POSSIBLE ALONG THE DIVIDE OVER THE ROCKY MOUNTAIN FRONT. OTHERWISE...MAINLY COOLER TEMPERATURES AND JUST SCATTERED SNOW SHOWERS ARE POSSIBLE OVER THE REGION. THE COOL AND UNSETTLED WEATHER CONTINUES INTO FRIDAY. THE MAIN COLD FRONT FOR THE WEEKEND MOVES SOUTHWARD THROUGH THE REGION FRIDAY NIGHT AND SATURDAY. A BAND OF LIGHT SNOW IS EXPECTED TO ACCOMPANY THIS FRONTAL PASSAGE. RIGHT NOW...SNOW ACCUMULATIONS OF AN INCH OR TWO SEEM POSSIBLE AT LOWER ELEVATIONS WITH 3 TO 5 INCHES POSSIBLE IN THE MOUNTAINS. BRUSDA && .AVIATION... UPDATED 2345Z. STRONG AND GUSTY SURFACE WINDS WILL SLOWLY DECREASE THROUGH 06Z AS AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT CONTINUE TO MOVE AWAY FROM THE AREA. A FEW ISOLATED RAIN/SNOW SHOWERS WILL CONTINUE IN THE WAKE OF THE COLD FRONT PASSAGE BUT SHOULD END BY 04Z. VFR CONDITIONS PREVAIL WITH MVFR CONDITIONS POSSIBLE IN THE VICINITY OF SHOWERS. && .PREV DISCUSSION... /ISSUED 615 PM MST WED DEC 5 2012/ TONIGHT THROUGH FRIDAY...STRONG WESTERLY WINDS WILL CONTINUE TO MIX DOWN TO THE SURFACE ALONG AND BEHIND THE PACIFIC COLD FRONT AS IT MOVES EAST THROUGH NORTH CENTRAL AND SOUTHWEST MONTANA THIS AFTERNOON. SURFACE WINDS WILL DECREASE EARLY THIS EVENING AS THE SURFACE GRADIENT RELAXES AND WINDS ALOFT DECREASE. WILL THEREFORE CONTINUE WITH THE HIGH WIND WARNINGS FOR THE ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS AND NORRIS HILL...AND WILL KEEP AN EYE ON THE EASTERN TFX PLAINS AS THE FRONT PASSES. OVERALL...PRECIPITATION HAS BEEN DECREASING AS WELL...WITH ONLY LINGERING CONVECTIVE SHOWERS IN THE MOUNTAINS. TEMPERATURES ARE LIKELY TO STAY ABOVE FREEZING FOR THE REMAINDER OF THE AFTERNOON IN THE WEST YELLOWSTONE/RAYNOLDS PASS/TARGHEE PASS AREAS OF FAR SOUTHWEST MONTANA...AS LINGERING SHOWERS CONTINUE TO DIMINISH. THEREFORE...WILL CANCEL THE WINTER WEATHER ADVISORY FOR THERE...AS TRAVEL CONDITIONS SHOULD NOT BE QUITE AS HAZARDOUS NOW. LINGERING CLOUDS IN THE MOUNTAIN AREAS AND BREEZY PLAINS WINDS SHOULD KEEP TEMPERATURES FROM DROPPING SIGNIFICANTLY BELOW SEASONAL AVERAGES...BUT SOME HIGHER VALLEYS MAY STILL NEED TO BE MONITORED. A MOIST CYCLONIC WESTERLY FLOW ALOFT WILL THEN DEVELOP OVER THE AREA THURSDAY THROUGH FRIDAY...LIKELY BRINGING LIGHT MEASURABLE SNOWFALL TO THE MOUNTAINS. WEAK DISTURBANCES MOVING THROUGH THE AREA WILL ALSO KEEP THE AIRMASS SLIGHTLY UNSTABLE DURING THE AFTERNOON HOURS...WHICH WILL KEEP A GOOD CHANCE OF SHOWERS IN THE SOUTHWEST VALLEYS. OVER THE PLAINS...THE CHANCE FOR SHOWERS WILL BE LOWER...AS BREEZY WESTERLY DOWNSLOPE WINDS PERSIST THROUGH THE PERIOD. AM NOT EXPECTING SNOW AMOUNTS TO BE HEAVY ENOUGH TO WARRANT WINTER WEATHER HIGHLIGHTS AT THIS TIME. DAYTIME HIGHS WILL REMAIN NEAR SEASONAL AVERAGES...BUT CLOUD COVER WILL KEEP OVERNIGHT LOWS SLIGHTLY ABOVE NORMAL. COULSTON FRIDAY NIGHT THROUGH WEDNESDAY...INDIVIDUAL EXTENDED RANGE FORECAST MODELS AND MODEL ENSEMBLES IN GOOD AGREEMENT THAT A COOL AND UNSETTLED NORTHWEST FLOW PATTERN WILL BE IN PLACE FOR MOST OF THIS PERIOD. SHORTWAVE TROFS EMBEDDED IN THE FLOW WILL PASS THROUGH OUR REGION ABOUT EVERY OTHER DAY BEGINNING ON SATURDAY...WITH EACH SYSTEM BRINGING A CHANCE OF LIGHT SNOW TO THE MOUNTAINS AND PLAINS. THE FIRST SYSTEM THIS WEEKEND WILL ALSO USHER IN THE COLDEST TEMPERATURES OF THE PERIOD AS A CANADIAN COLD FRONT SWEEPS SOUTHWARD. HIGHS SATURDAY SHOULD ONLY REACH THE TEENS OVER THE HI-LINE AND THE SOUTHWEST VALLEYS AND LOW 20S OVER THE CENTRAL COUNTIES. WITH ABOUT AN INCH OF FRESH SNOW EXPECTED IN THE LOWER ELEVATIONS AND GRADUALLY CLEARING SKIES SAT NIGHT...OVERNIGHT LOWS WILL DROP TO THE SINGLE DIGITS FOR MUCH OF THE REGION WITH SOME HI-LINE LOCATIONS REACHING A FEW DEGREES BELOW ZERO. AS THE FIRST SHORTWAVE EXITS...THE STRONG UPPER LEVEL RIDGE OVER THE ERN PACIFIC WILL AMPLIFY SLIGHTLY OVER THE NRN ROCKIES AND BRING A BRIEF PERIOD OF WARMER DOWNSLOPE CONDITIONS SUN EVE BUT THE NEXT SYSTEM FOLLOWS QUICKLY ON MON. RIGHT NOW ITS ACCOMPANYING AIRMASS DOES NOT APPEAR TO BE A COLD AS THE WEEKEND SYSTEM THOUGH HIGH TEMPS WILL ONLY MAKE IT TO THE MID 30S...WHICH IS RIGHT AT THE SEASONAL AVERAGE FOR EARLY DEC. GFS AND EUROPEAN MODELS DIVERGE SOMEWHAT ON TUES WITH THE GFS EXPANDING THE UPPER RIDGE EASTWARD AND KEEPING US DRY...WHILE THE EUROPEAN DROPS ANOTHER SHORTWAVE TROF ACROSS THE STATE WITH SCATTERED LIGHT SNOW. MODELS COME BACK TO SIMILAR SOLUTIONS ON WED WITH A SLIGHTLY SHARPER AND COOLER TROF MOVING ACROSS THE PACIFIC NW AND NRN ROCKIES AND MORE LIGHT SNOW. TEMPERATURES SHOULD REACH THE MID- UPPER 30S AROUND MIDDAY BEFORE ANOTHER COLD FRONT ARRIVES WED AFTN/EVE. WARANAUSKAS && .PRELIMINARY POINT TEMPS/POPS... GTF 27 37 26 36 / 0 20 20 20 CTB 24 33 20 31 / 0 20 10 20 HLN 25 35 22 35 / 10 40 30 30 BZN 25 35 20 34 / 20 40 40 30 WEY 25 31 17 26 / 60 50 60 50 DLN 26 34 20 33 / 20 40 40 30 HVR 23 32 21 29 / 0 10 20 30 LWT 24 34 20 33 / 10 20 20 30 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ WEATHER.GOV/GREATFALLS