000 FXUS65 KTFX 102209 CCA AFDTFX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MONTANA 248 PM MST MON JAN 10 2005 ...CORRECTED HEADLINES... .DISCUSSION... TONIGHT THROUGH TUESDAY NIGHT...MODELS IN GOOD AGREEMENT WITH SURFACE TROF CONTINUING TONIGHT FOR SOME DOWNSLOPE WINDS AS UPPER LEVEL TROF AND SHORT WAVE MOVE THROUGH NORTH AND CENTRAL ZONES. SHALLOWING OF ARCTIC AIR TONIGHT WILL CONTINUE TUESDAY BUT POCKETS OF COOLER AIR WILL CONTINUE. GUSTY WINDS WILL PICK UP TUESDAY AFTERNOON ESPECIALLY ALONG THE ROCKY MOUNTAIN FRONT AND CAUSE CURRENT SNOW ON GROUND TO BE BLOWN ABOUT. CAMP WEDNESDAY AND WEDNESDAY NIGHT...A VERY STRONG ARCTIC COLD FRONT WILL BE ENTERING NORTH CENTRAL MONTANA WEDNESDAY MORNING AND WILL PUSH INTO CENTRAL MONTANA BY NOON. STRONG WEST WINDS WILL CONTINUE INTO WEDNESDAY MORNING ALONG THE ROCKY MOUNTAIN FRONT BEFORE THE FRONTAL PASSAGE. ONCE THE FRONT PASSES THROUGH EXPECT WINDS TO SHIFT NORTH AND BE QUITE STRONG FOR THREE TO FIVE HOURS. STRONG PRESSURE RISES BEHIND THE FRONT AND A TIGHT PRESSURE GRADIENT WILL PRODUCE WINDS OF 25 TO 35 MPH WITH GUSTS TO 50 MPH WITH THE FRONTAL PASSAGE. IN ADDITION TO THE STRONG WINDS...SNOW WILL ACCOMPANY THE FRONT. ACROSS NORTH CENTRAL MONTANA AND THE NORTHERN PART OF SOUTHWEST MONTANA EXPECT 1 TO 3 INCHES OF NEW SNOW. TEMPERATURES WILL DRASTICALLY DROP BEHIND THE FRONT. WESTERLY DOWNSLOPE WINDS AHEAD OF THE FRONT WILL KEEP TEMPERATURES IN THE TEENS AND 20S ACROSS THE REGION. ONCE THE FRONT PASSES THROUGH TEMPERATURES WILL DROP TO 5 TO 15 BELOW ZERO WITH IN A COUPLE OF HOURS. DUE TO THE STRONG WINDS...NEW SNOWFALL AND THE DANGEROUSLY COLD WIND CHILLS HAVE DECIDED TO ISSUE A BLIZZARD WATCH FOR THE ROCKY MOUNTAIN FRONT AND THE ADJACENT PLAINS. EXPECT A 3 TO 6 HOUR PERIOD OF NEAR ZERO VISIBILITY AFTER THE FRONTAL PASSAGE DUE TO SNOW AND BLOWING SNOW. BY WEDNESDAY EVENING WINDS WILL DECREASE AND CONDITIONS WILL IMPROVE. HOWEVER TEMPERATURES WILL DIP UNDER 20 BELOW ZERO ACROSS NORTH CENTRAL MONTANA. MEIER THURSDAY THROUGH MONDAY...MAIN FOCUS FOR THIS PERIOD WILL BE TEMPERATURES. THE AMPLIFIED RIDGE OF HIGH PRESSURE PRESENT NEAR 150 WEST WILL CONTINUE TO SLOWLY WEAKEN AND SHIFT EAST THROUGH THE PERIOD. MODELS ARE STILL TOO QUICK WITH THE OVERALL PROGRESSION OF LONG WAVE FEATURES...WHICH IS TYPICAL GIVEN THE BREAKDOWN OF A BLOCKING SCHEME. THE GFSLR HAS WAFFLED BACK AND FORTH FOR THE LAST SEVERAL RUNS WITH THE ECMWF AND CANADIAN BEING MORE CONSISTENT. WILL USE THIS MODEL COMBINATION IN THIS FORECAST PACKAGE. AFTER THE ARCTIC FRONTAL PASSAGE ON WEDNESDAY...MODELS TRY TO MODIFY THE AIRMASS TOO QUICKLY BY LATE THIS WEEK. ACTUALLY BELIEVE THAT A SECONDARY COLD FRONT AND SURFACE HIGH WILL DROP DOWN OVER MONTANA LATER FRIDAY INTO SATURDAY. GIVEN THIS THINKING...HAVE DROPPED TEMPERATURES CONSIDERABLY FRIDAY INTO SATURDAY NIGHT. THEN THINK WE WILL GET ENOUGH UPPER LEVEL RIDGING INTO THE REGION FOR A WARMING TREND STARTING SATURDAY NIGHT AND SUNDAY. TEMPERATURES WILL CONTINUE TO WARM INTO NEXT WEEK...WITH SNOW COVER HOLDING A BIG WARMUP DOWN FOR A FEW DAYS. NEVERTHELESS...TEMPERATURES SHOULD CLIMB TO ABOVE NORMAL VALUES BY THE MIDDLE OF NEXT WEEK. SCHAUMANN && .PRELIMINARY POINT TEMPS/POPS... GTF BS 010/029 013/015 923 07002 IIBBB 915/925 908/920 006/902 020/901 020 81000000000 CTB BS 008/028 907/907 932 07005 IIBBB 920/928 912/929 008/000 013/906 013 70000000000 HLN BS 901/025 020/020 910 07102 IIBBB 902/915 907/911 004/907 015/009 015 722--000--- BZN ES 002/025 007/023 907 07-02 BBBBB 003/917 001/915 009/905 015/004 015 76110000000 WEY ES 010/026 008/017 001 07333 BBBBB 005/918 005/919 009/911 020/004 020 643322--111 DLN ES 009/025 012/023 004 07102 BBBBB 010/912 003/910 010/902 020/011 020 63220000000 HVR BS 910/020 005/005 932 07003 IIIUB 925/933 914/933 904/912 009/905 012 60000000000 LWT BS 009/031 016/018 916 07002 IIBBB 913/920 905/917 006/901 019/904 019 82000000000 && .TFX WATCHES/WARNINGS/ADVISORIES... ...BLIZZARD WATCH FOR THE ROCKY MOUNTAIN FRONT AND EASTERN GLACIER COUNTY FOR TUESDAY NIGHT AND WEDNESDAY... ...BLIZZARD WATCH FOR TOOLE...LIBERTY...CHOUTEAU...EASTERN PONDERA EASTERN TETON AND CASCADE COUNTIES FOR WEDNESDAY... ...WINTER STORM WATCH FOR HILL...BLAINE...FERGUS...JUDITH BASIN...SOUTHERN LEWIS CLARK...MEAGHER...BROADWATER AND JEFFERSON COUNTIES FOR WEDNESDAY... && $$