000 FXUS65 KTFX 040339 AFDTFX SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 830 PM MST TUE DEC 3 2002 CORRECTED CCF NUMBERS WILL UPDATE ZONES AND STATE FORECAST .SHORT TERM...A 500 MB JET STREAK IS MOVING OVER THE FORECAST AREA THIS EVENING. DYNAMICS ASSOCIATED WITH THIS FEATURE HAVE PUSHED THE BAND OF SNOW SOUTH OF GREAT FALLS A LITTLE EARLIER THAN ANTICIPATED. SATELLITE IMAGERY IS IN GOOD AGREEMENT WITH 00Z MODEL INITIALIZATION. IT APPEARS THAT A VERY WEAK 700 MB SHORTWAVE RIDGE WILL RIDE OVER THE AREA BY MIDNIGHT. THE APPROACHING WAVE IS ALREADY APPARENT ON 88-D IMAGERY PUSHING THE SNOW BAND BACK TO THE NORTH NEAR THE CONTINENTAL DIVIDE. THIS BAND WILL CONTINUE TO OSCILLATE OVER CENTRAL MONTANA THIS EVENING FOR SCATTERED SNOW. AFTER MIDNIGHT UPPER LEVEL DYNAMICS SHIFT SOUTH...AWAY FROM THE BEST FRONTO-GENETIC FORCING...AND LOW LEVEL WINDS BECOME LESS UPSLOPE. IN SHORT...SNOWFALL SHOULD DISSIPATE TO ONLY SCATTERED FLURRIES AFTER MIDNIGHT. EXPECT THAT LOW CLOUDS WILL LINGER OVER MUCH OF THE CWA...WITH THE POSSIBLE EXCEPTION OF MY FAR NORTHEAST ZONES WHERE PARTIAL CLEARING MAY OCCUR. COLD ADVECTION DOES NOT LOOK AS STRONG AS PREVIOUSLY ADVERTISED...AND CLOUDS WILL LIKELY KEEP TEMPERATURES FROM PLUMMETING. WILL RAISE OVERNIGHT LOWS AT MOST LOCATIONS...ESPECIALLY IN THE SOUTHWEST WHERE ARCTIC AIR HAS FAILED TO MOVE IN. MPJ .EXTENDED...A WEAK SHORTWAVE/COLD FRONT CONTINUES TO MOVE THROUGH THE STATE FIRDAY NIGHT INTO SATURDAY. MODELS IN DECENT AGREEMENT DEVELOPING DOWNSLOPE GRADIENTS OVER THE PLAINS SUNDAY THROUGH TUESDAY. UPPER LEVEL RIDGE IS NOW STUCK FIRMLY OVER THE WEST COAST... SO NO REAL INCREASE IN THICKNESS VALUES. CURRENT GRADUAL WARMING TREND OVER THE PLAINS...WITH COLD AIR LINGERING IN THE SOUTHWEST VALLEYS...LOOKS GOOD. NO MAJOR CHANGES TO CURRENT EXTENDED PACKAGE. MPJ .CCF NUMBERS GTF EB 003/023 014/035 018 07300 BEBBB 037/017 030/015 036/018 034/020 036 00022000000 CTB EB 902/020 008/033 016 07100 BEBBB 036/014 027/012 032/016 033/018 035 00000000000 HLN EB 013/026 014/025 015 072-0 BEBBE 029/015 031/013 032/016 032/017 034 00022000000 BZN MB 015/022 010/026 013 07222 BEBBB 024/009 028/009 029/010 031/011 033 00033000000 WEY MB 014/022 012/024 008 07222 BEBBB 018/005 022/004 023/006 027/007 029 00233220000 DLN EB 020/030 010/030 013 07112 BBBBE 028/014 028/014 028/014 029/015 031 00033000000 HVR BB 904/020 004/030 013 07000 BEBBB 036/015 025/011 029/015 034/017 036 00000000000 LWT EB 004/021 009/032 016 07400 BEBBB 033/016 027/014 031/017 032/019 034 00022000000 .TFX...NONE.