000 FXUS65 KBYZ 221555 AFDBYZ AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BILLINGS MT 854 AM MST MON NOV 22 2004 .SHORT TERM...VALID FOR TDY AND TUE... NO UPDATE NEEDED THIS MORNING. RADAR IMAGERY AND SURFACE OBSERVATIONS INDICATED PRECIPITATION WAS OCCURRING OVER NORTH CENTRAL AND NW MT IN ASSOCIATION WITH THE COLD FRONT WHICH HAD ENTERED FAR NORTHERN MT. DEWPOINTS OVER MUCH OF THE FORECAST AREA WERE IN THE TEENS AND OBSERVED SOUNDINGS SHOWED A DRY AIRMASS BELOW 600 MB. AIRMASS WILL MOISTEN UP FROM WEST TO EAST THIS AFTERNOON AS NW FLOW ALOFT BRINGS MOISTURE INTO THE AREA AND COLD ADVECTION MOVES OVER THE REGION. PRECIPITATION TIMING WAS IN GOOD SHAPE. TEMPERATURES WERE IN THE MID 30S AT 15Z. FORECAST MAXES IN MID TO UPPER 40S SEEMED REASONABLE GIVEN A SEVERAL HOUR PERIOD OF PREFRONTAL WARMING AND CLOUD COVER. STRONG WINDS IN E LOOKED GOOD WITH STRONG COLD ADVECTION PROGGED OVER THIS AREA. ARTHUR .LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN... THE EXTENDED FORECAST WILL BE A BIT TRICKY. THE TRICKINESS WILL INVOLVE WHERE EXACTLY COLD FRONTS WILL LAY ACROSS THE FORECAST AREA. THE EXTENDED MODELS WERE IN GOOD AGREEMENT ON THE UPPER FEATURES THROUGH THE WEEKEND. NORTHWEST FLOW WILL BE REPLACED BY A FLAT UPPER RIDGE FOR WEDNESDAY. WARM AIR ADVECTION WILL BEGIN OVER TOP A COLD FRONT OVER THE AREA. THE COLD AIR SHOULD SHALLOW...WITH SOME LIFT ABOVE AND EAST OF THE BOUNDARY WEDNESDAY NIGHT THROUGH THURSDAY. THE BOUNDARY WILL SHIFT EAST WEDNESDAY NIGHT AND THURSDAY. THE GFS WAS VERY AGGRESSIVE IN QPF FOR THIS TIME. BELIEVE IT IS PROBABLY OVERDONE BUT WOULD AGREE THAT THE PARAMETERS WOULD PRODUCE A CHANCE OF PRECIPITATION. SO HAVE ADDED POPS WEDNESDAY NIGHT AND THURSDAY. A REINFORCING SHOT OF COLD AIR WILL COME THROUGH THURSDAY AFTERNOON AND NIGHT AND DRIVE THE BOUNDARY MENTIONED EARLIER BACK WEST AND SOUTH. DRIER AIR WILL WORK IN BEHIND THE FRONT...BUT SHOULD SEE SOME SHOWERS OVER THE MOUNTAINS. A BROAD TROUGH WILL TAKE SHAPE OVER THE NORTHERN ROCKIES OVER THE WEEKEND. THE GFS EXPECTS THIS FLOW TO BE FAIRLY MOIST...SO MAY NEED TO ADD POPS. WILL HOLD OFF FOR NOW AS DYNAMICS LOOK WEAK AND FOR COORDINATION PURPOSES. HUMPHREY && .PRELIMINARY POINT TEMP/POPS... TDY TUE WED THU FRI SAT SUN ------------------------------------------------------- BIL 048 020/033 018/038 026/046 026/038 023/035 021/036 2/W 63/S 00/E 22/W 00/B 00/B 00/B LVM 045 020/035 017/036 028/045 026/039 020/034 018/032 2/W 73/S 30/N 34/W 20/B 00/B 00/B HDN 046 020/034 018/039 023/046 027/040 021/036 021/037 2/W 42/R 00/B 32/W 00/B 00/B 00/B MLS 045 017/033 012/031 020/044 021/039 019/035 018/034 2/W 20/B 00/B 22/W 00/B 00/B 00/B 4BQ 043 019/033 016/034 021/046 023/041 019/038 019/036 0/N 30/B 00/B 22/W 00/B 00/B 00/B BHK 041 015/029 009/028 017/038 019/034 013/032 012/026 0/N 20/B 00/B 22/W 00/B 00/B 00/B SHR 044 021/032 014/033 018/046 022/038 015/036 014/035 2/W 63/S 30/B 22/W 00/B 00/B 00/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$