Expires:No;;283207 FXUS65 KBYZ 270415 AFDBYZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 915 PM MST THU NOV 26 2009 .SHORT TERM...VALID FOR FRI AND SAT... MADE SOME CHANGES TO THE FORECAST TONIGHT. INCREASED CLOUDS OVER THE AREA TO MOSTLY CLOUDY EVEN THOUGH THEY ARE HIGH BASED. CHINOOK WINDS OFF THE ROCKIES ARE PRODUCING MOST OF THE CLOUD COVER. ALSO...WINDS IN LIVINGSTON HAVE COME DOWN A BIT OVER THE PAST HOUR. THEY FLIRTED WITH WIND ADVISORY LEVELS THIS EVENING BUT DID NOT OFFICIALLY REACH THEM. MODELS DO WEAKEN THE PRESSURE GRADIENT OVERNIGHT AND INTO FRIDAY MORNING THUS THINK THE WINDS WILL NOT INCREASE ANYMORE THAN WHAT WE HAVE SEEN TONIGHT. ALSO INCREASED LOW TEMPS TONIGHT ACROSS THE WEST AND CENTRAL WHERE WINDS ALONG WITH CLOUD COVER SHOULD KEEP TEMPS FAIRLY MILD. UPDATE OUT SHORTLY. SOLUM .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... WARM/DRY/WINDY DAY ON TAP FOR MONDAY AS WEEKEND TROF DEPARTS AND SHORTWAVE RIDGE BUILDS OVER THE NORTHERN ROCKIES IN ADVANCE OF NEXT WAVE EMERGING FROM THE NORTH PACIFIC. DOWNSLOPE GRADIENTS BECOME PRETTY TIGHT SUNDAY NIGHT TO MONDAY NIGHT...AND FLOW WILL LIKELY FLATTEN/BACK ENOUGH FOR GAP WINDS TO DEVELOP AT LVM AND NYE. WINDS SHOULD ALSO BECOME AT LEAST FAIRLY STRONG AT BIG TIMBER AND HARLOWTON DURING THIS PERIOD...LOCATIONS FAVORED BY A MORE WESTERLY WIND. IN ANY EVENT THIS IS A PERIOD TO WATCH FOR WINDS. TEMPS WILL MODERATE QUITE A BIT IN THE DOWNSLOPE REGIME MONDAY. HAVE RAISED EXPECTED TEMPS UP A FEW DEGREES BOTH MONDAY AND MONDAY NIGHT. COLD FRONT LOOKS TO MOVE INTO THE AREA TUESDAY. CLIPPER AND PASSAGE OF COLD FRONT ON TUESDAY WILL BEGIN A TRANSITION TO A COLDER FEW DAYS...AT LEAST...AS N-NW FLOW SETS UP OVER THE REGION AND RIDGE AXIS AMPLIFIES ALONG THE PACIFIC COAST. MODELS VERY SCATTERED IN LOCATION/DEPTH OF COLD UPPER LOW WHICH LOOKS TO THEN SETTLE OVER THE UPPER MIDWEST AND GREAT LAKES...THUS ITS DIFFICULT TO DETERMINE HOW SIGNIFICANT THE COLD SURGE WILL BE IN EASTERN MONTANA. LATEST GFS IS DRIER AND A BIT WARMER WITH HIGHER HEIGHTS THAN THE ECMWF/UKMET...AND 12Z GFS ENSEMBLES GENERALLY GIVE SUPPORT TO THE OPERATIONAL RUN. EC/UK SHOW MUCH DEEPER AND COLDER CYCLONIC FLOW OVER US. GIVEN SUCH VARIABILITY HAVE OPTED TO KEEP CHANCES OF PCPN RESTRICTED TO TUESDAY INTO TUESDAY NIGHT...AS INHERITED WITH PASSAGE OF INITIAL SHORTWAVE... AND KEEP THE PLAINS DRY WED/THU AS GFS SUGGESTS. THIS WOULD BE SUBJECT TO CHANGE IF THE GFS TRENDS THE OTHER DIRECTION... ESPECIALLY IN NW FLOW FAVORED AREAS. HAVE DROPPED TEMPS SEVERAL DEGREES IN OUR EAST WED/THU WHERE COLD AIR WILL BE DEEPEST...AND SHOULD AT LEAST SEE A COUPLE DAYS OF BELOW NORMAL TEMPS. THOUGH AT THIS TIME DO NOT SEE ANY SIGNIFICANT PCPN DURING THE TUE-THU PERIOD...WE SHOULD SEE TEMPS RETURN TO A MORE WINTRY LEVEL. JKL && .AVIATION... STRONG GUSTY SOUTHWEST WINDS IN THE WEST...ALONG THE EASTERN MOUNTAIN SLOPES...CONTINUE TO BE THE ONLY AVIATION ISSUE OVERNIGHT. GUSTS OF 35-45 KTS AT KLVM CAN BE EXPECTED...WITH WINDS REMAINING GUSTY AROUND KLVM THROUGH FRIDAY. VFR CONDITIONS WILL PREVAIL ACROSS THE REGION OVERNIGHT...UNDER SCATTERED TO BROKEN HIGH CLOUDS...THROUGH TOMORROW MORNING. THE BEARTOOTH MOUNTAINS ARE EXPECTED TO SEE SOME LIGHT SNOW TOMORROW AFTERNOON...AS A PACIFIC SYSTEM APPROACHES...RESULTING IN POSSIBLE MOUNTAIN OBSCURATION. GILSTAD && .PRELIMINARY POINT TEMP/POPS... FRI SAT SUN MON TUE WED THU ----------------------------------------------------------- BIL 038/054 031/039 024/040 025/051 028/040 023/031 018/029 00/B 22/W 20/B 00/N 12/J 11/B 11/B LVM 038/049 021/034 015/038 026/046 026/037 019/029 013/027 02/W 32/J 21/B 00/N 23/J 11/B 11/B HDN 031/056 031/042 023/043 020/052 023/044 020/033 017/032 00/B 22/W 21/B 00/U 12/J 11/B 11/B MLS 027/056 032/041 022/040 020/051 022/040 020/033 017/031 00/B 22/W 21/B 00/U 12/J 11/B 11/B 4BQ 031/058 031/040 022/040 020/049 022/042 020/032 015/029 00/B 22/W 21/B 00/U 02/J 11/B 11/B BHK 027/054 030/039 022/035 017/045 021/039 019/031 013/027 00/U 22/W 21/B 00/B 02/J 11/N 11/B SHR 027/056 028/041 018/041 015/054 022/040 019/031 016/029 00/B 23/W 21/B 00/U 02/J 21/B 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS