FXUS65 KBYZ 270138
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
638 PM MST THU NOV 26 2009
.SHORT TERM...VALID FOR FRI AND SAT...
QUICK UPDATE TO INCREASE WINDS IN THE LIVINGSTON AREA AS WINDS
GUSTING UP TO 52 MPH. WILL CONTINUE TO MONITOR TO SEE IF WINDS
WILL GET STRONGER AS THE NIGHT GOES ON AND IF ANY HIGHLIGHTS WILL
BE NEEDED. SOLUM
...PREVIOUS DISCUSSION...
MADE A FEW ADJUSTMENTS TO SHORT-TERM FORECASTS. UPPER-LEVEL RIDGE
WILL PERSIST OVER THE REGION THROUGH FRIDAY. DRY CONDITIONS WILL
PREVAIL. PERSISTENT CLOUD COVER HAMPERED WARMING THIS AFTERNOON
OVER WESTERN AND CENTRAL ZONES. MOSTLY CLEAR SKIES OVER EASTERN
ZONES ALLOWED TEMPERATURES TO WARM INTO THE LOW TO MID 60S. THE
NEXT UPPER-LEVEL TROUGH WILL FLATTEN THE RIDGE FOR FRIDAY. GUSTY
WINDS ALONG THE BEARTOOTH FOOTHILLS SHOULD CONTINUE OVERNIGHT
THROUGH MID-MORNING FRIDAY. PRESSURE FALLS WILL ERODE THE HIGH
PRESSURE OVER THE INTER-MOUNTAIN WEST WHILE PRESSURES RISE BEHIND
AN APPROACHING COLD FRONT. SLIGHTLY COOLER TEMPERATURES ARE
EXPECTED WITH DRY CONDITIONS THROUGHOUT THE DAY. THE UPPER TROUGH
APPROACHES THE CWA LATE FRIDAY INTO EARLY SATURDAY. KEPT SLIGHT
CHANCE POPS OVER WESTERN ZONES FOR LATE FRIDAY BEFORE SPREADING
POPS EASTWARD DURING SATURDAY. THE TROUGH SPLITS WITH THE BULK OF
THE ENERGY DIVING SOUTHWARD ACROSS THE CONUS. THEREFORE...THE
GREATEST Q-G FORCING REMAINS NORTH AND SOUTH OF THE CWA. A COLD
FRONT WILL PUSH THROUGH THE CWA EARLY SATURDAY. THE GFS DEPICTS
ONLY MODEST FRONTOGENESIS WITH THIS COLD FRONT. THEREFORE...BROAD
BRUSHED LOW POPS ACROSS THE CWA FOR SATURDAY AS WIDELY SCATTERED
PRECIPITATION IS EXPECTED. 850-MB TEMPS FALL INTO THE SINGLE
DIGITS BELOW 0 FOR SATURDAY. COOLED MAX TEMP FORECASTS A BIT IN
RESPONSE. A MOISTLY NLY FLOW PERSISTS OVER THE REGION INTO EARLY
SUNDAY. LINGERED LOW POPS OVER THE CWA GIVEN EMBEDDED VORTICITY
WITHIN THE FLOW. SCHUKNECHT
.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...
ONLY AVIATION ISSUE TONIGHT IS WIND ALONG THE EASTERN SLOPES OF
THE MOUNTAINS. LOOK FOR GUSTS OF 35-45 KTS AT KLVM. WINDS WILL
REMAIN GUSTY AT KLVM THROUGH FRIDAY.
SCATTERED TO BROKEN HIGH CLOUDS AND VFR CONDITIONS WILL IMPACT THE
FORECAST AREA TONIGHT AND FRIDAY MORNING. AN APPROACHING PACIFIC
SYSTEM WILL SPREAD SOME LIGHT SNOW TO THE BEARTOOTH MTNS BY
AFTERNOON...THUS MOUNTAIN OBSCURATIONS ARE POSSIBLE.
JKL
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 034/054 031/039 024/040 025/051 028/040 023/031 018/029
00/B 22/W 20/B 00/N 12/J 11/B 11/B
LVM 025/049 021/034 015/038 026/046 026/037 019/029 013/027
02/W 32/J 21/B 00/N 23/J 11/B 11/B
HDN 034/056 031/042 023/043 020/052 023/044 020/033 017/032
00/B 22/W 21/B 00/U 12/J 11/B 11/B
MLS 032/056 032/041 022/040 020/051 022/040 020/033 017/031
00/B 22/W 21/B 00/U 12/J 11/B 11/B
4BQ 030/058 031/040 022/040 020/049 022/042 020/032 015/029
00/U 22/W 21/B 00/U 02/J 11/B 11/B
BHK 031/054 030/039 022/035 017/045 021/039 019/031 013/027
00/U 22/W 21/B 00/B 02/J 11/N 11/B
SHR 032/056 028/041 018/041 015/054 022/040 019/031 016/029
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
