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
