539
FXUS65 KBYZ 211451
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
751 AM MST FRI NOV 21 2025
KEY MESSAGES
- DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES (+10 TO 15 DEG)
CONTINUE THROUGH THE WEEKEND.
- BREEZY TO LOCALLY GUSTY (25-40MPH) WINDS FOR THE WESTERN
FOOTHILLS THIS WEEKEND; A PERIOD OF STRONGER WINDS POSSIBLE
MONDAY ACROSS THE AREA.
- A SIGNIFICANT PATTERN CHANGE IS COMING EARLY NEXT WEEK, WITH
BELOW NORMAL TEMPERATURES AND THE POTENTIAL FOR PERIODS OF LIGHT
SNOW MONDAY NIGHT THROUGH THE HOLIDAY WEEK.
- BE PREPARED FOR WINTRY IMPACTS TO HOLIDAY TRAVEL NEXT WEEK AND
THROUGH NEXT WEEKEND. MONITOR THE FORECAST!
UPDATE
AREAS OF STRATUS & FOG CONTINUE TO IMPACT THE EAST, MAINLY EAST OF
THE TONGUE RIVER, AS DRIER DOWNSLOPE WINDS HAVE INCREASED OVER THE
WEST. BIG TIMBER IS IN FACT GUSTING TO 38 MPH OUT OF THE WEST AS
OF 735AM. HAVE EXPANDED SKY COVER AND FOG OVER OUR EAST THRU 18Z,
AND TWEAKED UP WINDS IN PARTS OF THE WEST. OTHERWISE WE'LL SEE DRY
CONDITIONS AND TEMPS INTO THE 50S TODAY, ALONG WITH BREEZY WINDS
ALONG THE WESTERN FOOTHILLS. JKL
DISCUSSION
TODAY THROUGH FRIDAY...
SYNOPTIC PATTERN STARTS OFF WITH WEST TO EAST ORIENTED RIDGING
OVER THE AREA TODAY WITH THE AREA SANDWICHED BETWEEN AN UPPER LOW
NORTH OF THE GREAT LAKES AND ANOTHER OFF THE CENTRAL CALIFORNIA
COAST. THIS WILL KEEP DRY CONDITIONS IN PLACE WITH TEMPERATURES
CLIMBING A GOOD 10 DEGREES ABOVE NORMAL. EXPECT WINDS TO GET A BIT
GUSTY (25 TO 40MPH) OVER THE WESTERN FOOTHILLS TODAY. ENERGY FLOWS
ACROSS SOUTHWEST CANADA AND INTO THE LOW NORTH OF THE GREAT LAKES
TONIGHT WHICH SAGS THE RIDGE AXIS SOUTHWARD AND ALLOWS FOR FASTER
ZONAL FLOW ALOFT TO CREEP SOUTHWARD OVER THE AREA SATURDAY AND
SUNDAY. THIS STRONGER DOWNSLOPE AND MIXED WINDS WILL BOOST
TEMPERATURES INTO THE MID 50S TO LOWER 60S EACH AFTERNOON, EVEN
INTO SOUTHEAST MONTANA, WHILE KEEPING DRY CONDITIONS IN PLACE. SO,
THE WEEKEND LOOKS LIKE A GOOD TIME TO GET OUTSIDE AND ENJOY SOME
WARM FALL CONDITIONS, WITH PERIODS OF BREEZY TO GUSTY WINDS THROWN
IN AT TIMES.
MONDAY LOOKS LIKE A TRANSITION DAY WITH A COUPLE OF FRONTS (FIRST
PACIFIC, THEN CANADIAN) POISED TO MOVE THROUGH THE AREA. A LATER
ARRIVAL WILL ALLOW TEMPERATURES INTO THE 50S WHILE AN EARLIER
ARRIVAL MEANS LOWER 40S AND EVEN SOME 30S POSSIBLE FOR HIGHS.
CURRENT NBM FORECAST IS ADVERTISING A MIDDLE GROUND IN THE MID
40S. ENSEMBLES ARE ADVERTISING GUSTY WINDS MONDAY ASSOCIATED WITH
THE TWO FRONTAL PASSAGES WITH GUSTS IN THE 30-40MPH RANGE ACROSS
THE FORECAST AREA. WIND GUSTS WILL BE ON THE STRONGER END OF
GUIDANCE IF THE FRONTAL PASSAGES OCCUR DURING THE MID AFTERNOON
HOURS.
PRECIPITATION CHANCES (20-50 PERCENT; HIGHEST IN THE MOUNTAINS)
INCREASE OVER THE WESTERN MOUNTAINS IN THE EARLY MORNING HOURS
MONDAY, AND LEAK INTO THE ADJACENT FOOTHILLS BY SUNRISE. 20-30
PERCENT CHANCES CONTINUE EASTWARD INTO THE AFTERNOON GIVING JUST
ABOUT EVERYONE AT LEAST A CHANCE TO SEE SOME LIGHT PRECIPITATION
(GENERALLY LESS THAN A TENTH OF AN INCH) MONDAY INTO MONDAY NIGHT,
TAPERING OFF TO A 20% CHANCE TUESDAY MORNING OVER THE MOUNTAINS
AND SOUTHEAST MONTANA. SNOW LEVELS DROP TO AROUND 3000 FEET BY
MONDAY EVENING ACCORDING TO THE NBM, WITH SNOW AT ALL ELEVATIONS
BY MIDNIGHT.
TUESDAY THROUGH THE REST OF THE HOLIDAY WEEK IS MORE UNCERTAIN.
TEMPERATURES WILL DROP MAINLY INTO THE 30S FOR HIGHS DURING THE
PERIOD, THE MOST CONSISTENT WEATHER ELEMENT IN THE FORECAST. FOR
THE OTHER ELEMENTS, THE DETERMINISTIC GFS BOMBS OUT A HUGE UPPER
LOW OVER THE WESTERN DAKOTAS EARLY TUESDAY MORNING RESULTING IN
STRONG (40-60MPH) WINDS TUESDAY ALONG WITH WRAP AROUND SNOW ACROSS
THE EASTERN HALF OF THE FORECAST AREA. THE DETERMINISTIC EC HAS
AN OPEN TROF CROSSING THE AREA WITH GUSTY WINDS BUT LITTLE IN THE
WAY OF SNOWFALL TO CAUSE TRAVEL ISSUES. BOTH SETS OF ENSEMBLES
HAVE A SIGNAL FOR STRONG WINDS AND SOME MEMBERS SHOWING
SIGNIFICANT SNOWFALL, BUT THE MEAN SNOWFALL IS MUTED BY NUMEROUS
MEMBERS SHOWING LITTLE TO NO SNOWFALL. THE CANADIAN HAS BEEN THE
MOST CONSISTENT OF THE MODEL GROUPS OVER THE PAST WEEK OR SO AND
IS SIMILAR TO THE ECMWF SOLUTIONS OVERALL WITH AN OPEN WAVE, GUSTY
WINDS BUT LIGHT SNOWFALL POTENTIAL. IF THE MODELS TREND TOWARD
THE DETERMINISTIC GFS TRAVEL EAST OF BILLINGS INTO THE DAKOTAS
WOULD BE SIGNIFICANTLY IMPACTED FROM LATE MONDAY NIGHT THROUGH
WEDNESDAY MORNING SO STAY TUNED IF YOU HAVE TRAVEL PLANS HEADING
EAST.
WEDNESDAY INTO THURSDAY SOME MID LEVEL OVER-RUNNING DEVELOPS
BRINGING A 10 TO 30 PERCENT CHANCE FOR LIGHT SNOW OR FLURRIES,
SPREADING FROM THE WEST WEDNESDAY AFTERNOON ACROSS THE REST OF THE
FORECAST AREA THURSDAY. AT THIS TIME THIS DOESN'T LOOK TO PRESENT
MUCH OF A TRAVEL CONCERN EAST OF THE DIVIDE. STRONGER CHANCES FOR
SNOW EXIST WEST OF THE DIVIDE FOR THOSE TRAVELING WED/THU.
MODELS ARE STARTING TO ADVERTISE A SURGE OF SIGNIFICANTLY COLDER
AIR FOR NEXT WEEKEND, ALONG WITH PROLONGED OVER-RUNNING SNOW
SCENARIO. A FEW ENSEMBLES ARE LOOKING AT TEMPERATURES WELL BELOW
ZERO FOR HIGHS BY SUNDAY WITH BITTER COLD OVERNIGHT LOWS. THIS
COULD PRESENT A BIGGER THREAT TO HOLIDAY TRAVEL AFTER THANKSGIVING
THAN PRIOR TO IT.
ANY WINTRY WEATHER NEXT WEEK WILL HAVE OBVIOUS IMPACTS TO
THANKSGIVING TRAVEL. IT IS POSSIBLE THAT THE BIGGEST IMPACTS MAY
BE ASSOCIATED WITH A WINTER STORM AND COLD TEMPS NEXT WEEKEND.
THERE REMAINS A LOT OF UNCERTAINTY SO PLEASE MONITOR THE FORECAST
THROUGH THE WEEKEND! CHAMBERS
AVIATION
FOG AND LOW STRATUS CONTINUE ACROSS SOUTHEASTERN MT THIS MORNING.
LIFR TO VLIFR CONDITIONS ARE ONGOING AT KMLS AND KBHK. EXPECT
CONDITIONS TO BEGIN IMPROVING BY 16-17Z. MATOS
PRELIMINARY POINT TEMP/POPS
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 056 033/055 034/057 034/047 025/036 019/035 024/040
0/U 00/B 00/U 03/O 21/B 01/B 23/S
LVM 054 031/054 031/056 031/041 019/034 017/038 025/043
0/N 00/N 00/U 14/O 21/B 12/S 33/O
HDN 056 029/056 027/057 029/049 022/036 016/035 020/039
0/U 00/B 00/U 03/O 31/B 11/B 23/S
MLS 053 030/052 029/055 029/048 022/032 014/030 016/032
0/U 00/B 00/U 01/B 32/S 10/B 11/E
4BQ 055 032/054 029/055 031/048 022/032 015/032 019/036
0/U 00/U 00/U 01/B 32/S 10/B 11/E
BHK 053 027/051 027/056 029/048 019/030 010/030 011/031
0/B 00/B 00/U 01/B 33/S 10/B 11/B
SHR 056 027/055 027/058 027/048 017/034 012/035 018/040
0/U 00/U 00/U 03/O 41/N 10/B 12/S
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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