303
FXUS65 KBYZ 212017
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
117 PM MST FRI NOV 21 2025
KEY MESSAGES
- DRY & WARM (10-15F ABOVE NORMAL) THROUGH THE WEEKEND.
- BREEZY WINDS FOR THE WESTERN FOOTHILLS THIS WEEKEND; A PERIOD OF
STRONGER WINDS EXPECTED SUNDAY NIGHT AND MONDAY.
- TURNING WINDY AND COLDER REGIONWIDE MONDAY AND MONDAY NIGHT,
WITH SCATTERED RAIN AND SNOW SHOWERS.
- PERIODS OF LIGHT SNOW POSSIBLE TUESDAY THROUGH THANKSGIVING DAY,
WITH TEMPS IN THE 30S TO MID 40S (WARMEST NEAR FOOTHILLS).
- DETAILS UNCERTAIN, BUT CONFIDENCE INCREASING FOR A SURGE OF
COLDER AIR AND ACCUMULATING SNOW FRIDAY THROUGH NEXT WEEKEND; BE
PREPARED FOR WINTRY IMPACTS TO HOLIDAY TRAVEL, AND MONITOR THE
FORECAST!
DISCUSSION
THROUGH NEXT FRIDAY...
DO YOU HAVE THANKSGIVING TRAVEL PLANS? BE PREPARED FOR WINTRY
CONDITIONS AND MONITOR THE FORECAST!
DRY ZONAL FLOW W/ ABOVE NORMAL HEIGHTS WILL KEEP US WARM & DRY
THROUGH THE WEEKEND. LOOK FOR HIGHS IN THE 50S TO NEAR 60F...A
GOOD 10-15F ABOVE NORMAL. WINDS ALONG THE WESTERN FOOTHILLS WILL
BE GENERALLY BREEZY BUT GUSTS SHOULD REMAIN UNDER 50 MPH. GUSTS
TODAY HAVE ACTUALLY OVERACHIEVED A BIT WITH 40-45 MPH GUSTS NOTED
IN WHEATLAND COUNTY, AND NEAR 40 MPH IN SWEET GRASS. THIS IS ALONG
AXIS OF STRONGEST MID LEVEL WINDS W/ A BIT MORE MIXING THAN MODELS
WERE SUGGESTING FOR TODAY.
A PERIOD OF STRONGER WINDS IS EXPECTED ALONG THE WESTERN FOOTHILLS
SUNDAY NIGHT INTO MONDAY, IN ADVANCE OF A STRONG FRONTAL PASSAGE.
PRE-FRONTAL WINDS WILL IMPACT THE GAP LOCATIONS WITH POTENTIAL FOR
50 MPH GUSTS (50% CHANCE). AS COLD ADVECTION COMMENCES THE GAP
FLOW WILL WEAKEN AND HIGHEST GUSTS WILL SHIFT TO THE US-191
CORRIDOR ON MONDAY, WITH ~50% CHANCE OF GUSTS REACHING 50 MPH.
POST-FRONTAL WESTERLY WINDS WILL PUSH ACROSS THE PLAINS ON MONDAY
WITH 30-40 MPH GUSTS EXPECTED TO BE FAIRLY WIDESPREAD.
MONDAY'S COLD FRONT WILL SIGNAL THE ARRIVAL OF A SIGNIFICANT
PATTERN SHIFT, AND THE START OF PLENTY OF MODEL UNCERTAINTY.
GENERALLY SPEAKING, LOOK FOR A TRANSITION TO COLDER TEMPS AND
WINDY CONDITIONS MONDAY INTO TUESDAY, WITH A FAIRLY SHORT PERIOD
OF SCATTERED RAIN/SNOW SHOWERS. GREATEST POTENTIAL FOR SNOW WILL
BE OVER THE MOUNTAINS (1-4" EXPECTED), THE SOUTHERN FOOTHILLS AND
HIGHER HILLS (1" OR LESS) AND THE FAR EAST (35-45% OF MEASURABLE
SNOW). OF MUCH LOWER CONFIDENCE IS WHAT WILL HAPPEN IN FAR
SOUTHEAST MT MONDAY NIGHT AND TUESDAY. THE GFS AND ITS ENSEMBLES
CONTINUE TO SHOW THE MID LEVEL LOW DEEPENING IN THE DAKOTAS AND
ALLOWING FOR SOME TROWAL SNOWFALL AND STRONG NW WINDS, ESPECIALLY
EAST OF ROSEBUD COUNTY. OTHER MODELS/ENSEMBLES SHOW THE WAVE
REMAINING OPEN AND TRANSITORY, BRINGING MODESTLY BREEZY CONDITIONS
AND MUCH LESS PRECIP POTENTIAL FOR OUR EAST. MODEL TRENDS WILL
NEED TO BE MONITORED HERE AS IF THE GEFS (THE OUTLIER) VERIFIES
WE'D BE LOOKING AT A PERIOD OF SNOW AND BLOWING SNOW WITH SUB-
FREEZING TEMPS IN OUR EAST. GEFS SHOWS A MEAN SNOWFALL OF 2" AND
>40MPH GUSTS AT BAKER ON TUESDAY, FOR EXAMPLE.
WEDNESDAY AND THURSDAY "SHOULD" BE QUIETER WITH RISING HEIGHTS
ASSOCIATED WITH FLAT RIDGING BEHIND THE MON/TUE WAVE (WHATEVER IT
DOES). WE SHOULD REMAIN ON THE COLD SIDE OF THE SURFACE BOUNDARY
WEDNESDAY, BUT THERE MAY BE LEE SIDE TROFFING WEDNESDAY NIGHT AND
THURSDAY...AND IF THIS WERE TO HAPPEN IT WOULD OPEN THE DOOR TO
WARMER TEMPS AND GUSTY GAP WINDS ALONG THE FOOTHILLS. PLENTY OF
UNCERTAINTY HERE, BUT NOTE THE WARMER FORECAST FOR THANKSGIVING
DAY TO ACCOMMODATE THIS TREND, WHICH HAS THE ENSEMBLE CONSENSUS.
IT IS LOOKING MORE AND MORE LIKELY THAT ANY SIGNIFICANT IMPACTS
FROM WINTRY WEATHER WILL BE IN THE DAYS AFTER THANKSGIVING. THERE
IS HIGH CONFIDENCE FOR A SURGE OF COLDER AIR STARTING FRIDAY AND
CONTINUING THROUGH THE WEEKEND, ALONG WITH DEEP TROFFING THAT
SUPPORTS SOME ACCUMULATING SNOW ACROSS LOWER ELEVATIONS. DETAILS
ARE IMPOSSIBLE AT THIS TIME, BUT THIS WILL EASILY BE THE COLDEST
AIR YET OF THE FALL. TO GIVE AN IDEA OF THE MODEL UNCERTAINTY, THE
10-90TH PERCENTILE MAX TEMPS ON FRIDAY AT BILLINGS ARE 26F AND
52F. STAY TUNED!
THE BOTTOM LINE IS, IF YOU HAVE TRAVEL PLANS OVER THE HOLIDAY
WEEKEND PLEASE MONITOR THE FORECAST FOR CHANGES AND GREATER
DETAIL.
JKL
AVIATION
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. BREEZY CONDITIONS
ARE FORECAST IN THE FOOTHILLS WEST OF BILLINGS OVERNIGHT, WITH
GUSTS UP TO 35 KNOTS. MATOS
PRELIMINARY POINT TEMP/POPS
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 033/055 035/057 036/047 024/038 021/038 026/040 025/038
00/B 00/U 03/W 10/B 01/E 33/J 23/S
LVM 031/055 031/057 031/042 018/035 019/039 029/045 029/042
00/B 00/N 14/W 11/B 13/J 43/W 23/O
HDN 029/055 027/057 031/048 022/039 016/037 023/039 021/039
00/B 00/U 04/W 21/B 01/B 33/W 23/S
MLS 030/051 030/057 031/048 021/032 015/032 018/032 018/032
00/U 00/U 02/W 31/B 00/B 22/J 22/S
4BQ 031/053 030/056 031/048 023/034 017/034 021/036 021/036
00/U 00/U 02/W 21/B 00/B 12/J 11/E
BHK 027/051 029/056 029/047 018/031 012/032 012/032 013/031
00/B 00/U 02/W 32/J 10/B 12/J 11/E
SHR 027/054 028/058 027/048 016/035 014/037 019/041 021/042
00/U 00/U 03/W 31/B 00/B 23/W 22/O
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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