146
FXUS65 KBYZ 232017
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
117 PM MST TUE DEC 23 2025
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES EXPECTED THROUGH FRIDAY.
- WEAK COLD FRONT MAY (20-40%) BRING A SHOT OF RAIN/SNOW WEST OF
ROSEBUD COUNTY CHRISTMAS DAY, BUT NO BIG STORMS EXPECTED.
- COOLER AND CHANCE (20-50%) FOR LIGHT RAIN/SNOW FRIDAY NIGHT INTO
SATURDAY. CHANCES FOR STRONG WINDS AND POTENTIAL TRAVEL HAZARDS
ARE INCREASING.
- PERSISTENT LIGHT TO MODERATE SNOW FOR THE BEARTOOTH/ABSAROKA
MOUNTAINS THURSDAY THROUGH SATURDAY. 50% CHANCE FOR GREATER THAN
12 INCHES OVER THE HIGHEST PEAKS.
DISCUSSION
THROUGH TUESDAY...
MUCH ABOVE AVERAGE TEMPERATURES AND DRY CONDITIONS ARE EXPECTED
WEDNESDAY WITH HIGH TEMPERATURES IN THE 40S AND 50S F. CHRISTMAS
DAY WILL SEE A WEAK COLD FRONT MOVE THROUGH THE REGION BRINGING
LOW CHANCES (20-30%) FOR PRECIPITATION FOR THE LOWER ELEVATIONS.
IMPACTFUL PRECIPITATION ON CHRISTMAS DAY IS NOT EXPECTED WITH THE
BEARTOOTH/ABSAROKA FOOTHILLS HAVING A 20-40% CHANCE OF GETTING
GREATER THAN 0.1 INCHES OF RAIN. LOWER ELEVATIONS HAVE A LESS THAN
10% CHANCE. CHRISTMAS DAY AND FRIDAY WILL SEE MUCH ABOVE AVERAGE
TEMPERATURES CONTINUE WITH 40S AND 50S F EXPECTED.
UPPER LEVEL TROUGHING MOVES IN FOR THE WEEKEND BRINGING A COLD
FRONT THROUGH THE REGION EARLY SATURDAY. THIS WILL DECREASE HIGH
TEMPERATURES BY 10-20 DEGREES FOR THE DAY SATURDAY WITH HIGHS IN
THE 20S AND 30S F. TEMPERATURES RISE AROUND 5 DEGREES IN THE WEST
SUNDAY INTO THE 40S F WITH MORE STEADY TEMPERATURES IN THE EAST.
PATTERN RECOGNITION WOULD INDICATE STRONG WIND POTENTIAL FOR THE
PLAINS SATURDAY WITH THE COLD FRONTAL PASSAGE. IT APPEARS MODELS
ARE STARTING TO PICK UP ON THIS WITH THE ECMWF EFI TABLES STARTING
TO SHOW SOME CLIMATOLOGICALLY SIGNIFICANT VALUES. THIS COLD FRONT
WILL BRING A 20-40% CHANCE FOR RAIN AND SNOW TO MUCH OF THE
REGION. SIGNIFICANT PRECIPITATION IS NOT EXPECTED WITH THE NBM
INDICATING A 10-20% CHANCE FOR GREATER THAN 0.1 INCHES. HOWEVER,
TEMPERATURES WILL BE COLD ENOUGH TO MIX IN SOME SNOW SATURDAY.
STRONG WINDS AND A RAIN/SNOW MIX COULD IMPACT POST CHRISTMAS
TRAVEL AND IS WORTH MONITORING GOING FORWARD.
STARTING THURSDAY AND LASTING THROUGH SATURDAY, UPPER LEVEL
TROUGHING TO OUR WEST WILL PUT THE BEARTOOTH/ABSAROKA MOUNTAINS IN
FAVORABLE SOUTHWEST FLOW. THIS WILL LEAD TO A PROLONGED PERIOD OF
LIGHT TO MODERATE SNOW. THE NBM IS GIVING A 50% CHANCE FOR GREATER
THAN 12 INCHES OF SNOW OVER THE 72 HOUR PERIOD THURSDAY THROUGH
SATURDAY OVER THE HIGHEST PEAKS.
UPPER LEVEL RIDGING AND ABOVE AVERAGE TEMPERATURES RETURN EARLY
NEXT WORKWEEK INCREASING HIGH TEMPERATURES BACK INTO THE 40S AND
50S F. TORGERSON
AVIATION
PATCHES OF DENSE FOG CONTINUE TO AFFECT SOUTHEAST MT AS OF 20Z,
MOST NOTABLY AT K00U, ALONG THE YELLOWSTONE RIVER EAST OF KBIL,
AND IN PORTIONS OF CARTER COUNTY. THIS FOG MAY ERODE A BIT BEFORE
SUNSET, BUT OVERALL CONFIDENCE IS INCREASING FOR MORE MAINLY
VALLEY FOG FROM KBIL EASTWARD TONIGHT (30% CHANCE). BY 10-12Z, A
CANADIAN COLD FRONT SAGGING THRU EASTERN MT WILL SHIFT WINDS TO
THE NE-E AND MAY ASSIST IN FOG/STRATUS DEVELOPMENT NEAR KMLS &
KBHK BEFORE DAYBREAK WEDNESDAY. LOWER CONFIDENCE FOR FOG EXISTS AT
KBIL, AS THE ONSET OF SW WINDS MAY KEEP THE FOG RISK EAST OF THE
AIRPORT. THIS IS SOMETHING TO MONITOR. EXPECT REDUCTIONS TO LIFR-
VLIFR WHERE FOG DEVELOPS. ON WEDNESDAY, AREAS OF FOG/STRATUS COULD
LINGER FOR MUCH OF THE DAY IN THE EAST (I.E. EAST OF MUSSELSHELL-
YELLOWSTONE-BIG HORN COUNTIES) AS SURFACE WINDS TURN EASTERLY,
BUT THIS IS MUCH MORE UNCERTAIN.
OTHERWISE, LOOK FOR BREEZY SW-W WINDS ALONG THE WESTERN FOOTHILLS
TONIGHT INTO EARLY WEDNESDAY, W/ GUSTS OF 25-35 KNOTS AT KLVM.
JKL
PRELIMINARY POINT TEMP/POPS
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 033/053 035/054 035/055 025/035 013/035 022/047 031/053
00/B 12/R 01/B 13/S 00/B 00/B 01/B
LVM 038/054 040/054 036/049 026/035 018/039 024/046 031/051
00/U 55/R 24/O 33/S 00/B 00/B 01/B
HDN 029/051 030/050 031/055 021/035 008/032 016/044 026/050
00/B 11/B 01/B 24/S 00/B 00/B 01/B
MLS 026/040 027/042 027/050 016/030 003/022 011/037 025/046
00/B 01/E 00/B 22/S 00/B 00/B 01/B
4BQ 032/051 036/054 032/055 024/037 008/027 015/042 028/048
00/B 00/B 00/U 12/S 00/B 00/B 01/B
BHK 025/041 025/044 026/049 016/026 902/019 006/037 020/042
00/B 00/E 00/B 22/S 00/B 00/B 11/B
SHR 031/055 032/055 030/054 022/035 008/034 015/047 026/052
00/B 02/R 01/B 14/S 10/B 00/B 01/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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