549
FXUS65 KBYZ 121103
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
503 AM MDT SUN OCT 12 2025
KEY MESSAGES
- WEATHER SYSTEM BRINGS SECONDARY PUSH OF MORE WIDESPREAD
PRECIPITATION, BLUSTERY WINDS, AND COOLER TEMPERATURES TO THE
REGION TODAY.
- FROST/FREEZE FOR MOST AREAS TONIGHT AND AGAIN MONDAY NIGHT.
- LIGHT SNOW ACCUMULATIONS MAY IMPACT US-191 NORTH OF BIG TIMBER
TO JUDITH GAP FOR MONDAY MORNING COMMUTE.
UPDATE
SEE UPDATED AVIATION DISCUSSION BELOW.
DISCUSSION
TODAY THROUGH MONDAY...
QUITE A BIT OF LIGHTNING, WIND AND HEAVY RAIN MADE ITS WAY ACROSS
PORTIONS OF OUR CWA LAST EVENING AND INTO THE EARLY HOURS OF THE
MORNING, MAINLY FROM THE PRYORS UP TO FORSYTH AND MILES CITY, AS
AN UNUSUALLY UNSTABLE ATMOSPHERE FOR THIS TIME OF YEAR DEVELOPED
AHEAD OF THE UPPER TROUGH MOVING INTO THE REGION FROM THE WEST. A
WIDESPREAD CLOUD SHIELD WITH COOLING TOPS WAS NOTED ON SATELLITE
IMAGERY OVER MUCH OF SOUTHERN MONTANA AT THIS TIME, INDICATIVE OF
THE WIDESPREAD MODERATE RAIN WE HAVE TRANSITIONED TO THANKS TO
STRONG UPPER DYNAMICS MOVING RIGHT ACROSS OUR AREA. OBSERVATIONS
INDICATE SNOW LEVELS HAVE DROPPED TO AT LEAST 7000FT IN THE
CRAZIES AND NEAR 8000 FT IN THE BEARTOOTHS. AS THE TROUGH MOVES
ACROSS OUR REGION THROUGH THE EARLY MORNING EXPECT WIDESPREAD
STRATIFORM PRECIPITATION, WITH POCKETS OF MODERATE TO HEAVY RAIN
AND MOUNTAIN SNOW...SPREADING TO THE FAR EASTERN SECTIONS NEAR THE
DAKOTAS BY MID MORNING, WITH DECREASING AREAL COVERAGE IN THE
WEST.
BY LATE MORNING TO MID-DAY SUNDAY, THE UPPER TROUGH AXIS WILL
HAVE LIFTED EAST/NORTHEAST TAKING MUCH OF THE HEAVIER
PRECIPITATION WITH IT. LOOK FOR A FEW LINGERING SHOWERS GENERALLY
WEST AND SOUTH OF BILLINGS, AND SOME AREAS OF SNOW SHOWERS OVER
THE HIGH COUNTRY. THE MAIN WEATHER FEATURE THOUGH WILL TURN TO
BLUSTERY WINDS ACROSS THE PLAINS BEHIND A SECONDARY PUSH OF
COLDER AIR BEHIND THE EXITING TROUGH. THE STRONG COLD AIR
ADVECTION WILL RESULT IN NORTHWESTERLY WINDS GUSTING 20 TO 35 MPH
FOR MOST LOCATIONS, WITH GUSTS IN THE 40S TO 50 MPH POSSIBLE IN
FAR EASTERN MONTANA NEAR THE DAKOTAS (MODERATE CHANCE OF 50 MPH OR
GREATER GUSTS IN FAR EASTERN MONTANA). HIGHS ON SUNDAY WILL BE
MUCH COOLER THAN TODAY WITH READINGS IN THE 40S AND 50S.
BY SUNDAY EVENING, A SURFACE HIGH STARTS TO SETTLE OVER THE HIGH
PLAINS BRINGING THE BRISK NW WINDS TO AN END AND CREATING A
SHALLOW EASTERLY LOW LEVEL FLOW. CROSS SECTIONS INDICATE A STRATUS
LAYER DEVELOPING FROM ABOUT YELLOWSTONE COUNTY WEST INTO THE
FOOTHILLS. BETWEEN THE WEAK USPLOPE AND A MOIST SW MID LEVEL
FLOW, THE MODELS PRODUCE LIGHT SNOW OVER THE CRAZIES AND NEARBY
FOOTHILLS LATE TONIGHT INTO MONDAY. A COUPLE OF INCHES OF
ACCUMULATION IS POSSIBLE IN THE MELVILLE FOOTHILLS, AND MAYBE
AROUND AN INCH AROUND HARLOWTON TO JUDITH GAP. THUS, TRAVEL ON
US-191 FROM BIG TIMBER TO JUDITH GAP MAY INCUR MINOR IMPACTS FOR
THE MONDAY MORNING COMMUTE. ANY SNOW SHOULD ALL BUT END BY MID DAY
MONDAY. HIGHS ON MONDAY WILL BE STUCK IN THE UPPER 30S TO LOWER
40S OVER OUR WESTERN ZONES THANKS TO THAT STUBBORN STRATUS, WHILE
AREAS FURTHER EAST PUSH INTO THE LOWER 50S.
MANY LOCATIONS WILL HAVE A CHANCE OF SEEING A FROST/FREEZE
BY SUNRISE MONDAY, THOUGH THAT LOW STRATUS DECK MAY PREVENT SOME
AREAS FROM DROPPING QUITE THAT LOW (BILLINGS 50%, MILES CITY 70%,
AND BAKER, SHERIDAN, LIVINGSTON 95% CHANCE OF FREEZE). WESTERN
ZONES WILL HAVE A GOOD SHOT OF A FROST/FREEZE AGAIN MONDAY NIGHT
WHILE TEMPS OUT EAST ARE NOT QUITE AS COLD.
TUESDAY THROUGH SATURDAY...
COOL AND UNSETTLED WEATHER LOOKS TO CONTINUE TUESDAY INTO THE END
OF THE WEEK. ANOTHER LARGE LOW PRESSURE SYSTEM DROPS DOWN ALONG
THE WEST COAST EARLY IN THE WEEK, AND ENSEMBLES AGREE THIS SYSTEM
WILL THEN TRACK NORTHEAST THROUGH THE ROCKIES WITH THE WEIGHT OF
CLUSTER ANALYSIS SUGGESTING ITS MOVES RIGHT OVER EASTERN MT BY
WEDNESDAY NIGHT. ENSEMBLES THEN DIFFER ON HOW FAST THE SYSTEM
EXITS THROUGH THE HIGH PLAINS INTO CANADA. WHILE THE DETAILS
REMAIN UNCERTAIN THIS FAR OUT, PORTIONS OF OUR CWA COULD GET
ANOTHER HEALTHY DOSE OF PRECIPITATION, ALONG WITH ACCUMULATING
SNOWFALL AGAIN IN THE HIGH COUNTRY FOR THE LATTER HALF OF THE
WEEK. LOOK FOR HIGH TEMPERATURES TO GENERALLY REMAIN IN THE UPPER
40S TO LOWER 60S. IF YOU HAVE OUTDOOR OR TRAVEL PLANS, BE SURE TO
MONITOR THE FORECAST. BT
AVIATION
LOW ELEVATION RAIN SHOWERS AND MOUNTAIN SNOWFALL CONTINUE THIS
MORNING. GUSTY NW WINDS 30-40KTS WILL CONTINUE TO SPREAD ACROSS
THE AREA, AS A COLD FRONT MOVES THROUGH SOUTHEASTERN MT. LOCALLY
HIGHER GUSTS TO 45KTS ARE POSSIBLE IN EASTERN MT (KMLS, KBHK).
MVFR/IFR CONDITIONS WILL BE POSSIBLE THROUGH 12Z WITH CONDITIONS
GENERALLY IMPROVING THROUGH THE MORNING. MOUNTAIN OBSCURATIONS ARE
EXPECTED THROUGH THE PERIOD. FOG MAY DEVELOP AROUND KLVM, KSHR,
KMLS, AND KBHK TONIGHT. PM
PRELIMINARY POINT TEMP/POPS
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 054 031/043 032/051 039/053 040/054 039/058 037/053
4/R 21/E 11/B 35/W 66/W 42/W 43/W
LVM 053 026/039 026/050 032/050 032/050 030/053 028/051
6/R 52/S 22/W 67/W 77/W 43/W 53/W
HDN 054 029/049 032/055 036/056 038/055 036/060 034/054
7/R 10/B 11/B 35/W 77/W 43/W 43/W
MLS 052 029/051 038/060 042/062 039/055 038/058 036/053
6/R 00/U 11/B 34/W 66/W 42/W 22/W
4BQ 054 029/055 042/061 043/068 041/053 038/058 036/052
5/R 00/U 11/B 23/T 65/W 32/W 22/W
BHK 052 023/051 034/055 038/060 038/055 033/058 032/054
4/R 00/U 11/N 23/W 75/W 32/W 11/B
SHR 057 024/052 030/061 037/063 034/054 031/059 029/051
7/R 00/B 11/B 24/W 76/W 32/W 44/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page