215
FXUS65 KBYZ 091328
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
628 AM MST MON FEB 9 2026
KEY MESSAGES
- COOLER WITH GOOD CHANCES FOR PRECIPITATION TODAY (50-90%).
- ACCUMULATING SNOW (1 TO 6 INCHES) FOR AREAS ALONG AND NORTH OF
I-90 FROM HARDIN TO LIVINGSTON TODAY, HEAVIEST ALONG THE
MUSSELSHELL RIVER VALLEY. 1 TO 2 FEET OF SNOW FORECAST FOR THE
WESTERN MOUNTAINS.
- A COOLER AND QUIET WEATHER PATTERN FOR THE REST OF THE WORK
WEEK. TEMPERATURES WILL BE MUCH CLOSER TO AVERAGE COMPARED TO
THE PAST FEW WEEKS.
UPDATE
UPDATED FORECAST FOR THE LATEST MODEL AND RADAR TRENDS THROUGH
TONIGHT. CURRENTLY THE JET STREAM CROSSING THE BEARTOOTH
MOUNTAINS FROM SW- NE IS DOWNSLOPING AREAS FROM THE BEARTOOTH
FRONT NORTHEAST INTO BILLINGS. UPDATED THE FORECAST FOR THIS. AS
THE JET SAGS SOUTH IT WILL SHIFT THIS PRECIPITATION SHADOW SOUTH
AS WELL AND ALLOW PRECIPITATION, MAINLY SNOW NOW, TO SPREAD SOUTH
AND EASTWARD, SO STILL EXPECTING HIGH PRECIPITATION CHANCES AND AT
LEAST A FEW TENTHS OF PRECIPITATION OVER AREAS FROM BILLINGS EAST
ALONG I-90 AND I-94 THIS MORNING. SNOW ACCUMULATION FORECAST NOW
REFLECTS AMOUNTS FROM NOW THROUGH THIS EVENING. NO CHANGES TO
CURRENT WINTER WEATHER ADVISORIES. CHAMBERS
DISCUSSION
THIS MORNING THROUGH SUNDAY...
HIGHLITES: WITH THE ARRIVAL OF THE COLD FRONT AND WIDESPREAD LIFT
WINDS ARE DIMINISHING OVER THE WESTERN FOOTHILLS AND THEREFORE
CANCELLED THE WIND ADVISORY. COULD STILL SEE A FEW GUSTS AROUND 50
MPH FOR A FEW MORE HOURS RIGHT AROUND THE YELLOWSTONE EXIT ON
I-90 AT LIVINGSTON SO CONTINUE TO USE CAUTION ON I-90 IN THAT
AREA. ADDED NORTHERN SWEET GRASS AND NORTHERN STILLWATER COUNTIES
TO THE GOING WINTER WEATHER ADVISORY. AREAS WELL NORTH OF THE I-90
CORRIDOR ARE THE FOCUS FOR THIS ADVISORY EXTENSION AS THE HIGHER
HILLS FROM MELVILLE EAST TO RAPELJE AND MAYBE AS FAR EAST AS MOLT
WILL SEE SNOW TOTALS IN THE 3 TO 6 INCH RANGE BY LATE MONDAY
MORNING.
SYNOPSIS: COMPLICATED WEATHER PATTERN OVER THE AREA WITH THE
MODELS REALLY SHIFTING TOWARD A MORE IMPACTFUL WINTER SYSTEM OVER
THE PAST 6 TO 12 HOURS. SATELLITE SHOWS AN IMPRESSIVE DOUBLE
BAROCLINIC LEAF PATTERN OVER SW MONTANA AND IDAHO WITH SIGNIFICANT
PACIFIC MOISTURE BEING ENTRAINED INTO THE SYSTEM. JET ANALYSIS
SHOWS AN EXITING 60 TO 80KT JET PUSHING EAST INTO THE DAKOTAS
WHILE THE PACIFIC JET NOSES IN FROM THE SOUTHWEST AT 120-140KTS.
THE INTERACTION BETWEEN THE APPROACHING JET AND THE EXITING JET IS
FORECAS TO GENERATE SIGNIFICANT DIVERGENCE OVER THE WESTERN HALF
OF THE FORECAST AREA PROVIDING THE LIFT FOR THE INCREASED
PRECIPITATION BEING FORECAST OVER THE PAST 12 HOURS. BY THIS
AFTERNOON THE WHOLE SYSTEM WILL SHIFT SOUTH OF THE AREA WITH
UNSTABLE NORTHWESTERLY WINDS FILLING IN ACROSS THE AREA. AT THIS
POINT PRECIPITATION WILL REALLY DIMINISH AS DOWNSLOPE INFLUENCES
KICK IN, THOUGH SNOW BANDS OFF THE WESTERN MOUNTAINS DO LOOK TO
SPREAD WELL SOUTHEAST INTO THE PLAINS AND MAY IMPACT BILLINGS INTO
THE LATE AFTERNOON.
A SPLIT FLOW PATTERN DEVELOPS FOR TUESDAY THROUGH THE REST OF THE
WEEK. THIS KEEPS THE NORTHERN ROCKIES IN A CALMER AREA BETWEEN AN
UPPER LOW OVER THE GREAT BASIN TO THE SOUTH AND A STRONGER JET
HOLDING COLD CANADIAN AIR TO THE NORTH. IN SHORT THIS PATTERN IS A
PRETTY BENIGN ONE FOR OUR AREA. EXPECT TEMPERATURES TO BE MAINLY
IN THE 40S TO LOWER 50S THROUGH THE WEEK. WHILE NOT COMPLETELY
DRY, UPPER LOW MAY GET CLOSE ENOUGH WEDNESDAY FOR SCATTERED
SHOWERS ALONG OUR SOUTHERN TIER, THERE ISN'T ANY SIGNIFICANT
PRECIPITATION FORECAST OUTSIDE OF THE WESTERN MOUNTAINS
(WEST/SOUTH FACING SLOPES). BY SATURDAY THE PACIFIC JET BUILDS
BACK OVER OUR AREA FOR STRONGER DOWNSLOPE FLOW. THIS WILL BOOST
TEMPERATURES WELL INTO THE MID TO UPPER 50S, MAYBE LOWER 60S FOR
THE WEEKEND. WESTERN FOOTHILLS WILL SEE WINDS INCREASE AND BECOME
GUSTY TO LOCALLY STRONG AT TIMES.
PRECIPITATION AND SNOWFALL TODAY: GIVEN THE STRONGER FORCING ALOFT
MODELS PUSHED FORECAST PRECIPITATION AMOUNTS UP A TWO TO THREE
TENTHS OF AN INCH WITH THE LATEST RUNS ACROSS MUCH OF SC MONTANA,
AND MANY GFS/ECMWF ENSEMBLE MEMBERS WENT HIGHER THAN THAT. WHILE
NOT AS IMPRESSIVE, SE MONTANA ALSO SAW INCREASES AROUND A TENTH OF
AN INCH. GIVEN THE STRENGTH OF THE UPPER DYNAMICS, THE IMPRESSIVE
MOISTURE FETCH SHOWN ON SATELLITE, AND THE OVER-RUNNING/UP-SLOPING
NORTHERLY FLOW BEHIND THE FRONT WORKING THROUGH THE AREA THIS
INCREASE SEEMS REASONABLE. THAT SAID MODELS SOMETIMES GET A BIT
CARRIED AWAY WITH PRECIPITATION TOTALS OVER WHEATLAND COUNTY AND
NEARBY LOCATIONS, SO CAPPING THAT AREA AT HALF AN INCH OR SO
COMPARED TO AROUND AN INCH IN SOME MODEL SOLUTIONS.
SO, THE PRECIPITATION INCREASE SEEMS REASONABLE. WHAT ABOUT THE
SNOWFALL? ECMWF/GFS ENSEMBLES HAVE GONE BONKERS WITH SNOWFALL
AMOUNTS SHOWING WELL OVER A FOOT FOR AREAS FROM HARLOWTON EAST
ALONG THE MUSSELSHELL RIVER AND 4 TO 8 INCHES DOWN TO THE I-90
CORRIDOR. THE HRRR WHICH CAN GO WAY HIGH WITH SNOWFALL AMOUNTS IN
CERTAIN SCENARIOS IS DOING SO WITH THIS ONE, SHOWING SIMILAR
AMOUNTS. THE DRIVING FACTOR LOOKS TO BE DENDRITIC GROWTH AT 700MB
AND AGAIN NEAR THE SURFACE COMBINED WITH THE STRONG FORCING
PROVIDED BY THE JET MOVING OVERHEAD. DYNAMIC COOLING DOES HAVE A
STRONG INFLUENCE ON SNOWFALL IN THIS AREA, BUT LOOKING AT
SOUNDINGS AND GIVEN THE WARM SURFACE TEMPERATURES THE MODELS SEEM
TO BE WAY OVERDOING THE SNOWFALL WITH THIS SYSTEM. THE NBM IS
LAGGING WAY BEHIND THE DETERMINISTIC AND LATEST ENSEMBLES SO USING
PROBABILITIES TONIGHT IS NOT A GOOD IDEA OUTSIDE OF THE FACT THAT
ITS NOT BEING INFLUENCED AS MUCH BY THE LATEST RUNS GOING SO HIGH
WITH SNOWFALL AMOUNTS. IN COLLABORATION WITH WPC HAVE INCREASED
PRECIPITATION AND SNOW ACCUMULATIONS SIGNIFICANTLY ABOVE NBM
LEVELS, BUT NOT GOING AS HIGH AS THE LATEST GFS/ECMWF ENSEMBLES.
THIS GIVES 2 TO 6 INCHES OF SNOW ALONG THE MUSSELSHELL RIVER
VALLEY TRENDING DOWN TO AROUND AN INCH ALONG THE I-90 CORRIDOR
FROM LIVINGSTON TO BILLINGS. GIVEN THE WARM GROUND TEMPERATURES
(AND AIR TEMPERATURES FOR THAT MATTER) EXPECT GRASSY AREAS TO
ACCUMULATE MORE SNOW THAN ROADWAYS. THE TRANSITION FROM RAIN TO
SNOW WILL COME DURING THE MORNING COMMUTE ALONG THE I-90 CORRIDOR
INCLUDING BILLINGS.
WESTERN MOUNTAINS ARE LOOKING AT A FOOT IN THE LOWER REACHES
AROUND 6000 FEET, TO 2 FEET IN THE HIGHER WEST FACING TERRAIN
ABOVE 8000 FEET. STRONG WINDS IN THE MOUNTAINS WILL PRODUCE
DANGEROUS BLOWING AND DRIFTING SNOW AND INCREASED AVALANCHE
DANGER. THOSE PLANNING MOUNTAIN RECREATION SHOULD BE PREPARED FOR
DANGEROUS WINTER CONDITIONS, OR POSTPONE ACTIVITIES UNTIL THIS
SYSTEM PASSES. THE BIGHORN MOUNTAINS ARE EXPECTED TO MISS OUT ON
THE BRUNT OF THE MOISTURE/SNOW WITH THIS SYSTEM, BUT WILL SEE
STRONGER WINDS OF 40 TO 60 MPH AT TIMES THROUGH MID DAY MONDAY.
NORMALLY WE START TO SEE SNOW DEVELOP AS SURFACE TEMPERATURES
REACH 36 DEGREES AND THAT SEEMS TO BE THE CASE TONIGHT. SNOW IS
FALLING IN JUDITH GAP BUT ELSEWHERE TEMPERATURES ARE STILL WARM
ENOUGH FOR RAIN. EXPECT THAT TO CHANGE OVER THE NEXT FEW HOURS
WITH SNOW DEVELOPING OVER NORTHERN TIER ZONES AND SPREADING SLOWLY
SOUTHWARD INTO THE SUNRISE HOURS THIS MORNING. HAVE ALREADY PICKED
UP 0.2 TO 0.3 PRECIPITATION ALONG THE MUSSELSHELL RIVER VALLEY
SINCE 6PM LAST EVENING.
ONE FINAL THING TO MENTION, IS THE DOWNSLOPE WINDS ALONG THE
NORTH/EAST SLOPES OF THE BEARTOOTH AND BIGHORN MOUNTAINS. THE
ORIENTATION AND POSITION OF THE JET STREAM ARE LINED UP TO BRING
THE POTENTIAL FOR MOUNTAIN WAVE WIND GUSTS TO THESE FOOTHILLS THIS
MORNING. THE HRRR 80M WINDS SUPPORT THIS POTENTIAL WITH STRONG
GUSTS IN THE HIGHER TERRAIN TRYING TO MOVE DOWN THE HILL INTO
POPULATED AREAS (RED LODGE, SHERIDAN). BUMPED WIND GUSTS UP TO
30-40MPH THIS MORNING TO ACCOUNT FOR THIS AND WILL BE KEEPING A
CLOSE EYE ON WINDS UNTIL THE JET DIPS SOUTH OF THE AREA. THESE
DOWNSLOPE ORIENTED WINDS WILL ALSO WORK TO LIMIT PRECIPITATION IN
THESE AREAS TO MUCH LESS THAN AREAS FURTHER NORTH.
IN SUMMARY, A COOLER AND UNSETTLED DAY TODAY WITH THE POTENTIAL
FOR IMPACTFUL SNOWFALL NORTH AND WEST OF BILLINGS AND INTO THE
MOUNTAINS. ONCE THIS SYSTEM EXITS TONIGHT, THE WEATHER PATTERN FOR
THE REST OF THE WORK WEEK BECOMES QUIET WITH TEMPERATURES THROUGH
THE WEEK MUCH CLOSER TO SEASONAL THAN THEY HAVE BEEN, AND NOT
MUCH IN THE WAY OF PRECIPITATION OUTSIDE OF THE MOUNTAINS.
CHAMBERS
AVIATION
PRECIPITATION IS STARTING TO FILL INTO THE AREA. EXPECT THIS TO
INITIALLY FALL AS RAIN BEFORE A QUICK TRANSITION TO SNOW. IFR
CONDITIONS ARE FORECAST AT ALL SITES DURING THE HEAVIEST PERIOD OF
SNOW. FOR KBIL THIS WILL BE BETWEEN 12-20Z WHERE SOME LIFR
CONDITIONS ARE POSSIBLE WITH HEAVIER BURSTS OF SNOW AND LOCALIZED
FOG AND LOWERING CEILINGS. WINDS MY BE GUSTY (UP TO 30KTS) ACROSS
THE FORECAST AREA WITH A MOSTLY NORTHERLY COMPONENT. LOCATIONS
NEAR K3HT/KRPX MAY SEE ACCUMULATING SNOW AND VLIFR CONDITIONS AT
TIMES THROUGH 18Z. MOUNTAINS WILL REMAIN OBSCURED. VFR CONDITIONS
RETURN TO ALL SITES AFTER 00Z. WMR
PRELIMINARY POINT TEMP/POPS
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 039 025/046 025/046 025/049 026/050 027/051 029/052
8/O 30/B 02/O 10/U 00/U 01/B 12/O
LVM 040 023/043 024/045 025/045 025/046 026/046 029/046
8/O 30/B 03/O 21/U 00/U 11/B 24/S
HDN 040 024/048 023/047 024/050 023/052 025/053 027/055
9/O 30/B 01/E 21/U 00/U 01/B 12/O
MLS 039 026/045 023/045 023/046 023/048 024/049 026/050
9/O 10/B 00/E 00/U 00/U 00/B 01/B
4BQ 040 026/046 026/049 026/048 026/052 026/051 027/054
6/O 20/U 01/E 11/U 00/U 00/B 01/B
BHK 036 023/043 022/046 022/045 023/047 022/047 024/047
7/O 10/B 00/E 10/U 00/U 00/B 01/B
SHR 041 020/045 020/048 023/047 022/049 022/050 023/052
6/O 41/B 12/O 32/O 01/U 11/B 12/O
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON FOR ZONES 29-34-42-63-141-172-228.
WINTER STORM WARNING IN EFFECT UNTIL 5 PM MST THIS AFTERNOON
FOR ZONES 67-68.
WY...NONE.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page