376
FXUS65 KBYZ 140228
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
828 PM MDT MON OCT 13 2025
KEY MESSAGES
- AREAS OF LOW CLOUDS, FOG, VERY LIGHT SNOW AND DRIZZLE CONTINUE
IN THE WEST TONIGHT INTO TUESDAY; MORE FOG AND LOW CLOUDS
EXPECTED TUESDAY NIGHT INTO WEDNESDAY.
- INCREASING CHANCE OF PRECIPITATION TUESDAY NIGHT THROUGH
THURSDAY EVENING. HIGH ELEVATION SNOW ACCUMULATIONS POSSIBLE
(ABOVE 6500FT).
- BREEZY WITH SCATTERED SHOWERS FRIDAY.
- TURNING MAINLY DRY AND WARMER NEXT WEEKEND.
UPDATE
UPDATED FORECAST FOR LATEST MODEL TRENDS REGARDING MAINLY FOG AND
DRIZZLE OVERNIGHT, THEN LIGHT WARM ADVECTION PRECIPITATION CHANCES
FOR TOMORROW MORNING AROUND SUNRISE, FOR AREAS MAINLY WEST OF A
HYSHAM TO HARDIN TO SHERIDAN LINE. STILL LOOKING LIKE GOOD (20 TO
60%) CHANCES FOR FOG OVER THIS AREA WITH THE STRONGER POTENTIAL
THE CLOSER TO THE FOOTHILLS YOU GET. MODEL SOUNDINGS SUGGESTIVE OF
DRIZZLE/FREEZING DRIZZLE ACCOMPANYING THE LOW CLOUDS AND FOG AND
MADE THIS A BIT MORE PROMINENT OVERNIGHT. THERE ARE SOME RIPPLES
ALOFT PRODUCING SOME DEEPER CLOUD COVER THAT COULD PRODUCE SOME
INTERMITTENT LIGHT SNOW AS WELL BUT OVERALL DRIZZLE/FREEZING
DRIZZLE SHOULD BE THE MAIN PRECIPITATION TYPE OVERNIGHT AND IT
SHOULD BE LIGHT ENOUGH AND PATCHY ENOUGH TO NOT WARRANT ANY
HIGHLITES, BUT WILL KEEP A CLOSE EYE ON OBSERVATIONS OVERNIGHT.
NOT ANTICIPATING FOG HIGHLITES EITHER AT THIS POINT AS WINDS WILL
BE STRONG ENOUGH TO LIMIT WIDESPREAD DENSE FOG, THOUGH LOCALLY
VISIBILITY MAY DROP TO UNDER HALF A MILE AT TIMES ESPECIALLY IN
THE FOOTHILLS. ALREADY HAD A REPORT EARLIER THIS EVENING FROM THE
BIGHORN FOOTHILLS WEST OF DAYTON OF NEAR ZERO VISIBILITY AND
FREEZING DRIZZLE.
WARM ADVECTION KICKS IN JUST BEFORE SUNRISE AND PRODUCES AN AREA
OF BETTER LIFT OVER SOUTHERN ZONES, SPREADING NORTHWARD THROUGH
THE MORNING. THIS FEATURE SHOULD END DRIZZLE/FREEZING DRIZZLE AND
SHIFT OVER TO LIGHT SNOW/FLURRIES AND MAYBE SHIFTING TO VERY LIGHT
RAIN BEFORE ENDING LATE MORNING. FOG WILL LIFT THROUGH THIS
MORNING PERIOD AS WELL. OVERALL STILL LOOKING AT A HUNDREDTH OR
TWO AT MOST FOR PRECIPITATION THROUGH TOMORROW MORNING.
THOSE WITH TRAVEL PLANS FROM BILLINGS WEST SHOULD ANTICIPATE SOME
LOCALLY SLICK TRAVEL CONDITIONS WHEN FOG IS ENCOUNTERED,
ESPECIALLY ON BRIDGES AND OVERPASSES.
EAST OF THE FOG/STRATUS/DRIZZLE LINE, GUSTIER EAST/SOUTHEAST
WINDS ARE ADVECTING IN SLIGHTLY WARMER AND DRIER AIR WHICH WILL
KEEP MID/HIGH LEVEL CLOUD COVER AROUND BUT DRY CONDITIONS ALONG
WITH VERY LOW CHANCES FOR ANY LOW LYING FOG. CHAMBERS
DISCUSSION
TODAY THROUGH TUESDAY NIGHT...
SATELLITE IMAGERY SHOWS A DEEP TROF CONTINUING TO DIG ALONG THE
PACIFIC COAST, WITH SW FLOW EXTENDING FROM SOUTHERN CA TO MT.
DESPITE THE MID LEVEL WARMING, LOW LEVELS REMAIN CHILLY WITH
WIDESPREAD LOW STRATUS COURTESY OF EASTERLY UPSLOPE WINDS. THERE
ARE SOME CLEAR SKIES IN OUR EAST BUT THE CENTRAL AND WEST ARE
SOCKED IN. UP TO ABOUT 8000 FEET THAT IS. AS OF NOON, IT IS 21F AT
COLE CREEK SNOTEL AT 7900', AND 35F AT NEARBY QUAD CREEK RAWS AT
9700'. THERE CONTINUES TO BE INTERMITTENT LIGHT SNOW/FREEZING
DRIZZLE IN WHEATLAND COUNTY WHERE TEMPS REMAIN IN THE UPPER 20S.
PERSISTENT UPSLOPE WINDS AND A SATURATED BOUNDARY LAYER WILL KEEP
THE RISK OF LIGHT SNOW AND FZDZ GOING ALONG THE WESTERN FOOTHILLS
TONIGHT. IN FACT, AFTER SOME MODEST EROSION OF THE LOW CLOUDS WITH
LIMITED MIXING THIS AFTERNOON, EXPECT EXPANDING AREAS OF FOG/
STRATUS WEST OF ROSEBUD COUNTY AGAIN TONIGHT INTO TUESDAY. FULLY
EXPECT MORE FOG AND STRATUS TUESDAY NIGHT INTO WEDNESDAY, THOUGH
PROBABLY WITH LESS COVERAGE, AND W/O THE RISK OF DRIZZLE.
SOMETHING TO MONITOR.
A WEAK SHORTWAVE LIFTING THRU THE SW FLOW ALOFT WILL BRING A SHORT
PERIOD OF SCATTERED SHOWERS LATE TONIGHT AND TUESDAY MORNING. ONE
THING TO WATCH IS IF SUB-FREEZING SURFACE TEMPS IN OUR WEST
COINCIDE WITH THE PRECIP, WHICH SHOULD BE RAIN ACROSS MOST LOWER
ELEVATIONS. EAST HALF WILL BE WARMER AND NOT HAVE THIS RISK.
HEIGHT FALLS AND INCREASINGLY DIFFLUENT UPPER LEVEL WINDS WILL
RESULT IN INCREASING CHANCES OF PRECIP TUESDAY NIGHT. THERE MAY
EVEN BE ENOUGH ELEVATED INSTABILITY FOR A FEW WEAK THUNDERSTORMS.
TEMPS IN THE SHORT TERM WILL CONTINUE TO BE WARMEST IN THE EAST
AND COOLEST ALONG THE WESTERN FOOTHILLS. LOOK FOR HIGHS IN THE MID
40S TO MID 60S TUESDAY.
JKL
WEDNESDAY THROUGH MONDAY...
MODELS CONTINUE TO AGREE ON ANOTHER SYSTEM IMPACTING THE REGION
WEDNESDAY INTO THURSDAY. THERE IS STILL DISAGREEMENT ON HOW MUCH
PRECIPITATION IS POSSIBLE, WITH LOWER END AMOUNTS AROUND 0.2-0.5
INCHES AND HIGH END AMOUNTS AROUND 0.75-1.25 INCHES. OVERALL,
MODELS HAVE TRENDED TOWARDS THE HIGHER END COMPARED TO PREVIOUS
RUNS, WITH A 40-60% CHANCE OF AT LEAST 0.5" OVER THE PLAINS AND A
60-80% CHANCE OF THE SAME OVER THE MOUNTAINS.
SNOW LEVELS WILL FALL WEDNESDAY INTO THURSDAY TO AROUND 7,000 FT.
A FEW FLAKES MAY FALL AT LOWER ELEVATIONS, BUT TEMPERATURES WILL
BE AROUND 10 DEGREES WARMER WEDNESDAY AND THURSDAY COMPARED TO
TODAY, SO IT IS HIGHLY UNLIKELY (<10% CHANCE) AT THIS TIME.
CURRENTLY, THERE IS 70% CHANCE OF AT LEAST 6 INCHES OF SNOW OVER
THE HIGHEST PEAKS OF THE ABSAROKA/BEARTOOTH MOUNTAINS AND A 40%
CHANCE OF THE SAME OVER THE BIGHORN MOUNTAINS.
AFTER THE SYSTEM EXITS LATE THURSDAY/EARLY FRIDAY, ANOTHER WEAK
WAVE WILL DROP THROUGH THE FLOW, BRINGING A 20-50% CHANCE FOR
LIGHT PRECIP ACROSS THE REGION. BRIEF RIDGING BUILDS IN FOR THE
WEEKEND BEFORE ANOTHER WAVE APPROACHES LATE SUNDAY/EARLY MONDAY,
ALTHOUGH THE EXACT DETAILS ARE STILL UNCERTAIN AT THIS TIME.
HIGHS WILL BE GENERALLY IN THE 50S WEDNESDAY THROUGH SATURDAY,
LEANING TOWARDS LOW 50S WEDNESDAY AND THURSDAY AND UPPER 50S
FRIDAY AND SATURDAY. SUNDAY LOOKS TO BE THE WARMEST DAY UNDER THE
RIDGE, WITH HIGHS IN THE 60S. THEN, WITH THE NEXT SYSTEM, HIGHS
WILL FALL BACK INTO THE 50S TO START THE NEXT WEEK. ARCHER
AVIATION
03Z UPDATE...LOW STRATUS, AREAS OF FOG, AND PERIODS OF
DRIZZLE/FREEZING DRIZZLE ARE FORECAST THROUGH THE NIGHT TONIGHT
FOR AREAS WEST OF ROSEBUD COUNTY INCLUDING KBIL/KSHR/KLVM/K6SO/K3HT.
MVFR/IFR CONDITIONS THIS EVENING ARE LIKELY TO DETERIORATE TO
LIFR OCCASIONAL VLIFR AT TIMES AFTER 06Z AND CONTINUE THROUGH 15Z.
WARMER AIR MOVES IN FROM THE SOUTH AROUND SUNRISE WHICH WILL
SHIFT DRIZZLE FREEZING DRIZZLE/FOG OVER TO A PERIOD OF LIGHT SNOW
THROUGH THE MORNING. PRECIPITATION MAY SHIFT OVER TO LIGHT RAIN
BEFORE ENDING AROUND 17Z. MOUNTAIN PASSES AND FOOTHILLS WILL
LIKELY REMAIN OBSCURRED THROUGH THE NIGHT WHILE MOUNTAIN TOPS
SHOULD REMAIN ABOVE THE LOW CLOUDS. LIGHT SNOW SHOWERS WILL PUSH
INTO THE MOUNTAIN TOPS AROUND SUNRISE. CHAMBERS
PRELIMINARY POINT TEMP/POPS
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 031/047 036/053 042/050 041/059 037/057 039/065 041/053
22/J 34/W 78/W 42/W 41/B 01/B 34/W
LVM 028/045 031/050 033/050 031/055 029/056 033/064 032/050
22/J 66/W 77/W 33/W 41/U 12/W 55/W
HDN 030/052 034/055 040/051 038/060 035/056 033/066 037/055
33/J 35/W 88/W 63/W 52/W 11/B 34/W
MLS 035/060 041/058 043/052 040/057 035/056 033/065 039/057
23/L 36/W 78/W 53/W 21/U 01/U 22/W
4BQ 038/064 041/062 043/052 040/057 036/053 035/066 040/058
11/B 24/W 77/W 42/W 21/U 01/U 22/W
BHK 034/058 038/055 041/053 037/055 032/054 030/062 035/057
11/N 24/T 77/W 42/W 21/N 00/U 11/B
SHR 029/057 032/060 035/051 032/059 030/055 029/069 033/057
21/B 24/W 78/W 53/W 53/W 01/U 34/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
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