234
FXUS65 KBYZ 131415
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
815 AM MDT MON OCT 13 2025
KEY MESSAGES
- FOG AND LOW CLOUDS, WITH PATCHY DRIZZLE, LINGER OVER WESTERN
AREAS THROUGH TODAY AND INTO TUESDAY.
- INCREASING CHANCE OF PRECIPITATION TUESDAY NIGHT THROUGH
THURSDAY EVENING. HIGH ELEVATION SNOW ACCUMULATIONS POSSIBLE
(ABOVE 7000FT).
- TURNING MAINLY DRY AND WARMER NEXT WEEKEND.
UPDATE
SATELLITE IMAGERY SHOWS A LARGE AREA OF LOW STRATUS OVER MUCH OF
THE REGION. WESTERN CONUS TROF CONTINUES TO PRODUCE LIGHT SNOW
OVER CENTRAL MT, INCLUDING PORTIONS OF OUR NW CWA, BUT IT IS
MOSTLY LOW CLOUD WE ARE DEALING WITH AS ASCENT IS FOCUSED
PRIMARILY TO OUR WEST. K1KM (HARLOWTON) CONTINUES TO SHOW
INTERMITTENT BOUNCING BETWEEN LIGHT SNOW AND DRIZZLE, AND FORECAST
SOUNDINGS INDEED SHOW A DEEP ENOUGH SATURATED BOUNDARY LAYER
WHICH (WITH HEALTHY UPSLOPE WINDS) SHOULD CONTINUE TO PROVIDE A
RISK OF DRIZZLE. OF COURSE, EARLY THIS MORNING WHERE TEMPS ARE
BELOW 32F THIS IS IN THE FORM OF FREEZING DRIZZLE, E.G. OVER
WHEATLAND COUNTY, WITH POTENTIAL IMPACTS TO TRAVEL ON US-191.
OTHERWISE, ANY RISK OF ACCUMULATING LIGHT SNOW HAS JUST ABOUT
ENDED.
UPSLOPE FOG/STRATUS IS GOING NOWHERE IN OUR WEST TODAY AND TEMPS
FROM LIVINGSTON TO HARLOWTON WILL LIKELY NOT CLIMB OUT OF THE 30S,
WITH 40S CENTRAL AND LOW 50S EAST FOR HIGHS TODAY. WESTERN AREAS
SHOULD SEE FOG/STRATUS EXPAND AGAIN TONIGHT. JKL
DISCUSSION
TODAY THROUGH TUESDAY NIGHT...
CHILLY MORNING AHEAD AS SHALLOW EASTERLY FLOW AND COLD AIR MASS
HAVE SETTLED OVER OUR REGION. READINGS WILL BE IN THE MID 20S WEST
TO MID 30S EAST FOR THE MORNING RUSH. DRESS THE KIDS WARM THIS
MORNING! WE DO HAVE SOME LIGHT SNOW OCCURRING OVER THE WHEATLAND
COUNTY AREA SINCE LAST EVENING, WITH AN INCH OR TWO OF
ACCUMULATION POSSIBLE FROM NEAR MELVILLE TO JUDITH GAP. AN INCH
OR TWO OF ACCUMULATION IS POSSIBLE (50% CHANCE OF AN INCH)...AND
MAY PRODUCE MINOR IMPACTS (SLICK ROADS/LIMITED VISIBILITY). LOW-
MID LEVEL MOISTURE LIFTS NORTH/NORTHWEST TODAY AS 500 MB RIDGE
BUILDS OVER THE REGION, AND WITH WEAKENING UPSLOPE THE LIGHT SNOW
WILL DWINDLE THROUGH MID MORNING. LOOK FOR A STRATUS CLOUD DECK
OVER THE WESTERN HALF OF THE CWA TO GRADUALLY THIN OUT THROUGH THE
DAY. THIS WILL LIMIT ANY WARM-UP FOR THE MANY AREAS THOUGH, WITH
HIGHS IN THE UPPER 30S AND LOWER 40S WEST TO LOWER 50S EAST.
IN THE MEANTIME TODAY OUT WEST, AN UPPER LOW WILL DROP DOWN ALONG
THE COAST. SOUTHERLY FLOW WILL STRENGTHEN IN RESPONSE FROM THE
DESERT SOUTHWEST INTO THE ROCKIES. THIS WILL PUSH SOME MOISTURE
NORTHWARD INTO OUR REGION. WE COULD SEE A FEW LIGHT SHOWERS OR
VIRGA AS EARLY AS LATE TONIGHT AND EARLY TOMORROW FROM THIS. THE
UPPER LOW SLOWLY STARTS TO SHIFT NORTHEAST INTO NEVADA BY TUESDAY
AFTERNOON. SO LOOK FOR A CONTINUED CHANCE OF ISOLATED LIGHT
SHOWERS OVER OUR AREA (MAINLY WESTERN MOUNTAINS) THROUGH TUESDAY,
AND INCREASING TO A MORE SCATTERED COVERAGE BY TUESDAY NIGHT.
TEMPS WILL REBOUND A BIT TUESDAY RANGING FROM AROUND 50 WEST TO
UPPER 50S EAST...EVEN A FEW LOWER 60S POSSIBLE IN THE SOUTHEAST AS
A WARM TONGUE OF AIR PUSHES NORTH INTO THAT AREA.
WEDNESDAY THROUGH SUNDAY...
ENSEMBLES ARE IN GOOD AGREEMENT THAT UPPER FLOW WILL BECOME
INCREASING DIVERGENT AND MOIST OVER OUR REGION WEDNESDAY AS THAT
UPPER LOW DRIFTS NORTHEAST FROM NEVADA INTO THE CENTRAL ROCKIES.
ASSOCIATED DEFORMATION ZONE SLIDES INTO MONTANA ADDING ADDITIONAL
ASCENT ACROSS OUR REGION INTO WEDNESDAY NIGHT. WIDESPREAD
PRECIPITATION IS EXPECTED DURING THIS TIME WITH ACCUMULATING
SNOWFALL POSSIBLE OVER THE HIGH ELEVATIONS. EC ENSEMBLE MEANS ARE
MORE BULLISH FOR SOUTHERN MT THAN THE GEFS WHICH TAKES THE BETTER
PRECIP AMOUNTS FURTHER NORTH. CLUSTER ANALYSIS SEEMS TO FAVOR THE
GEFS, BUT THIS COULD CHANGE. OVERALL, THE PROBABILITY OF AT LEAST
A HALF INCH OF LIQUID IS 40% OVER ALMOST ALL THE CWA WITH UP TO
70% IN THE HIGH COUNTRY. LOOK FOR TEMPS TO REMAIN SEASONABLY COOL
THROUGH MOST OF THE WEEK IN THE 40S AND 50S. WE MAY SEE UNSETTLED
CONDITIONS YET FRIDAY IN AN UNSTABLE NW FLOW BEFORE WARMER AND
DRIER CONDITIONS ARRIVE THIS WEEKEND. BT
AVIATION
MAIN IMPACT TO AVIATION TODAY AND TONIGHT IS THE LARGE AREA OF LOW
STRATUS CREATING MVFR TO IFR, POSSIBLY DOWN TO LIFR W/ FOG AND
PATCHY LIGHT SNOW OR DRIZZLE ALONG THE EASTERN SLOPES OF THE
MOUNTAINS. PERSISTENT EASTERLY WINDS WILL KEEP STRATUS/FOG ALONG
THE EASTERN SLOPES THROUGH THE DAY, WHILE IMPROVEMENT TO VFR IS
EXPECTED IN THE EAST, EXPANSION OF THE FOG/STRATUS IS EXPECTED
OVER THE WEST AGAIN TONIGHT. EASTERN ASPECTS OF THE MOUNTAINS WILL
REMAIN OBSCURED THROUGH THE PERIOD. EAST WINDS WILL GUST 20-30
KNOTS AT KLVM TODAY. JKL
PRELIMINARY POINT TEMP/POPS
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 042 032/051 037/052 041/052 040/059 037/057 039/065
0/E 12/W 45/W 67/W 42/W 32/W 12/W
LVM 037 025/051 032/050 031/050 032/056 029/057 034/061
1/L 13/W 67/W 76/W 43/W 42/W 13/W
HDN 050 031/053 035/055 040/053 036/061 034/057 034/066
0/B 12/W 45/W 77/W 52/W 42/W 12/W
MLS 051 038/060 041/059 041/052 038/059 036/056 034/064
0/U 11/B 35/W 66/W 43/W 22/W 11/U
4BQ 056 041/063 043/064 042/052 039/058 036/054 035/066
0/U 11/B 33/W 65/W 42/W 22/W 11/U
BHK 052 036/057 038/057 040/055 035/057 032/055 031/064
0/U 11/N 24/W 65/W 42/W 21/N 00/U
SHR 051 030/058 033/061 036/053 033/060 030/055 031/068
0/B 11/B 34/W 77/W 53/W 43/W 11/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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