107
FXUS65 KBYZ 302040
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
240 PM MDT SUN MAR 30 2025
KEY MESSAGES
- PRECIPITATION TAPERS OFF THIS AFTERNOON & EVENING; LOW CLOUDS
AND LOCALIZED FOG PERSIST THROUGH THE NIGHT INTO EARLY MONDAY
(PLEASE ALLOW EXTRA TIME FOR YOUR MORNING COMMUTE).
- ANOTHER ROUND OF MOUNTAIN SNOW WILL IMPACT ALL MOUNTAIN RANGES
LATE MONDAY THROUGH WEDNESDAY. TOTALS WILL BE BETWEEN 8-14"
- MIXED RAIN AND SNOW IS EXPECTED FOR MOST OF THE AREA MIDWEEK.
- UNCERTAINTY REMAINS AROUND THE LATE WEEK SYSTEM, STAY TUNED TO
THE FORECAST.
DISCUSSION
THROUGH MONDAY NIGHT...
SNOW IS TAPERING OFF ALONG THE WESTERN FOOTHILLS, AND AS TEMPS
RISE BACK TO THE LOWER 30S WE ARE SEEING SNOW MELT AND ROADS
BECOME JUST WET. FOR THESE REASONS HAVE CANCELLED ALL WINTER
HIGHLIGHTS OVER OUR WESTERN ZONES. BASED ON MT MESONET STATIONS
AND WEB CAMERAS, IT LOOKS AS IF MOST PLACES RECEIVED 1-3" OF SNOW,
W/ PERHAPS UP TO 4-5" ALONG THE FOOTHILLS. THE BILLINGS AIRPORT
HAS PICKED UP 0.27" OF WATER EQUIVALENT AS OF 19Z...A GOOD DRINK
OF WATER.
SATELLITE IMAGERY CONTINUES TO SHOW DIFFLUENT FLOW BUT TOPS ARE
WARMING CONSIDERABLY IN OUR WEST NOW. BLX CONTINUES TO SHOW A DEEP
VEERING WIND PROFILE W/ UPSLOPE FLOW THROUGH 10-12KFT, SO IT WILL
KEEP SNOWING IN THE METRO AREA FOR AT LEAST A COUPLE MORE HOURS.
PRECIP HAS SPREAD TO SHERIDAN AND MILES CITY BUT TEMPS ARE WARMER
AND SNOW IS IS BARELY ACCUMULATING IF AT ALL. TEMPS TODAY HAVE
REMAINED CHILLY AND MOST LOCATIONS ARE IN THE UPPER 20S AND LOWER
30S...THOUGH THEY ARE BEGINNING TO CLIMB SLOWLY.
AS PRECIPITATION TAPERS OFF OVER THE NEXT SEVERAL HOURS (AREAS OF
LIGHT SNOW AND FLURRIES WILL LIKELY LINGER INTO THE EVENING) THE
ATTENTION TURNS TO FOG POTENTIAL TONIGHT. BOUNDARY LAYER WINDS
WILL REMAIN EASTERLY AND THUS STRATUS SHOULD REMAIN OVER THE
REGION THROUGH THE NIGHT. HOWEVER, ANY BREAKS IN THE LOW CLOUD
COVER WILL ALLOW FOG TO DEVELOP QUICKLY...AND IF THAT HAPPENS IT
COULD BE DENSE. GREATEST CHANCE OF FOG IS OVER CENTRAL AND WEST
PARTS WHERE PRECIP HAS BEEN HEAVIEST. NOT SURE HOW EXACTLY THIS
WILL EVOLVE TONIGHT SO IT WILL NEED TO BE MONITORED. IF THE
BOUNDARY LAYER IS SATURATED THROUGH A DEEP ENOUGH LAYER, CANNOT
RULE OUT PATCHY FREEZING DRIZZLE ONCE MID LEVELS BEGIN TO DRY.
NONE OF THE HIGH RES MODELS SHOW DRIZZLE, AND FORECAST SOUNDINGS
ARE MORE SUGGESTIVE OF A SHALLOWER FOG OR STRATUS, BUT THIS IS
ANOTHER ITEM TO WATCH TONIGHT. AS TEMPS FALL BACK BELOW FREEZING
SOME WET ROADS COULD TURN ICY. GIVEN ALL OF THIS, PLEASE ALLOW
EXTRA TIME FOR YOUR MONDAY MORNING COMMUTE.
WE WILL SEE A PERIOD OF LOW AMPLITUDE RIDGING TONIGHT, BUT HEIGHTS
BEGIN TO FALL AGAIN BY EARLY TOMORROW AS NEXT PACIFIC TROF BEGINS
TO MOVE INLAND. TOMORROW WILL BE QUITE A BIT WARMER THAN TODAY
(HIGHS IN MID 40S TO MID 50S), BUT BY AFTERNOON THE CHANCE OF
SHOWERS WILL BEGIN TO INCREASE FROM THE WEST. THERE IS A 20-50%
CHANCE OF SHOWERS MONDAY AFTERNOON AND NIGHT. THE WESTERN
MOUNTAINS WILL SEE A RETURN TO ACCUMULATING SNOWFALL BY EVENING.
ALSO, CANNOT RULE OUT A FEW RUMBLES OF THUNDER PER THE DIURNAL
INSTABILITY, ESPECIALLY IN OUR FAR W/NW WHERE TEMPS ALOFT WILL
COOL THE FASTEST. PRECIP TYPE AT LOWER ELEVATIONS WILL STAY RAIN
FOR THE MOST PART, BUT WESTERN FOOTHILLS COULD SEE SOME WET SNOW
BY LATE MONDAY NIGHT. SEE EXTENDED DISCUSSION BELOW FOR MORE ON
EXPECTED HEAVY MOUNTAIN SNOW INTO THE MIDWEEK.
JKL
TUESDAY THROUGH SATURDAY...
THE NEXT SYSTEM THAT MOVES INTO OUR AREA WILL BE COURTESY OF A
DIGGING TROUGH THAT MAKES ITS WAY INTO THE FOUR CORNERS REGION.
THE MAIN SURFACE LOW DEVELOPS IN THE LEE OF THE COLORADO ROCKIES
MIDDAY TUESDAY. WHILE THIS WILL AID IN SNOW TOTALS FOR PARTS OF
THE BIGHORN AND PRYOR MOUNTAINS DURING THE SECOND HALF OF THE
EVENT, IT WILL NT BE RESPONSIBLE FOR A A MAJORITY OF THE
PRECIPITATION. AS THE PARENT TROUGH DIGS SE A LOCAL VORT MAX
DEVELOPS OVERTOP OF IT IN EASTERN WA EARLY TUESDAY BEFORE SLIDING
EASTWARD THROUGHOUT THE DAY. PWAT VALUES FOR THE DURATION OF THE
EVENT ARE EXPECTED TO BE OVER 0.3" WITH THE MOISTURE BEING
TRANSPORTED AHEAD OF THE MAIN TROUGH FROM A QUAI-ATMOSPHERIC RIVER
DIRECTLY FROM THE PACIFIC.
SNOW FOR THE WESTERN MOUNTAINS SHOULD START FALLING MONDAY NIGHT
AS THE VORT MAX DEVELOPS AND PUTS ALL OF THE NORTHERN ROCKIES
SQUARELY IN AN AREA OF CVA AND MODEST MOISTURE ADVECTION. SNOW
AND RAIN WILL GRADUALLY SPREAD EASTWARD INTO TUESDAY MORNING
TOWARDS BILLINGS STARTING BEFORE SUNRISE. WITH HIGH TEMPERATURES
MONDAY BEING AVERAGE FOR THIS TIME OF YEAR ACROSS THE CWA, SNOW
WILL HAVE A VERY HARD TIME STICKING TO ANYTHING OTHER THAN GRASSY
SURFACES FOR THE PERIODS THAT IT EVEN FALLS OUTSIDE OF THE
FOOTHILLS. MODEL SOUNDINGS FOR BILLINGS DO SUPPORT A MOSTLY RAIN
SCENARIO, HOWEVER, LOCATIONS WITH EVEN A LITTLE ELEVATION WILL
SEE MUCH HIGHER CHANCES FOR THE P-TYPE TO BE PRIMARILY SNOW.
AS THE SHORTWAVE EXITS THE BIG DEEPENING SURFACE SLOW WILL AID IN
SOME UPSLOPE FOR THE NORTHERN AND NORTHEASTERN SLOPES OF THE
PRYORS AND BIGHORNS. THIS SHORT WINDOW TUESDAY AFTERNOON WILL
FEATURE NORTHERLY TO NORTHEASTERLY WINDS WITH MODIFIED MOISTURE
RETURN RIGHT OFF OF THE GULF. WITH THE WINDOW BEING SHORT, THERE
SHOULD NOT BE ANY MASSIVE TOTALS, HOWEVER, AREAS WITH THIS UPSLOPE
ENHANCEMENT SHOULD HAVE NO TROUBLE SEEING OVER A FOOT OF SNOW.
ADDITIONALLY WITH THIS SFC LOW MOVING THROUGH THE PLAINS, AREAS
IN THE SE PART OF THE CWA WILL NEED TO BE MONITORED FOR THE
POTENTIAL TO SEE ANOTHER COUPLE INCHES DEPENDING ON THE TRACK OF
THE LOW. IT IS WORTH NOTING THAT AREAS IN THE NE PART OF THE CWA
MAY SIMPLY BE TOO FAR REMOVED FROM THE AREAS OF LIFT TO SEE ANY
MEANINGFUL PRECIP AT ALL OUT OF THIS SYSTEM.
THE NEXT SYSTEM MOVES IN LATE WEEK, HOWEVER, THERE IS STILL GREAT
UNCERTAINTY AS ALL LONG RANGE MODELS DO VARY AT LEAST SLIGHTLY
FROM RUN TO RUN. THE CANADIAN HAS STARTED TRENDING TOWARDS THE
EURO SOLUTIONS, WHILE THE GFS REMAINS IN DISAGREEMENT WITH BOTH.
IT DOES APPEAR THAT ANOTHER ROUND OF RAIN/SNOW MIX WITH MOUNTAIN
SNOW IS POSSIBLE FOR THE END OF THE WORK WEEK.
TRENDS CONTINUE TO SHOW A RIDGE DEVELOPING INTO NEXT WEEK WHERE WE
COULD RETURN TO WELL ABOV AVERAGE HIGH TEMPERATURES. WMR
AVIATION
WET SNOW (PRODUCING MVFR TO LIFR) WILL GRADUALLY TAPER OFF THIS
AFTERNOON AND EVENING, BUT POOR FLYING WEATHER WILL CONTINUE
THROUGH TONIGHT AND EARLY MONDAY AS EASTERLY UPSLOPE WINDS PROMOTE
LOW CLOUDS AND LOCALIZED FOG AFTER THE PRECIPITATION ENDS. HIGHEST
POTENTIAL FOR FOG IS WEST OF KMLS. IT REMAINS TO BE SEEN WHETHER
THE LOW STRATUS WILL CLEAR ENOUGH TO ALLOW A DENSE FOG TO DEVELOP,
BUT THIS IS SOMETHING TO WATCH. MOUNTAINS WILL REMAIN OBSCURED.
IMPROVEMENT TO WIDESPREAD VFR IS ANTICIPATED MONDAY AS HIGH
PRESSURE ALOFT BUILDS IN FROM THE WEST. JKL
PRELIMINARY POINT TEMP/POPS
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 029/055 033/047 034/049 030/051 032/046 030/055 030/060
22/R 37/O 55/O 24/R 43/O 22/S 10/U
LVM 028/051 032/043 029/045 027/047 029/045 027/051 030/059
25/T 57/S 54/S 24/S 43/S 21/U 00/U
HDN 028/057 031/049 033/048 028/053 029/048 027/054 027/061
21/B 37/R 66/O 24/R 43/O 32/O 10/U
MLS 028/052 033/050 033/045 030/052 029/048 028/054 030/059
11/B 34/R 54/O 11/B 21/B 11/U 00/U
4BQ 028/051 032/047 033/042 028/049 029/047 027/049 029/056
21/B 25/R 66/O 12/R 22/R 22/O 10/U
BHK 024/045 029/044 027/040 025/048 026/047 024/050 025/054
10/N 35/O 65/S 11/B 22/R 11/U 00/U
SHR 024/054 027/047 028/042 021/048 024/043 023/048 024/056
31/B 28/O 77/O 24/R 24/O 43/O 11/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER STORM WATCH IN EFFECT FROM MONDAY EVENING THROUGH
WEDNESDAY AFTERNOON FOR ZONES 67-68.
WINTER STORM WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH
WEDNESDAY AFTERNOON FOR ZONE 171.
WY...WINTER STORM WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH
WEDNESDAY AFTERNOON FOR ZONE 198.
WEATHER.GOV/BILLINGS
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