281  
FXUS65 KBYZ 291451  
AFDBYZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BILLINGS MT  
851 AM MDT SAT MAR 29 2025  
   
KEY MESSAGES  
 
- COOLER & WETTER THROUGH THE WEEKEND, WITH AREAS OF RAIN AND WET  
SNOW; GREATEST POTENTIAL FOR SNOW ACCUMULATION AT LOWER  
ELEVATIONS IS SATURDAY NIGHT AND SUNDAY.  
 
- UNSETTLED CONDITIONS ARE FORECAST TO PERSIST THROUGH NEXT WEEK  
WITH MULTIPLE ROUNDS OF PRECIPITATION. THERE IS A MEDIUM TO HIGH  
CHANCE (25-75%) FOR GREATER THAN 0.25 INCHES TUESDAY/WEDNESDAY.  
 
 
   
UPDATE  
 
HAVE ADDED THE LIVINGSTON AREA TO OUR WINTER WEATHER ADVISORIES  
IN OUR WEST, BEGINNING AT 6PM THIS EVENING.  
 
SATELLITE IMAGERY SHOWS A SHORTWAVE TO OUR SOUTH MOVING FROM  
NORTHEAST CO INTO NE, AND AN UPSTREAM WAVE MOVING FROM WA/OR INTO  
ID. THE FORMER CONTINUES TO PRODUCE SOME LIGHT SNOW (W/ A DUSTING  
OF ACCUMULATION PER WEB CAMERAS) OVER SOUTHEAST MT. THE LATTER  
WILL BRING US SOME WET SNOW TONIGHT & SUNDAY. IN THE MEANTIME,  
ALTHOUGH WE ARE IN A LIGHT WIND REGIME WITH WEAK FORCING, THERE IS  
AN AREA OF LOW LEVEL FRONTOGENESIS PRODUCING SHALLOW LIGHT RAIN &  
SNOW FROM WHEATLAND/MUSSELSHELL INTO WESTERN YELLOWSTONE  
COUNTIES. THE BILLINGS AIRPORT HAS RECENTLY DROPPED TO 32F AND IS  
REPORTING LIGHT SNOW. THE FRONTOGENESIS SHOULD WANE OVER THE NEXT  
FEW HOURS AS LOW LEVEL FLOW BECOMES A MORE UNIFORM EASTERLY, BUT  
THIS WILL NEED TO BE WATCHED. TEMPERATURES HAVE ALSO COOLED MORE  
THAN PREVIOUSLY THOUGHT WITH MID 20S EAST TO MID 30S WEST AS OF  
845AM. WITH THE EASTERLY FLOW AND ABUNDANCE OF THICK/LOW CLOUD  
COVER, TEMPS WILL STRUGGLE TO RISE TODAY AND WILL PROBABLY NOT  
RISE ABOVE THE UPPER 30S/LOWER 40S MOST PLACES. HAVE MADE SOME  
ADJUSTMENTS TO POPS/WX AND TEMPS. JKL  
 
 
   
DISCUSSION  
 
TODAY THROUGH SUNDAY NIGHT...  
 
WEAK UPPER LEVEL RIDGING IS MOVING OUT OF THE REGION TODAY, AHEAD  
OF AN APPROACHING TROUGH. A SERIES OF FRONTS CAME THROUGH THE  
REGION ON FRIDAY, BRINGING A SURFACE WIND SHIFT TO THE EAST-  
NORTHEAST AND COOLER TEMPERATURES. HIGH TEMPERATURES WILL BE IN  
THE 30S AND 40S TODAY AND SUNDAY. A SLOW MOVING BAND OF  
PRECIPITATION IS LOCATED BETWEEN SHERIDAN COUNTY AND NORTHERN  
ROSEBUD COUNTY, THIS BAND WILL CONTINUE TO MOVE EAST THROUGH THE  
EARLY MORNING HOURS. RADAR AND MELTING LAYER OBSERVATIONS INDICATE  
SOME HEAVIER SHOWERS IN THIS BAND, POTENTIALLY PRODUCING SOME  
SMALL GRAUPEL.  
 
IN THE NORTHWESTERN ZONES, HEAVY PRECIPITATION CONTINUES,  
ESPECIALLY IN THE CRAZY MOUNTAINS WHERE A WINTER STORM WARNING  
CONTINUES UNTIL 6PM SUNDAY. THE SOUTH FORK SHIELDS SNOTEL ON THE  
WESTERN SIDE OF THE CRAZIES HAS REPORTED 0.3 INCHES OF SNOW WATER  
EQUIVALENT SO FAR. A RAIN/SNOW MIX HAS ALSO BEEN ONGOING FOR  
IN THE MELVILLE FOOTHILLS, NORTHERN SWEETGRASS, AND WHEATLAND  
COUNTIES, WHERE A A FEW TENTHS TO AN INCH OF SNOW HAS BEEN  
RECORDED BY MONTANA MESONET SITES. THE RAIN/SNOW MIX IS FORECAST  
TO CONTINUE THROUGH TODAY, WITH DAY TIME TEMPERATURES IN THE MID  
30S.  
 
THE CHANCE FOR PRECIP WILL SLIGHTLY DECREASE AHEAD OF TWO WAVES  
(ONE THIS AFTERNOON AND ONE EARLY SUNDAY). WITH THE FIRST WAVE,  
THE FIRST AREAS TO SEE AN INCREASE IN PRECIP WILL BE THE  
NORTHWESTERN ZONES AND THE WESTERN FOOTHILLS, AS WELL AS THE  
SOUTHEAST. THE RAIN/SNOW MIX WILL SPREAD ACROSS THE PLAINS, INTO  
THE EASTERN ZONES, WHILE THE WESTERN ZONES WILL SEE A TRANSITION  
TO MOSTLY SNOW TONIGHT. THE SECOND WAVE OF ENERGY WILL BRING A  
HIGH CHANCE FOR PRECIP AND HEAVIER ACCUMULATIONS TO THE MOUNTAINS  
AND FOOTHILLS. THE CHANCE FOR PRECIP IN THE LOWER ELEVATIONS WILL  
BE MODERATE TO HIGH MAINLY WEST OF ROSEBUD COUNTY.  
 
AS A RESULT OF THE MENTIONED TRANSITION TO SNOW, WINTER WEATHER  
ADVISORIES HAVE BEEN ISSUED ALONG THE BEARTOOTH/RED LODGE  
FOOTHILLS, NORTHERN SWEETGRASS, AND WHEATLAND COUNTY. AMOUNTS FOR  
THESE ADVISORIES VARY, WITH 2-5 INCHES POSSIBLE IN THE FOOTHILLS  
AND AND 1-3 INCHES POSSIBLE FOR NORTHERN SWEETGRASS AND WHEATLAND  
COUNTY. A WINTER WEATHER ADVISORY FOR THE MELVILLE FOOTHILLS  
CONTINUES UNTIL 6PM SUNDAY, WITH AN ADDITIONAL 3-6 INCHES OF  
SNOWFALL FORECAST.  
 
PATCHY FOG IS POSSIBLE IN THE NORTHWEST WHERE PRECIPITATION IS  
OCCURRING, AS WELL AS LOW VALLEYS IN THE PLAINS WHERE SHOWERS  
MOVED THROUGH THIS MORNING.  
 
SUNDAY AFTERNOON, PRECIPITATION WILL END ACROSS THE AREA, WITH  
A BRIEF PERIOD OF UPPER LEVEL RIDGING BUILDING OVER THE REGION  
INTO MONDAY.  
 
MATOS  
 
MONDAY THROUGH FRIDAY...  
 
ENSEMBLES AND CLUSTER ANALYSIS CONTINUE TO POINT TO AN ACTIVE LONG  
TERM, WITH LOWER HEIGHTS PERSISTING OVER THE NORTHERN ROCKIES.  
MULTIPLE DISTURBANCES ARE FORECAST TO MOVE THROUGH THE REGION WITH  
NEAR TO BELOW NORMAL TEMPERATURES.  
 
MOST OF THE AREA WILL SEE DRY CONDITIONS DURING THE DAY MONDAY  
WITH SHORTWAVE RIDGING IN PLACE. LARGE SCALE TROUGHING MOVING EAST  
THROUGH THE WEST WILL INTRODUCE SOUTHWEST FLOW TO WESTERN AREAS  
DURING THE AFTERNOON AND EVENING, WITH AN EMBEDDED WAVE FORECAST  
TO LIFT INTO THE REGION MONDAY NIGHT AND TUESDAY. RAIN/SNOW  
CHANCES (40-90%) SPREAD OUT ACROSS THE AREA TUESDAY, LINGERING  
INTO TUESDAY NIGHT/WEDNESDAY OVER SOUTHEAST MT AS THE WAVE  
EVENTUALLY WRAPS UP INTO A LOW OVER NORTHEAST WY/NORTHWEST SD.  
PRECIPITATION AMOUNTS LOOK TO RANGE FROM 0.10 INCHES TO 0.50  
INCHES MONDAY NIGHT THROUGH WEDNESDAY, WITH HIGHER TOTALS OVER THE  
MOUNTAINS. CURRENTLY, THE NBM HAS A PROBABILITY OF 25-75% OF  
EXCEEDING 0.25 INCHES OF PRECIPITATION DURING THE TIMEFRAME,  
GREATEST OVER THE MOUNTAINS AND FOOTHILLS. THIS EQUATES TO SEVERAL  
INCHES OF SNOW IN THE MOUNTAINS, WITH LIGHT ACCUMULATIONS OVER THE  
HIGHEST HILLS OVER THE LOWER ELEVATIONS. THE PROBABILITY OF  
GETTING 6 OR MORE INCHES OF SNOW IN THE MOUNTAINS IS CURRENTLY  
40-70%, GREATEST OVER THE BIGHORNS. ADDITIONAL RAIN/SNOW CHANCES  
ARE POSSIBLE FOR THURSDAY AND FRIDAY AS A DEEP TROUGH REMAINS IN  
PLACE OVER THE WEST ALLOWING FOR DISTURBANCES TO MOVE THROUGH THE  
REGION. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE 40S AND  
LOWER 50S MOST DAYS. STP  
 
 
   
AVIATION  
 
AREAS OF LIGHT RAIN AND SNOW, LOW CLOUDS AND LOCALIZED FOG, WILL  
RESULT IN WIDESPREAD POOR FLYING WEATHER TODAY (MVFR TO LIFR).  
GRADUAL IMPROVEMENT IS EXPECTED THIS AFTERNOON, BUT ANOTHER ROUND  
OF MOSTLY WET SNOW WILL SPREAD IN FROM THE WEST TONIGHT, ALLOWING  
WIDESPREAD IFR OR LOWER FOR MUCH OF TONIGHT AND EARLY SUNDAY.  
MOUNTAINS WILL REMAIN OBSCURED THROUGH THE PERIOD. JKL  
 
 
   
PRELIMINARY POINT TEMP/POPS  
 
TDY SUN MON TUE WED THU FRI  
-------------------------------------------------------  
BIL 041 031/040 030/056 035/048 035/052 031/053 032/048  
6/O 37/O 14/R 57/O 43/O 13/R 23/O  
LVM 046 031/040 030/051 033/042 028/045 028/048 028/045  
4/R 76/O 26/O 67/S 32/S 23/S 33/S  
HDN 042 030/041 027/058 033/048 032/052 028/055 029/050  
4/R 35/O 13/R 57/R 54/O 23/R 23/O  
MLS 040 029/040 028/053 032/048 032/051 030/055 031/052  
2/O 22/O 11/B 44/R 32/O 11/B 11/B  
4BQ 038 030/038 029/051 030/049 032/047 030/053 031/050  
6/O 43/O 21/B 35/O 53/O 12/R 12/R  
BHK 038 023/038 023/046 028/047 028/046 025/053 028/050  
2/E 41/E 11/N 35/O 53/S 11/B 12/R  
SHR 041 028/039 024/055 028/047 028/046 023/049 025/047  
6/R 58/O 22/R 38/O 65/O 23/R 23/R  
 
 
   
BYZ WATCHES/WARNINGS/ADVISORIES  
 
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 6  
PM MDT SUNDAY FOR ZONES 34-56-63-65-66-141-228.  
WINTER STORM WARNING IN EFFECT UNTIL 6 PM MDT SUNDAY FOR ZONE  
68.  
WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MDT SUNDAY FOR  
ZONE 172.  
WY...NONE.  
 
 
 
 
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