465
FXUS65 KBYZ 131039
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
339 AM MST SAT DEC 13 2025
KEY MESSAGES
- SNOW BAND SHIFTS TO THE SOUTH AND WEST THIS MORNING FROM BEING
CENTERED ON FORSYTH TO BROADUS AT 6AM TO BEING CENTERED ON
ROUNDUP TO SHERIDAN BY 9AM. LIGHT SNOW AMOUNTS UNDER 1 INCH
EXPECTED FOR THESE AREAS BETWEEN 6 AND 12 AM.
- COLD CONDITIONS CONTINUE TODAY WITH HIGH TEMPERATURES IN THE
SINGLE DIGITS AND TEENS FOR THE LOWER ELEVATIONS (EASTERN MT).
- WARMER AND DRIER WEATHER EXPECTED TO RETURN BY SUNDAY THROUGH
EARLY NEXT WEEK. EXPECT RAPID SNOWMELT INTO EARLY NEXT WEEK.
- PERIODS OF STRONG WINDS FOR FOOTHILLS GAP LOCATIONS INCLUDING
LIVINGSTON AND NYE STARTING TONIGHT AND LASTING THROUGH THE
FORESEEABLE FUTURE. STRONG WINDS ACROSS SOUTHEAST MONTANA
WEDNESDAY.
DISCUSSION
TODAY THROUGH SATURDAY...
THE SNOW BAND IS EXPECTED TO DRIFT TO THE SOUTH AND WEST THIS
MORNING FROM BEING CENTERED ON FORSYTH TO BROADUS AROUND 6 AM TO
ROUNDUP TO SHERIDAN BY 9 AM. THIS SNOW BAND WILL ONLY BE REMNANTS
OF THE STRONG BAND WE HAVE EXPERIENCED OVER THE LAST FEW DAYS
WITH ADDITIONAL SNOW AMOUNTS EXPECTED TO REMAIN UNDER 0.5 INCHES.
THE NBM IS GIVING LOCATIONS IN BIGHORN COUNTY THE BEST CHANCE
(10-30%) OF RECEIVING GREATER THAN 0.5 INCHES OF SNOW FROM THIS
BAND.
WIND WILL BE THE MAIN IMPACT OVER THE NEXT 7 DAYS. TONIGHT INTO
SUNDAY MORNING WILL SEE THE IDAHO FALLS TO LEWISTOWN PRESSURE
GRADIENT INCREASE INTO THE 13-16 MB RANGE WITH 700 MB WINDS OF
30-35 KTS. THIS BRINGS A 50-75% CHANCE FOR WINDS GREATER THAN 60
MPH FOR GAP AREAS SUCH AS LIVINGSTON AND NYE. IT WILL BE A SIMILAR
SETUP SUNDAY NIGHT INTO MONDAY WITH WIND GUSTS NEAR 60 MPH. 700
MB WINDS CONTINUE TO INCREASE THROUGHOUT THE DAY MONDAY WITH A
PRESSURE GRADIENT GETTING INTO THE 15-20 MB RANGE. THIS IS LEADING
TO LOCAL WIND GUIDANCE GIVING LIVINGSTON A 30% AND 60% CHANCE OF
GETTING A WIND GUST OVER 75 MPH MONDAY NIGHT INTO TUESDAY AND
TUESDAY NIGHT INTO WEDNESDAY. PERIODS OF STRONG WINDS ARE EXPECTED
TO CONTINUE THROUGH THE END OF THE WEEK.
WEDNESDAY, AN INTENSE CLIPPER SYSTEM IS EXPECTED TO PASS THROUGH
SOUTHERN ALBERTA AND SASKATCHEWAN. ITS MAIN IMPACT WILL BE TO
BRING STRONG WINDS ACROSS SOUTHEAST MONTANA. THE DETERMINISTIC GFS
IS INDICATING 700 MB WINDS OF 70-90 KTS AND 850 MB WINDS OF 50-60
KTS. ECMWF METEOGRAMS ARE SHOWING WINDS NEAR TO ABOVE 50 KTS
ACROSS THE FORECAST AREA. EFI TABLES SHOW VALUES OF 0.8-0.9
INDICATING AN ANOMALOUS EVENT. THE NBM IS GIVING THE PLAINS OF
EASTERN MONTANA A GREATER THAN 50% CHANCE FOR A WIND GUST OVER 50
MPH. STRONG WINDS CAN ALSO BE EXPECTED ALONG THE FOOTHILLS WITH
LOCAL GUIDANCE GIVING BIG TIMBER AND HARLOWTON 40-50% CHANCES OF
GETTING A GUST OVER 60 MPH. PRECIPITATION POTENTIAL HAS INCREASED
WITH THIS SYSTEM WITH THE NBM GIVING LOWER ELEVATIONS A 20-40%
CHANCE OF RECEIVING GREATER THAN 0.1 INCHES OF PRECIPITATION.
TEMPERATURES REMAIN COLD FOR MUCH OF THE REGION TODAY WITH
TEMPERATURES IN THE SINGLE DIGITS AND TEENS EAST OF BILLINGS.
LOCATIONS ALONG THE FOOTHILLS WILL BE WARMER IN THE 20S AND 30S F
DUE TO DOWNSLOPING WINDS. UPPER LEVEL RIDGING WORKS INTO THE
REGION SUNDAY INCREASING TEMPERATURES SIGNIFICANTLY INTO 40S F FOR
MOST LOCATIONS AND 50S F ALONG THE FOOTHILLS. TEMPERATURES ARE
EXPECTED TO REMAIN SEASONAL OR SLIGHTLY ABOVE SEASONAL OVER THE
NEXT WEEK. A COLD FRONT WEDNESDAY IS EXPECTED TO BRING A BRIEF
COOLDOWN TO THE PLAINS OF EASTERN MONTANA THURSDAY BEFORE
REBOUNDING FRIDAY. TORGERSON
AVIATION
A PASSING DISTURBANCE WILL PUSH COLD AIR AND SNOW BACK TO THE
SOUTHWEST THROUGH THE MORNING HOURS. ALTHOUGH SNOWFALL WILL BE
LESS INTENSE THAN IT HAS BEEN OVER THE PAST 24 HOURS. AS THE COLD
AIR SURGES BACK TO THE WEST, LOW STRATUS, LIGHT SNOW, AND FOG
WILL BRING MVFR TO IFR CONDITIONS BACK INTO CENTRAL AREAS
INCLUDING KBIL AND KSHR. FOR KBIL THE DIMINISHED CONDITIONS WILL
IMPACT THE EARLY MORNING PUSH. EXPECT CONDITIONS TO IMPROVE TO
VFR THROUGH THE AFTERNOON HOURS. SW WINDS WILL INCREASE ALONG THE
WESTERN FOOTHILLS TONIGHT, INCLUDING KLVM, WITH GUSTS OF 30-40
KTS POSSIBLE. STP
PRELIMINARY POINT TEMP/POPS
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 020 010/045 031/046 040/050 036/048 023/041 031/048
5/S 00/B 00/B 01/B 26/O 11/B 23/O
LVM 046 033/055 034/055 041/052 036/048 025/043 031/050
1/B 00/N 00/N 02/R 47/O 12/S 45/O
HDN 020 007/042 021/045 034/048 033/047 020/041 026/048
6/S 00/B 00/B 01/B 26/O 21/B 23/O
MLS 011 001/039 023/041 034/045 029/044 015/035 022/043
5/B 00/U 00/U 00/B 23/O 11/B 11/E
4BQ 018 011/044 026/044 034/049 033/049 020/039 028/048
8/S 00/U 00/U 00/B 14/O 11/B 11/E
BHK 007 904/042 024/045 032/046 027/043 008/030 017/042
2/B 00/U 00/B 00/B 24/O 10/B 11/E
SHR 029 016/053 026/053 034/055 032/051 017/041 025/050
5/S 00/U 00/U 00/B 15/O 21/B 11/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER STORM WARNING IN EFFECT UNTIL 8 AM MST THIS MORNING
FOR ZONES 31-32.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 8 AM MST THIS MORNING
FOR ZONES 33-36-37.
WY...NONE.
WEATHER.GOV/BILLINGS
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