438
FXUS65 KBYZ 170030
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
630 PM MDT TUE SEP 16 2025
KEY MESSAGES
- AREAS OF SHOWERS/THUNDER TONIGHT, LINGERING OVER SOUTHEAST
MONTANA WEDNESDAY.
- LOCALIZED FLOODING OR PONDING OF WATER POSSIBLE TONIGHT IN SOUTH
CENTRAL MT.
- LIGHT SNOW ACCUMULATIONS EXPECTED OVER THE BEARTOOTH MOUNTAINS
ABOVE 10KFT THROUGH WEDNESDAY MORNING. MINOR IMPACTS POSSIBLE
OVER THE HIGHEST ELEVATIONS OF THE BEARTOOTH HIGHWAY.
- BECOMING DRIER WITH A WARMING TREND FOR THE END OF THE WORK
WEEK.
DISCUSSION
A 500 MB TROUGH WILL CONTINUE TO DROP THROUGH THE REGION TONIGHT.
PRECIPITATION WEST OF BILLINGS TODAY WILL BEGIN TO SHIFT TO
LOCATIONS EAST OF BILLINGS OVERNIGHT. AS THE BAND OF PRECIPITATION
BEGINS TO MOVE OFF TO THE EAST, CONDITIONS WILL BECOME LESS
FAVORABLE FOR HIGH ELEVATION SNOW OVER THE BEARTOOTH HIGHWAY. WITH
MANY LOCATIONS IN THE BEARTOOTH/ABSAROKA MOUNTAINS AND SURROUNDING
FOOTHILLS HAVING RECEIVED OVER AN INCH OF RAINFALL OVER THE LAST
24 HOURS, AND THESE SAME LOCATIONS HAVING HIGH CHANCES (40-70%)
FOR AN ADDITIONAL 0.5 INCHES, A MARGINAL RISK FOR EXCESSIVE
RAINFALL HAS BEEN ISSUED FOR LOCATIONS WEST OF BILLINGS. THIS
COULD LEAD TO LOCALIZED FLOODING.
TOMORROW, AS THE UPPER LEVEL LOW CONTINUES TO MOVE EAST, IT WILL
SPIN UP A SURFACE LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS.
THIS LOW WILL ADVECT MOISTURE INTO EASTERN MONTANA BRINGING
PRECIPITATION CHANCES (30-60%) FOR LOCATIONS SOUTH AND EAST OF A
LINE FROM RED LODGE TO BAKER. THURSDAY, THE LOW WILL DRIFT INTO
THE NORTHERN PLAINS BRINGING LINGERING PRECIPITATION CHANCES
(20%) FOR LOCATIONS NEAR THE DAKOTAS BORDER. PRECIPITATION
THROUGHOUT THE NEXT FEW DAYS WILL BE SHOWERS AND GENERAL
THUNDERSTORMS. 6 PM TONIGHT TO 6 PM THURSDAY, LOCATIONS IN CARTER
COUNTY WILL HAVE THE HIGHEST CHANCES (20-50%) FOR GETTING GREATER
THAN 0.5 INCHES OF RAIN WITH <20% CHANCES ELSEWHERE.
THE 500 MB PATTERN WILL REMAIN ACTIVE FRIDAY THROUGH MONDAY WITH
MULTIPLE WAVES MOVING THROUGH. AT THIS TIME, DETERMINISTIC MODELS
AND ENSEMBLES ARE KEEPING THESE SYSTEMS TO THE NORTH WITH LITTLE
TO NO IMPACT OVER OUR REGION. WPC CLUSTERS ARE INDICATING UPPER
LEVEL RIDGING RETURNING NEXT WEEK, THOUGH DETAILS ARE UNCLEAR AT
THIS TIME.
TEMPERATURES WILL GENERALLY BE IN THE 70S F WEDNESDAY THROUGH
FRIDAY. TEMPERATURES INCREASE OVER THE WEEKEND WITH 80S F
RETURNING TO MUCH OF THE REGION. TORGERSON
AVIATION
A FALL WEATHER SYSTEM WILL CONTINUE TO BRING LOWERED CLOUD DECKS,
RAINFALL, AND SCATTERED THUNDERSTORMS TO THE REGION INTO
WEDNESDAY. WITH THIS, THE CORE OF THE PRECIPITATION WILL BE
CENTERED OVER SOUTH-CENTRAL MONTANA AND NORTHERN WYOMING THIS
EVENING INTO TONIGHT AND OVER SOUTH-EASTERN MONTANA AND NORTHERN
WYOMING WEDNESDAY. WHILE VFR CONDITIONS LOOK TO PREVAIL OUTSIDE OF
THIS ACTIVITY, PERIODS OF MVFR CONDITIONS ARE POSSIBLE WITHIN THE
PRECIPITATION, ESPECIALLY UNDER THE HEAVIER SHOWERS AND
THUNDERSTORMS. PERIODS OF MOUNTAIN OBSCURATIONS WILL CONTINUE INTO
WEDNESDAY AS WELL.
OVER THE FOOTHILLS AND PLAINS OF SOUTH-CENTRAL MONTANA, PATCHY
FOG IS POSSIBLE TONIGHT INTO WEDNESDAY MORNING WHERE CLOUD COVER
DECREASES TONIGHT. ARENDS
PRELIMINARY POINT TEMP/POPS
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 052/072 049/076 049/077 053/081 054/079 051/078 051/083
42/B 00/U 00/U 00/B 01/B 20/U 00/U
LVM 042/071 041/077 043/079 046/079 047/074 044/075 045/081
51/U 00/U 00/U 01/B 12/W 11/U 00/U
HDN 050/074 046/076 046/077 048/082 051/080 047/078 046/084
83/W 10/U 00/U 00/B 11/B 20/U 00/U
MLS 055/075 051/073 048/074 049/081 052/079 051/076 049/081
22/W 11/B 10/U 00/B 00/B 20/U 00/U
4BQ 054/067 050/069 046/072 048/080 053/077 052/075 050/080
34/T 21/B 10/U 00/B 00/U 20/U 00/U
BHK 052/071 047/066 044/071 045/078 049/078 048/075 045/079
43/T 22/W 21/B 00/U 00/U 20/U 00/U
SHR 045/065 042/072 043/077 046/080 048/078 045/075 045/081
56/T 21/U 00/U 00/B 11/U 21/U 00/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MDT TONIGHT
FOR ZONE 67.
WY...NONE.
WEATHER.GOV/BILLINGS
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