727
FXUS65 KBYZ 260124
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
724 PM MDT SAT OCT 25 2025
KEY MESSAGES
- GUSTY WINDS OVER THE MOUNTAINS AND FOOTHILLS WEST OF BILLINGS
TONIGHT INTO SUNDAY. WIND GUSTS 40 TO 60 MPH, STRONGEST FROM
LIVINGSTON TO NYE AND IN THE PARADISE VALLEY THIS EVENING.
- WEATHER SYSTEM BRINGS COOLER TEMPERATURES, BREEZY CONDITIONS,
AND THE CHANCE OF PRECIPITATION (20-60%) ACROSS THE AREA TONIGHT
INTO MONDAY. BEST PRECIPITATION EXPECTED OVER THE ABSAROKA-
BEARTOOTH MOUNTAINS (6 TO 10 INCHES OF SNOW). 10-50% CHANCE FOR
GREATER THAN 0.25 INCHES OF PRECIPITATION ACROSS THE REGION.
- DRY CONDITIONS WITH SEASONAL TEMPERATURES TUESDAY THROUGH NEXT
SATURDAY.
UPDATE
PACIFIC TROF CONTINUES TO APPROACH FROM THE WEST AND WE ARE SEEING
STEADY HEIGHT FALLS NOW. PRE-FRONTAL DOWNSLOPE GRADIENTS ARE NOT
VERY TIGHT (7MB FROM IDA-LWT AT 00Z), BUT 700MB WINDS ARE OUT OF
THE SW AT 45-50 KNOTS PER LATEST MESOANALYSIS. THIS HAS RECENTLY
YIELDED 60 MPH GUSTS AT LIVINGSTON (DOT & AIRPORT) AND NEAR NYE. A
WIND ADVISORY CONTINUES IN THESE AREAS UNTIL 3AM, BUT WE SHOULD
SEE DECREASING GUSTS BY MIDNIGHT OR 1AM AS SURFACE TROF AXIS
BEGINS TO SHIFT EAST WITH AN ARRIVING COLD FRONT. WE HAVE ALSO
SEEN SW WINDS INCREASE WITHIN THE PARADISE VALLEY SINCE THE LATE
AFTERNOON, WITH A GUST TO 54 MPH NOTED NEAR EMIGRANT. THIS IS NOT
SURPRISING GIVEN EXISTING PRE-FRONTAL CONDITIONS. FURTHERMORE,
THERE IS A MODEST SIGNAL FOR MOUNTAIN WAVE ACTIVITY IN THE RED
LODGE AREA IN THE 06-09Z TIME PERIOD, BUT THE LOWER AIR MASS SEEMS
TOO UNSTABLE FOR THIS TO BE A LARGER ISSUE. NONETHELESS, SOME
MODELS SHOW MOUNTAIN TOP WINDS INCREASING TO 60-65 KNOTS SO THIS
BEARS WATCHING. HAVE PUSHED FORECAST GUSTS UP TO ~40 MPH AT RED
LODGE AND ROSCOE. THE CHANCE OF REACHING 50 MPH IS ABOUT 15%.
REGARDING PRECIPITATION, COOKE CITY WEB CAMERAS SHOW WHAT LOOKS
LIKE SPRINKLES OCCURRING NOW, WITH TEMPS IN THE MID 40S. FREEZING
LEVELS NEAR 10KFT WILL FALL RAPIDLY OVERNIGHT AND THE BEARTOOTH
ABSAROKAS SHOULD SEE A PERIOD OF MODERATE TO LOCALLY HEAVY
SNOWFALL AS THE TROF MOVES THRU (W/ INCREASING INSTABILITY...NOTE
THE LIGHTNING ACTIVITY IN CENTRAL AND SOUTHERN ID). HAVE ADJUSTED
POPS/WX TO HIT OUR SW MOUNTAINS A BIT HARDER OVERNIGHT. OTHERWISE,
ANY SHOWERS AT LOWER ELEVATIONS WILL REMAIN LIGHT DUE TO STRONG
DOWNSLOPE IMPACTS.
JKL
DISCUSSION
TONIGHT THROUGH FRIDAY...
WIND...
A COLD FRONT ASSOCIATED WITH A CLIPPER SYSTEM WILL DECREASE MIX
DOWN WINDS OVER THE FOOTHILLS TONIGHT. WINDS WILL REMAIN ELEVATED
FOR LIVINGSTON OVERNIGHT HOWEVER DUE TO AN INCREASING IDAHO FALLS
TO LEWISTOWN PRESSURE GRADIENT NEAR 10 MB AND FORECAST SOUNDINGS
INDICATING AN INVERSION SETTING UP. WINDS WILL REMAIN BREEZY
OVERNIGHT FOR MOST FOOTHILLS LOCATIONS DUE TO 700 MB WINDS IN THE
40S KTS AND DOWNSLOPING WINDS PREVENTING THE FORMATION OF A LOW
LEVEL INVERSION FOR MANY LOCATIONS. WIND GUSTS IN THE 30S MPH WILL
BE COMMON DURING THE OVERNIGHT.
WINDS ARE EXPECTED TO INCREASE ACROSS THE FORECAST AREA SUNDAY
WITH THE COLD FRONTAL PASSAGE. 700 MB WINDS OF 30-40 KTS AND
FAVORABLE LAPSE RATES WILL LEAD TO WIND GUSTS INTO THE 30S MPH.
WINDS FOR FOOTHILLS LOCATIONS ARE EXPECTED TO BE IN THE 40S MPH.
THE CHANCE FOR A WIND GUST OVER 40 MPH IS 50-90% FOR LOCATIONS
FROM YELLOWSTONE COUNTY AND WEST WITH 10-30% CHANCES EAST OF
YELLOWSTONE COUNTY.
PRECIPITATION...
PRECIPITATION CHANCES (40-60%) INCREASE IN THE WESTERN FOOTHILLS
TONIGHT BEFORE SPREADING OVER THE LOWER ELEVATIONS SUNDAY (20-30%).
THERE IS A CHANCE (10%) FOR A BRIEF PERIOD OF A RAIN/SNOW MIX
OVER THE FOOTHILLS SUNDAY MORNING WITH RAIN BEING THE DOMINANT
PRECIPITATION TYPE OTHERWISE. SUNDAY NIGHT INTO MONDAY, A SECOND
UPPER LEVEL WAVE MOVES THROUGH THE REGION BRINGING ADDITIONAL
PRECIPITATION CHANCES (20-30%). HIGH PRESSURE WILL CONTINUE TO
MOVE INTO THE REGION SUNDAY NIGHT LEADING TO WIDESPREAD LOW
TEMPERATURES IN THE HIGH 20S TO MID 30S ACROSS THE REGION. THIS
WILL LIKELY BRING A CHANGEOVER TO SNOW FOR THE FOOTHILLS AND A
RAIN/SNOW MIX FOR LOWER ELEVATIONS. THE CHANCE FOR GREATER THAN 1
INCH OF SNOW REMAINS BELOW 10% FOR ALL NON-MOUNTAIN LOCATIONS. THE
CHANCE FOR GREATER THAN 0.25 INCHES OF PRECIPITATION TONIGHT
THROUGH MONDAY IS 10-50% WITH THE BEST CHANCES OVER THE MOUNTAINS
AND FOOTHILLS.
TEMPERATURES ARE EXPECTED TO BE IN THE 50S TO LOW 60S F OVER THE
NEXT WEEK. PREDOMINANT ABOVE AVERAGE 500 MB HEIGHTS IS EXPECTED
TO LEAD TO DRY CONDITIONS. TORGERSON
AVIATION
SW WINDS GUSTING TO 50KTS ALONG THE SW FOOTHILLS (INCLUDING KLVM)
WILL DECREASE TO ~35KTS OVERNIGHT WITH THE ARRIVAL OF A PACIFIC
COLD FRONT. THIS FRONT WILL BRING BRISK SW-W WINDS ACROSS THE
REGION OVERNIGHT INTO SUNDAY. BEHIND THE FRONT, LOOK FOR 30-40KT
GUSTS ALONG ALL WESTERN FOOTHILLS, GUSTS TO 30KTS AT KBIL AND
20-30KTS FURTHER EAST.
VFR WILL PREVAIL AT ALL LOWER ELEVATIONS TONIGHT AND SUNDAY, AS
RAIN SHOWER ACTIVITY ASSOCIATED WITH THE COLD FRONT WILL BE LIGHT.
MOUNTAINS WILL SEE RAIN SHOWERS SWITCH TO ACCUMULATING SNOW AS
FREEZING LEVELS FALL RAPIDLY OVERNIGHT. AS A RESULT, LOOK FOR
MOUNTAINS TO BE FREQUENTLY OBSCURED THROUGH THE PERIOD.
JKL
PRELIMINARY POINT TEMP/POPS
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 044/057 034/051 029/050 031/060 034/055 033/058 043/063
12/W 22/W 00/U 01/B 10/B 00/B 11/B
LVM 035/051 028/044 021/048 027/060 031/054 029/057 039/060
63/W 53/J 00/U 01/B 10/B 00/B 11/N
HDN 042/058 032/052 027/051 027/060 031/055 027/058 037/063
12/W 33/W 00/U 01/B 20/B 00/B 11/B
MLS 044/059 032/052 029/050 026/059 034/053 029/056 038/062
12/W 22/W 00/U 01/B 20/B 00/B 11/B
4BQ 046/058 035/049 030/048 027/058 034/052 030/056 037/062
01/B 33/W 00/U 00/B 10/B 00/B 01/B
BHK 042/059 032/050 026/048 022/055 029/052 025/052 031/060
01/N 33/W 10/U 00/B 10/B 00/B 01/B
SHR 039/058 029/047 023/048 022/060 029/053 026/057 033/063
11/B 34/W 10/U 00/B 21/B 00/B 11/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WIND ADVISORY IN EFFECT UNTIL 3 AM MDT SUNDAY FOR ZONES
65-66.
WY...NONE.
WEATHER.GOV/BILLINGS
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