575
FXUS65 KBYZ 150908
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
208 AM MST SAT NOV 15 2025
KEY MESSAGES
- WEATHER SYSTEM LATE SUNDAY INTO MONDAY WILL LOWER TEMPERATURES
TO NEAR NORMAL WITH AN INCREASED CHANCE OF PRECIPITATION.
- FURTHER COOLING AND UNSETTLED CONDITIONS MIDDLE PART OF NEXT
WEEK.
DISCUSSION
TODAY THROUGH FRIDAY...
CURRENT ANALYSIS AND SATELLITE IMAGERY INDICATED BROAD LOW
AMPLITUDE TROUGH AXIS WAS SLIDING EAST INTO THE DAKOTAS OVERNIGHT.
ASSOCIATED UPPER DYNAMICS WERE ALSO MOVING EAST OF MONTANA
BRINGING SHOWER ACTIVITY TO AN END.
FOR TODAY...A FRONTAL BOUNDARY WILL SAG ACROSS EAST CENTRAL
MONTANA UNDER NW FLOW ALOFT. A WEAK PERTURBATION IN THE FLOW WILL
TRACK NW TO SE ACROSS OUR EASTERN ZONES THIS MORNING AND MODELS
HAVE TRENDED TOWARD PRODUCING SOME LIGHT PRECIP UNDER THIS
FEATURE, SO HAVE INCREASED COVERAGE OF LOW POPS (15-30%) AND
LINGERED THE ACTIVITY INTO THE AFTERNOON NEAR THE DAKOTA BORDER.
LOOK FOR DECREASING CLOUDS FROM WEST TO EAST THIS AFTERNOON. HIGHS
WILL BE IN THE LOWER 60S WEST TO NEAR 50 FAR EAST. RIDGING WILL
BUILD BACK IN TONIGHT AND SUNDAY FOR MILD DRY CONDITIONS. HIGHS
SUNDAY WILL BE IN THE 50S TO AROUND 60 DEGREES.
LATE SUNDAY THROUGH MONDAY NIGHT...A SLOW MOVING UPPER TROUGH
WILL TRACK ACROSS WYOMING FOR THE LATTER PART OF THE WEEKEND AND
INTO MONDAY. MODELS GENERALLY PUSH SOME MOISTURE UP FROM THE SOUTH
INTO OUR FORECAST AREA, BUT ARE IN A LITTLE BETTER AGREEMENT
ABOUT KEEPING THE BULK OF THE ENERGY TO OUR SOUTH BEFORE IT TRACKS
INTO SD/NEBR. THEREFORE, WE ANTICIPATE A LOW IMPACT EVENT FOR US
WITH ABOUT 2-5 INCHES OF SNOW POSSIBLE IN THE BEARTOOTHS (MAINLY
ABOVE 7500 FT), AND SCATTERED RAIN SHOWERS OVER THE LOWER
ELEVATIONS THROUGH MONDAY. THERE IS A 25-60% CHANCE OF AT LEAST
0.25 INS OF LIQUID PRECIP, HIGHEST OVER OUR WESTERN MOUNTAINS.
HIGHS WILL BE IN THE 50S MONDAY, AND AGAIN TUESDAY.
WEDNESDAY THROUGH FRIDAY...A SPLIT FLOW PATTERN TO OUR WEST WILL
SHIFT EAST ACROSS THE ROCKIES. THIS IS LIKELY TO LEAD TO TEMPS
COOLING DOWN TO AROUND SEASONAL NORMS (HIGHS 40S) WITH A CHANCE
OF SHOWERS AND MOUNTAINS SNOW. IT DOES NOT CURRENTLY APPEAR TO
RESULT IN A BIG PRECIP EVENT FOR US, BUT CLUSTER ANALYSIS OF
ENSEMBLES SUGGEST A GOOD DEAL OF UNCERTAINTY YET. BT
AVIATION
09Z DISCUSSION...
SOME MOUNTAIN WAVE ACTIVITY COULD LINGER OVERNIGHT TONIGHT CLOSE
TO THE HIGH TERRAIN. KSHR MAY SEE SOME IMPACTS FROM THIS IN TERMS
OF LLWS AND A STRAY GUST TO 30KTS OUT OF THE WEST. KBIL MAY ALSO
SEE SOME LLWS THROUGH SUNRISE THIS MORNING.
ISOLATED SHOWERS LINGER ACROSS THE ENTIRE REGION WITH THE HIGHEST
CONCENTRATION OVER FAR SOUTHEAST MONTANA AT THIS TIME. THROUGH THE
MORNING HOURS ANOTHER PUSH OF SCATTERED SHOWERS COULD MOVE
THROUGH ALL SITES WITH THE HIGHEST LIKELIHOOD BEING AT KBIL (20%
CHANCE). SOME FOG AND LOW CLOUDS HAVE FORMED IN THE PLAINS WHICH
HAS KMLS AND KBHK AT OR NEAR IFR CONDITIONS. THIS IS FORECAST TO
CONTINUE THROUGH SUNRISE, AND A DIP INTO LIFR CONDITIONS IS
POSSIBLE AS WELL. MOUNTAINS WILL BE OBSCURED THROUGH AT LEAST
20Z. WMR
PRELIMINARY POINT TEMP/POPS
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 064 038/055 038/056 038/055 035/049 029/049 031/049
2/W 00/E 13/W 32/W 23/W 10/B 11/B
LVM 061 035/057 037/055 036/053 032/049 029/050 027/048
0/N 01/E 24/W 33/W 33/W 11/B 21/U
HDN 063 035/059 036/054 036/055 032/049 026/049 027/049
2/W 00/E 14/W 42/W 34/W 21/B 11/B
MLS 054 031/056 036/051 034/052 033/049 029/048 028/048
2/B 00/B 02/W 31/B 22/W 10/B 00/B
4BQ 059 035/059 038/051 037/053 034/049 030/048 029/047
0/B 00/B 13/W 21/B 12/W 20/B 01/B
BHK 050 029/055 033/047 030/050 029/049 026/047 026/046
2/W 00/B 13/W 31/B 12/W 20/B 00/B
SHR 061 033/059 034/052 031/054 031/049 026/050 025/048
0/B 00/B 25/W 32/W 23/W 21/B 11/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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