570
FXUS65 KMSO 121836
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1236 PM MDT MON OCT 12 2026
DISCUSSION
KEY MESSAGES:
- HARD FREEZE COMING FOR THE MORNINGS.
- VALLEY FOG AND STRATUS WILL BE COMMON EARLY THIS WEEK.
- A WARMING AND DRYING TREND THIS WEEK.
- UNSETTLED WEATHER ON THE WAY FOR EARLY NEXT WEEK.
SATELLITE IMAGERY EARLY THIS AFTERNOON INDICATES A CLOSED
CIRCULATION OF LOW PRESSURE OVER EASTERN OREGON AND SOUTHWESTERN
IDAHO. THIS SYSTEM, RESPONSIBLE FOR SENDING PACIFIC MOISTURE
NORTHWARDS INTO SOUTHWEST MONTANA AND NORTH-CENTRAL IDAHO, WILL
TAKE A MORE SOUTHERN ROUTE GOING INTO TUESDAY. IT WILL TAKE
PRECIPITATION WITH IT, LEAVING A POSITIVELY TILTED RIDGE OF HIGH
PRESSURE OVER THE NORTHERN ROCKIES. THAT RIDGE WILL STRENGTHEN
THROUGHOUT THE WEEK, BRINGING DAYTIME TEMPERATURES UP.
TEMPERATURES WILL PEAK ON SATURDAY AT ABOUT 10 DEGREES ABOVE
NORMAL.
IN THE MEANTIME, EXPECT COLD MORNINGS WITH HARD FREEZES LIKELY IN
THE VALLEYS OF WESTERN MONTANA AND MUCH OF NORTH-CENTRAL IDAHO.
THOSE IN THE LOWER VALLEYS OF THE SALMON AND CLEARWATER RIVERS
SHOULD STILL EXPECT FREEZING TEMPERATURES, THOUGH ONLY A FEW
DEGREES OFF THE FREEZING MARK. VALLEY FOG WILL BE ANOTHER HALLMARK
OF THE RIDGE-FOLLOWING-SNOW SCENARIO. MORNING MOTORISTS AND
AVIATORS SHOULD EXPECT FOG FORMATION IN THE VALLEYS.
ENSEMBLES ARE STARTING TO AGREE ON ANOTHER LOW PRESSURE SYSTEM BY
EARLY NEXT WEEK. THOUGH MOST SOLUTIONS ARE ON BOARD WITH A
DISTURBANCE, SOME MEMBERS BRING THE LOW SOUTH, SOME KEEP IT AS AN
OPEN WAVE, AND SOME SHOW A CLOSED LOW. AT THE CURRENT TIME
HORIZON, WE'LL LET THE READER CHOSE THEIR OWN ADVENTURE.
AVIATION
LOW CEILINGS ARE PROVING A CHALLENGE THIS AFTERNOON
AT TERMINALS THAT RECORDED PRECIPITATION, IE KBTM, KHRF, KSMN.
EXPECT STRATUS TO PERSIST AT THOSE TERMINALS THIS AFTERNOON,
GENERALLY KEEPING CEILINGS BELOW 2,000 FT AGL. AS HIGH PRESSURE
BEGINS TO TAKE OVER THIS EVENING, FOG FORMATION IN THE MORNING
WILL BECOME THE NEXT FORECAST CHALLENGE. ADDED FOG INTO THE
12/1800Z TAF FOR KBTM. CONFIDENCE IS A LITTLE LOWER FOR THE OTHER
TAF SITES. FUTURE TAF ISSUANCE MAY SEE FOG ADDED TO KMSN, KHRF,
AND KMSO.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page