125
FXUS65 KBOI 150335
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
835 PM MST WED JAN 14 2026
DISCUSSION
NO CHANGE TO CURRENT FORECAST, WITH UPPER LEVEL
RIDGE FORECAST TO STAY STRONG OVER THE NORTHWESTERN US THE NEXT
SEVERAL DAYS. DENSE FOG ADVISORY FOR THE LOWER TREASURE VALLEY
LOOKS FINE AS LATEST OBS AND SATELLITE IMAGERY SHOW FOG ALREADY
IN THE ADVISORY AREA. DENSE FOG LIKELY AGAIN THERE NEXT TWO
NIGHTS, AS WELL. AIR STAGNATION WILL ALSO CONTINUE IN THE
VALLEYS THROUGH AT LEAST EARLY MONDAY MORNING AND POSSIBLY
THROUGH WEDNESDAY.
AVIATION
MVFR-LIFR CONDITIONS AND MOUNTAIN OBSCURATION IN
AREAS OF FOG/LOW STRATUS OVERNIGHT WEDNESDAY INTO THURSDAY
MORNING/EARLY AFTERNOON, MAINLY IN SHELTERED MOUNTAIN VALLEYS
AND LOWER BASINS. PERSISTENT LIFR FREEZING FOG OVER LOWER
TREASURE VALLEY OVERNIGHT THROUGH THURSDAY MORNING. SURFACE
WINDS: LIGHT AND VARIABLE UNDER 7 KT OVERNIGHT THROUGH
THURSDAY MORNING. WINDS ALOFT AT 10KFT MSL: W- NW 10-20 KT.
KBOI...VFR. LIFR FOG DEVELOPING TONIGHT THROUGH THURSDAY LATE
MORNING. CHANCES DIMINISH THURSDAY AFTER 18Z. SURFACE WINDS:
LIGHT AND VARIABLE.
AIR STAGNATION
STAGNANT CONDITIONS CONTINUE OVER THE NEXT
SEVERAL DAYS WITH POOR MIXING AND A TEMPERATURE INVERSION
CONTINUING IN THE LOWER VALLEYS.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...A RIDGE REMAINS
OVER THE AREA WITH STAGNANT CONDITIONS AND A TEMPERATURE
INVERSION. PATCHY FOG REMAINS ALONG IN THE LOWER TREASURE VALLEY
ALONG THE SNAKE RIVER. FOG IS EXPECTED TO DISSIPATE BRIEFLY
THIS AFTERNOON BEFORE REDEVELOPING AFTER SUNSET AND SLOWLY
EXPANDING TONIGHT INTO THURSDAY MORNING. A DENSE FOG ADVISORY
HAS BEEN ISSUED FOR THE LOWER TREASURE VALLEY. THE FOG IS
EXPECTED TO EXPAND EACH NIGHT OVER THE NEXT SEVERAL DAYS,
WITH THE LOWER TREASURE LIKELY TO BE CLOUDY/FOGGY, WHILE THE
UPPER TREASURE HAS FOG AT NIGHT, BUT IMPROVEMENT DURING THE
DAY. THE RIDGE WILL EXPAND OVER WESTERN BC OVER THE NEXT
SEVERAL DAYS ALLOWING FOR COOLER AIR TO MOVE INTO THE AREA FROM
THE NORTH AND EAST WHICH MAY ALTER THE FOG. TEMPERATURE FORECAST
CONFIDENCE IS LOW IN THE VALLEYS, WHERE FOG MAY KEEP HIGH
TEMPERATURES 10-15 DEGREES COOLER THAN THE FORECAST.
LONG TERM...SATURDAY THROUGH WEDNESDAY...DRY AND STABLE
CONDITIONS TO CONTINUE INTO TUESDAY FROM THE HIGH AMPLITUDE
UPPER-LEVEL RIDGE OVER THE WESTERN UNITED STATES. STRONG AND
PERSISTENT INVERSION WILL CONTINUE TO CREATE AREAS OF FOG IN
THE LOWER VALLEYS. BY LATE TUESDAY INTO WEDNESDAY, THE RIDGE
WILL BEGIN TO BREAK DOWN. LONG-RANGE ENSEMBLES AND CLUSTERS
STILL HINT AT AN ACTUAL PATTERN CHANGE (WITH A SHORTWAVE TROUGH
AND PRECIPITATION) LATE NEXT WEEK.
BOI WATCHES/WARNINGS/ADVISORIES
ID...AIR STAGNATION ADVISORY UNTIL 5 AM MST MONDAY
IDZ011>014-016-028-033.
DENSE FOG ADVISORY UNTIL 11 AM MST THURSDAY IDZ012.
OR...AIR STAGNATION ADVISORY UNTIL 5 AM MST /4 AM PST/ MONDAY
ORZ061>064.
DENSE FOG ADVISORY UNTIL 11 AM MST /10 AM PST/ THURSDAY ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...LC
AVIATION.....JY
AIR STAGNATION...KA
SHORT TERM...KA
LONG TERM....CH/LC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page