895
FXUS65 KBOI 142149
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
249 PM MST WED JAN 14 2026
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 INVERSIONS WILL CONTINUE TO BRING FOG CHANCES,
ESPECIALLY IN LOWER VALLEYS. BY LATE TUESDAY INTO WEDNESDAY, THE
RIDGE BEGINS TO BREAK DOWN IN AMPLITUDENESS, HOWEVER LONG-RANGE
ENSEMBLES AND CLUSTERS STILL HINT AT AN ACTUAL PATTERN CHANGE
(WITH A SHORTWAVE TROUGH AND PRECIPITATION) LATE NEXT WEEK.
AVIATION
MVFR-LIFR CONDITIONS AND MOUNTAIN OBSCURATION IN
AREAS OF FOG/LOW STRATUS OVERNIGHT WEDNESDAY INTO THURSDAY,
MAINLY IN SHELTERED MOUNTAIN-VALLEYS AND LOWER BASINS.
PERSISTENT FZFG IS OF PARTICULAR NOTE IN THE LOWER TREASURE
VALLEY AND IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON.
SURFACE WINDS: VARIABLE UP TO 10 KT. WINDS ALOFT AT 10KFT MSL:
NW 5-20 KT.
KBOI...VFR. MVFR-IFR CONDITIONS ARE POSSIBLE (30% CHANCE) AGAIN
WEDNESDAY NIGHT INTO THURSDAY MORNING FROM FOG AND LOW CEILINGS,
PARTICULARLY AFTER 03Z/THU. CHANCES DIMINISH AFTER 18Z/THU.
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.
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
SHORT TERM...KA
LONG TERM....CH
AVIATION.....CH
AIR STAGNATION...KA
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