680
FXUS65 KBOI 051624
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
924 AM MST THU FEB 5 2026
DISCUSSION
AREAS OF FOG HAVE BEEN OBSERVED THIS MORNING,
GENERALLY IN LOWER BASINS AND MOUNTAIN VALLEYS. HAVE UPDATED
THE FORECAST TO INCLUDE A BROADER COVERAGE OF THIS FOG, HOWEVER
THE EXPECTATION IS FOR IT TO BURN OFF THROUGH THE MORNING AS
INSOLATION (SURFACE HEATING) INCREASES. OTHERWISE, ANOTHER MILD
DAY IS ON TAP TODAY WITH GENERALLY CLEAR SKIES ASIDE FROM A FEW
HIGH CLOUDS. WITH LIGHT WINDS AND THE MORNING SOUNDING SHOWING A
STOUT INVERSION, STAGNANT CONDITIONS WILL PERSIST; THIS WILL
RESULT IN POLLUTANTS GETTING TRAPPED IN VALLEYS AND MAINTAIN THE
RISK FOR MORNING HAZE AND FOG OVERNIGHT TONIGHT.
AVIATION
LOCAL IFR IN FOG ALONG THE SNAKE RIVER (KEUL-KONO) AND
IN MTN VALLEYS WILL BURN OFF BY LATE MORNING. OTHERWISE VFR, THOUGH
HAZE WILL CONTINUE TO DIMINISH VISIBILITY IN VALLEYS. LOCAL IFR
CONDITIONS WILL RETURN TONIGHT WITH REDEVELOPMENT OF FOG. SURFACE
WINDS: UP TO 10 KT, EXCEPT E-NE 10-20 KT IN THE CENTRAL SNAKE PLAIN
(KJER-KGNG). WINDS ALOFT AT 10KFT MSL: VARIABLE 5-15 KT.
KBOI...VFR IN HAZE. LIGHT SURFACE WINDS.
WEEKEND OUTLOOK...MORNING IFR IN FOG ACROSS PORTIONS OF LOWER SNAKE
PLAIN AND IN MTN VALLEYS SATURDAY. OTHERWISE VFR THROUGH SATURDAY
NIGHT. LOWERING CEILINGS AND A CHANCE OF RAIN AND SNOW INCREASING ON
SUNDAY. VALLEYS REMAIN VFR ON SUNDAY, WITH IFR DEVELOPING IN THE
MTNS. SNOW LEVELS 6-7KFT MSL.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...UPPER LEVEL RIDGE
AND THE INVERSION IN THE VALLEYS WILL BE AT MAXIMUM STRENGTH
TODAY OVER OUR CWA. NEAR-RECORD HIGH TEMPS ARE EXPECTED AGAIN
TODAY AND FRIDAY EVEN IN THE INVERSION AREAS. THE MAIN RIDGE
WILL SHIFT EAST OF OUR CWA TONIGHT THROUGH SUNDAY. A PACIFIC
UPPER LOW MOVING INLAND ACROSS THE SWRN US WILL SLIGHTLY WEAKEN
THE RIDGE AS FAR NORTH AS OUR AREA FRIDAY NIGHT AND SATURDAY,
BUT IT WILL REBUILD LATER SATURDAY IN OREGON, AND SATURDAY
NIGHT IN IDAHO. HIGHER ELEVATIONS WILL COOL SLIGHTLY SATURDAY
BUT THE VALLEYS WILL FEEL NOTHING FROM THE PASSING LOW.
LONG TERM...SUNDAY THROUGH THURSDAY...THE UPPER RIDGE WILL
FLATTEN SUNDAY AS A NORTH PACIFIC COLD FRONT AND SUPPORTING
UPPER TROUGH MOVE ONTO THE NORTHWEST COAST. THE FRONT WILL REACH
OUR CWA LATE SUNDAY NIGHT AND MONDAY MORNING WITH RAIN AND SNOW
SHOWERS, GUSTY NORTHWEST WINDS, AND MUCH COOLER AIR ESPECIALLY
ALOFT. THE COOLING WILL WEAKEN THE INVERSION IN THE UNDERLYING
VALLEYS. WINDS ALONG AND BEHIND THE COLD FRONT SHOULD EASILY BE
ABLE TO CLEAR THE STAGNANT AIR FROM THE VALLEYS. TUESDAY THROUGH
THURSDAY WILL FINALLY COOL TO SEASONABLE TEMPERATURES. THERE
WILL STILL BE ENOUGH MOISTURE FOR A 30 TO 50 PERCENT CHANCE OF
SNOW SHOWERS IN THE MOUNTAINS, BUT OVERALL THOSE DAYS LOOK DRIER
THAN MONDAY.
BOI WATCHES/WARNINGS/ADVISORIES
ID...AIR STAGNATION ADVISORY UNTIL 5 AM MST MONDAY
IDZ012-014-016-033.
OR...AIR STAGNATION ADVISORY UNTIL 5 AM MST /4 AM PST/ MONDAY
ORZ062>064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...NF
AVIATION.....DG
SHORT TERM...LC
LONG TERM....LC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page