648
FXUS65 KBOI 181635
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
935 AM MST TUE FEB 18 2025
DISCUSSION
DENSE FOG IS LINGERING IN LOWER ELEVATION VALLEYS
NEAR ONTARIO AND BURNS, OR AND THE LOWER TREASURE VALLEY/WEISER
RIVER VALLEY IN IDAHO THIS MORNING. VISIBILITIES WILL REMAIN
LOW WITH PATCHY ICE ON ROADWAYS FROM FREEZING FOG THROUGH EARLY
AFTERNOON, WITH ABOUT A 20% CHANCE DENSE FOG WILL CONTINUE
THROUGH THE DAY IN THE LOWEST ELEVATIONS NEAR ONTARIO, OR AND
VALE, OR. FOG WILL LIKELY REFORM WITH INCOMING PRECIPITATION
OVERNIGHT. VALLEY RAIN AND MOUNTAIN SNOW WILL MOVE IN TONIGHT
WITH SNOW LEVELS AROUND 3000-4000 FEET, WITH A LOW CHANCE OF
FREEZING RAIN IN SHELTERED VALLEYS NEAR BURNS, OR AND ALONG THE
FOOTHILLS OF THE OWYHEE MOUNTAINS EARLY WEDNESDAY MORNING.
MOUNTAIN VALLEYS (IDAHO CITY & MCCALL) WILL SEE AROUND 3-5" OF
SNOW WITH HIGHER ELEVATION MOUNTAINS SEEING THE POTENTIAL FOR
ACCUMULATIONS AROUND 8-12" BY THURSDAY MORNING. FORECAST HAS
BEEN UPDATED TO ACCOUNT FOR LINGERING FOG THROUGH THIS AFTERNOON
AND THE DENSE FOG ADVISORY HAS BEEN EXTENDED TO 11:00 AM MST.
AVIATION
VFR WITH AREAS OF IFR FOG AND LOW CEILINGS, WITH
IMPROVEMENT TO MVFR AFTER TUE/18Z. FOG MAY BECOME DENSE (IFR) IN
SOME LOCATIONS, SUCH AS KONO AND KEUL, AFTER WED/02Z. SCATTERED MVFR
SNOW SHOWERS AND MOUNTAIN OBSCURATION AROUND KMYL, IMPROVING THIS
AFTERNOON. WIDESPREAD VALLEY RAIN/SNOW AND MOUNTAIN SNOW SHOWERS
CAUSING MVFR AND LOCAL IFR CONDITIONS ON WEDNESDAY. SURFACE WINDS: V
VARIABLE 10 KT OR LESS, EXCEPT W-SW 10-15 KT AT KJER/KTWF/KGNG. WINDS
ALOFT AT 10KFT MSL: W-NW 10-20 KT.
KBOI...LOW VFR CEILINGS. SNOW SHOWERS MOVE IN FROM THE WEST
STARTING AROUND WED/12Z. SURFACE WINDS: VARIABLE 3-6 KT.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
MORNING FOG PERSISTS THROUGH MUCH OF THE SNAKE PLAIN INTO
EASTERN OREGON THIS MORNING AS LOW-LEVEL MOISTURE REMAINS IN
PLACE. MOST PRECIPITATION HAS ENDED ACROSS THE REGION, OUTSIDE
OF A FEW PASSING LIGHT SHOWERS THIS MORNING. A BRIEF RESPITE IN
OUR WET PATTERN WILL OCCUR TODAY, BEFORE THE NEXT PACIFIC SYSTEM
MOVES INTO THE NORTHWEST. PRECIPITATION CHANCES INCREASE ACROSS
EASTERN OREGON EARLY WEDNESDAY MORNING, SPREADING INTO WESTERN
IDAHO BY LATE WEDNESDAY MORNING. SNOW LEVELS INITIALLY WILL BE
NEAR VALLEY FLOORS AS PRECIPITATION COMMENCES, BUT ARE EXPECTED
TO RISE THROUGHOUT THE DAY WEDNESDAY TO AROUND 4000-5000 FEET,
FAVORING A TRANSITION TO RAIN IN THE LOWER ELEVATION VALLEYS.
COLDER AIR BRIEFLY RETURNS THURSDAY MORNING, WITH SNOW LEVELS
FALLING BACK DOWN NEAR VALLEY FLOORS, ALTHOUGH PRECIPITATION
WILL BE MORE ISOLATED AT THIS POINT. SNOW TOTALS IN THE
MOUNTAINS ARE GENERALLY EXPECTED TO RANGE BETWEEN 6 TO 10
INCHES ABOVE 6000 FEET. DRIER AIR WILL QUICKLY MOVE IN LATER
THURSDAY.
LONG TERM...FRIDAY THROUGH TUESDAY...
BROAD RIDGING BUILDS OVER THE NORTHWEST BY THE WEEKEND WITH DRY
CONDITIONS AND A SLIGHT WARMING TREND EXPECTED FRIDAY INTO MUCH
OF SATURDAY. ENSEMBLE GUIDANCE IS SHOWING AN INCREASING SIGNAL
FOR MORE PRECIPITATION LATE SATURDAY INTO SUNDAY, ESPECIALLY IN
THE BOISE MOUNTAINS AND WEST-CENTRAL MOUNTAINS. SNOW LEVELS WILL
GENERALLY BE AT OR ABOVE 6000 FEET FOR THIS EVENT, LIMITING
SNOWFALL TO HIGHER MOUNTAIN TERRAIN. ADDITIONAL EMBEDDED
DISTURBANCES IN WESTERLY FLOW AROUND THE RIDGE CONTINUE INTO
EARLY NEXT WEEK ALONG WITH ASSOCIATED INTERMITTENT INCREASES IN
PRECIPITATION CHANCES. ADDITIONALLY, ENSEMBLE GUIDANCE HAS A
STRONG SIGNAL FOR THE WARMEST TEMPERATURES OF THE YEAR SO FAR
MONDAY AND TUESDAY, WITH MANY LOWER ELEVATION LOCATIONS TOPPING
OUT IN THE 50S.
BOI WATCHES/WARNINGS/ADVISORIES
ID...DENSE FOG ADVISORY UNTIL 11 AM MST THIS MORNING IDZ012-033.
OR...DENSE FOG ADVISORY UNTIL 11 AM MST THIS MORNING ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...SA
AVIATION.....BW
SHORT TERM...JR
LONG TERM....JR
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