274
FXUS65 KBOI 080417
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
917 PM MST SAT FEB 7 2026
DISCUSSION
THE LEADING EDGE OF DEEPER MOISTURE IS ADVANCING
THROUGH ERN WASHINGTON AND NE OREGON THIS EVENING. SOME LIGHT
SHOWERS HAVE DEVELOPED ALONG THE SOUTHERN FRINGE AND ARE
ADVANCING ACROSS BAKER COUNTY AND INTO THE W-CENTRAL ID MTNS.
MOUNTAINS STAND THE BEST CHANCE TO SEE MEASURABLE PRECIPITATION
FROM THESE AS THERE IS STILL SOME DRY AIR TO WORK THROUGH AT
LOWER ELEVATIONS. THIS PLUME OF MOISTURE WILL BEND SOUTHWARD ON
SUNDAY, INCREASING THE CHANCE OF SHOWERS ACROSS E-CENTRAL OREGON
AND W-CENTRAL IDAHO. THE EVENING BOISE WX BALLOON SOUNDING
SHOWING THE WET-BULB ZERO HEIGHT AROUND 6800FT MSL, WHICH
MATCHES UP WITH THE FORECAST SNOW LEVELS OF 6-7KFT. SOME HIGH
RESOLUTION MODELS ARE SHOWING A RAIN/SNOW MIX REACHING MTN
VALLEYS AOA 5KFT MSL SUNDAY MORNING AS PRECIPITATION INTENSITY
INCREASES, BUT WOULD EXPECT A RETURN TO RAIN BY AFTERNOON FOR
ANY AREA THAT DOES MIX. AS SUCH SNOW ACCUMULATION WILL BE
GENERALLY LIMITED TO SITES ABOVE 6500 FEET THROUGH SUNDAY. HAVE
MADE SOME MINOR UPDATES TO PRECIPITATION CHANCES OVERNIGHT.
AVIATION
VFR. AREAS OF MVFR/IFR IN LOWERING CEILINGS AND
ISOLATED SHOWERS MOVING INTO SE OREGON AND CENTRAL IDAHO LATE
TONIGHT INTO SUNDAY MORNING, WITH SNOW LEVELS AT 6K-7K FEET MSL.
MOUNTAIN OBSCURATIONS IN PRECIP. SURFACE WINDS: VARIABLE OR SE
UP TO 10 KT, EXCEPT S-SW 5-15 KT IN SE OR AND NEAR ID-NV BORDER.
WINDS ALOFT AT 10KFT MSL: W-SW 10-20 KT.
KBOI...VFR. SLIGHT CHANCE OF MVFR IN LIGHT RAIN AND LOWERING
CEILINGS TOMORROW AFTERNOON. SURFACE WINDS: SE 5-10 KT THROUGH
TOMORROW AFTERNOON.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT...AIR STAGNATION
CONCERNS CONTINUE TODAY WITH LIMITED MIXING AND LIGHT WINDS
THROUGHOUT THE SNAKE RIVER VALLEY. TEMPERATURES NEARLY 20 TO 25
DEGREES ABOVE NORMAL WILL CONTINUE TODAY AND TOMORROW, WITH
HIGHS IN THE VALLEY REACHING NEARLY 60F. SOUTHERLY WINDS WILL
AID IN WARMING TODAY AND TOMORROW, WITH INCREASING CLOUDS LATER
TONIGHT AHEAD OF A PATTERN SHIFT TOMORROW.
THE SHORTWAVE TROUGH PASSAGE TOMORROW IS STILL ON TRACK TO MOVE
THROUGH THE REGION BRINGING VALLEY RAIN, MOUNTAIN SNOW, AND
BREEZY WESTERLY WINDS. PRECIPITATION WILL BEGIN AS RAIN FOR
AREAS BELOW ABOUT 6000-7000 FEET THANKS TO THE EXTENDED WARMING
SEEN IN THE REGION. VALLEY RAIN AND MOUNTAIN SNOW WILL FIRST
MOVE INTO BAKER COUNTY AND EASTERN VALLEY COUNTY EARLY TOMORROW
MORNING, WITH SHADOWING ANTICIPATED IN THE TREASURE VALLEY
THANKS TO THE HIGHER WINDS ALOFT. PRECIPITATION WILL INCREASE
ACROSS THE AREA ALONG THE COLD FRONT AS IT PASSES THROUGH LATE
SUNDAY INTO EARLY MONDAY. PERIODS OF HEAVIER PRECIPITATION WILL
OCCUR LATE SUNDAY, PARTICULARLY IN THE WEST CENTRAL AND BOISE
MOUNTAINS. BY MONDAY EVENING, STORM TOTAL RAINFALL AMOUNTS LOOK
TO BE AROUND 0.25-0.75 INCHES IN THE MOUNTAIN VALLEYS, WITH
ONLY 0.05-0.15 INCHES EXPECTED IN THE LOWER ELEVATION VALLEYS.
SHADOWING EFFECTS WILL POTENTIALLY LOWER THESE RANGES EVEN
FURTHER. SNOWFALL AMOUNTS IN HIGHER ELEVATIONS WILL GENERALLY
RANGE FROM 1-3 INCHES OF SNOW, WITH HIGHER PEAKS SEEING UP TO
4-8 INCHES OF SNOW. RECENT HI-RES MODELS HAVE INCREASED
TEMPERATURES AND DELAYED THE COLD AIR ARRIVAL TOMORROW,
DECREASING CONFIDENCE IN THOSE HIGHER SNOW TOTALS OCCURRING
BELOW 7500 FEET. SNOW LEVELS WILL DROP BEHIND THE FRONT, TO
AROUND 4000-5000 FEET BY EARLY MONDAY MORNING, BUT THIS WILL
PARALLEL THE TIMING OF PRECIPITATION ENDING. THUS, SNOW AMOUNTS
IN LOWER ELEVATIONS IN THE MOUNTAINS WILL BE MINOR, WITH MCCALL,
ID CURRENTLY SEEING A 10% CHANCE OF AT LEAST 3 INCHES OF SNOW
BY MONDAY AFTERNOON. BREEZY TO GUSTY WESTERLY WINDS WILL ALSO
OCCUR WITH THIS SYSTEM TOMORROW AFTERNOON, WITH HIGH ELEVATIONS
SEEING GUSTS FROM 30-40 MPH TOMORROW AFTERNOON AND SUSTAINED
WINDS UP TO 20 MPH.
LONG TERM...TUESDAY THROUGH SATURDAY...AN ACTIVE AND UNSETTLED
PATTERN WILL RETURN FOR THE LONG TERM PERIOD. A WEAK RIDGE WILL
BUILD IN OVER THE AREA FOR TUESDAY, BRINGING GENERALLY DRY
CONDITIONS AND CONTINUING ABOVE NORMAL TEMPERATURES.
A CLOSED LOW OFF THE COAST OF NORTHERN CALIFORNIA WILL MOVE
INLAND ON TUESDAY, BRINGING WARM SOUTHWESTERLY FLOW WITH
PRECIPITATION NEAR THE NEVADA BORDER BY LATE TUESDAY. THIS LOW
WILL PUSH MOISTURE AND WARM AIR INTO OUR AREA ON WEDNESDAY AND
THURSDAY, KEEPING SNOW LEVELS ELEVATED TO THE SOUTH (AROUND
6000-7000 FEET MSL) AND CONTINUING CHANCES FOR PRECIPITATION
FOR MOST OF THE REGION. NORTHERLY FLOW WILL MOVE IN OVER THE
PACIFIC NORTHWEST LATE WEDNESDAY, ALLOWING SOME COLD AIR TO
COMPETE WITH THE WARM AIR ON THURSDAY. THIS WILL LIKELY KEEP
SNOW LEVELS LOWER OVER NORTHERN ZONES, AROUND 4000-5000 FEET
MSL. PRECIPITATION WILL GENERALLY BE LIGHT THANKS TO LIMITED
MOISTURE ALOFT, WITH FORECAST PWAT VALUES IN THE 20TH-40TH
PERCENTILE FROM WEDNESDAY TO THURSDAY. HIGHER ELEVATIONS SOUTH
OF THE SNAKE RIVER VALLEY CAN STILL ANTICIPATE MINOR
ACCUMULATIONS OF SNOW THROUGHOUT THE WEEK.
SOUTHWEST FLOW WILL THEN RETURN BY FRIDAY, WITH EMBEDDED
SHORTWAVES BRINGING SEVERAL PUSHES OF PRECIPITATION THROUGH THE
WEEKEND. SNOW LEVELS WILL LIKELY BE ELEVATED BACK TO THE
5000-6000 FOOT RANGE IN THIS FLOW REGIME, BUT FORECAST
CONFIDENCE IN SNOW AMOUNTS REMAINS LOW DUE TO THE VARIATION IN
STORM TRACK AND THE INFLUENCE OF AN OFFSHORE CLOSED LOW AFTER
THURSDAY. PRECIPITATION CHANCES FOR THE REGION REMAIN IN THE
20-40% RANGE FOR FRIDAY AND SATURDAY.
BOI WATCHES/WARNINGS/ADVISORIES
ID...AIR STAGNATION ADVISORY UNTIL 10 AM MST SUNDAY
IDZ012-014-016-033.
OR...AIR STAGNATION ADVISORY UNTIL 10 AM MST /9 AM PST/ SUNDAY
ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...DG
AVIATION.....JY
SHORT TERM...SA
LONG TERM....SA
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