192
FXUS65 KBOI 200347
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
847 PM MST TUE NOV 19 2024
DISCUSSION
A PROMINENT ATMOSPHERIC RIVER IS PUSHING SOME MID
TO HIGH LEVEL CLOUDS INTO THE REGION THIS EVENING, WITH
INCOMING SNOW ANTICIPATED LATER. BREEZY SOUTHEAST WINDS WILL
CONTINUE TO INCREASE THROUGHOUT THE NIGHT, WITH SNOWY CONDITIONS
BEGINNING IN HIGH TERRAIN IN SOUTHEAST OREGON BY MIDNIGHT.
FORECAST STILL LOOKS TO BE ON TRACK WITH LIGHT SNOW SPREADING TO
MOST OF THE MOUNTAINS AND THE TREASURE VALLEY BY THE MORNING.
THE SNAKE RIVER VALLEY WILL LIKELY BE SHADOWED FROM THE BULK OF
THE PRECIPITATION IN THE MORNING THANKS TO SOUTHWEST FLOW AND
STRONG SOUTHEAST WINDS. SNOW WILL SHIFT TO RAIN FOR ELEVATIONS
BELOW ABOUT 4000-5000 FEET BY THE AFTERNOON, AND WARM AIR WILL
RISE SNOW LEVELS TO 6500-7500 FEET BY THURSDAY MORNING. UPDATED
WIND FORECAST TO ACCOUNT FOR INCREASED RIDGETOP WIND SPEEDS FOR
TOMORROW AFTERNOON.
AVIATION
VFR MOST LOCATIONS THROUGH 20/08Z, BECOMING MVFR
WITH LOCALIZED IFR IN PRECIPITATION AFTER. LIGHT SNOW WILL
BEGIN IN SE OR TONIGHT, SPREADING INTO THE SW ID MOUNTAINS BY
EARLY MORNING. WIDESPREAD MVFR/IFR CONDITIONS, AND TERRAIN
OBSCURATION WITH INTERMITTENT PRECIPITATION THROUGH THURSDAY.
LOW LEVEL WIND SHEAR LIKELY FOR MANY SITES BEGINNING
20/06-20/18Z. SURFACE WINDS: SE 15-25 KT WITH GUSTS 30-40 KT.
WINDS ALOFT: SW 40-50 KT WITH AREAS OF 50-60 KT IN SE OR.
KBOI
VFR, THEN PERIODS OF LIGHT SNOW BRINGING MVFR CEILINGS FROM
20/08Z-20/16Z, THEN SHIFTING TO RAIN SHOWERS THROUGH THE DAY.
SURFACE WINDS: SE 15-25 KT WITH GUSTS TO 30 KT. LOW LEVEL WIND
SHEAR LIKELY OVERNIGHT WITH INCREASING SE WINDS.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...A SHORT-WAVE
RIDGE BUILDS IN BRIEFLY TONIGHT, CUTTING OFF ISOLATED SNOW IN
THE NORTH BEFORE A STRONG STORM IN THE PACIFIC MOVES IN. WINDS
CONTINUE TO INCREASE TONIGHT THROUGH WEDNESDAY AFTERNOON AHEAD
OF THE STORM. IN SE AND E OREGON WIND GUSTS OF UP TO 50 MPH ARE
POSSIBLE, WITH GENERAL GUSTS OF 35-45 MPH. THIS HAS PROMPTED THE
ISSUANCE OF TWO WIND ADVISORIES, ONE FOR HARNEY COUNTY, AND ONE
OF BAKER COUNTY AND THE LOWER TREASURE VALLEY IN OREGON. WHILE
WINDS WILL STAY BREEZY THROUGH THE SHORT TERM, THE ADVISORY IS
SET TO END WEDNESDAY AFTERNOON AS THE WINDS WEAKEN JUST BELOW
CRITERIA.
MOISTURE STREAMS INTO THE AREA BEGINNING WEDNESDAY MORNING.
PRECIPITATION CHANCES NORTH OF A LINE FROM BURNS-BOISE-FAIRFIELD
REMAIN 80-100% EVERY 6 HOURS THROUGH THE SHORT TERM.
PRECIPITATION BEGINS AS SNOW WEDNESDAY MORNING, BUT SOUTHWEST
FLOW ALOFT AND BUILDING HEIGHTS WILL SUPPORT TEMPERATURES RISING
THROUGH THE WEEK. A DUSTING OF SNOW IS LIKELY WEDNESDAY MORNING
BEFORE THE BULK OF THE MOISTURE MOVES IN AND RAIN IS FAVORED
BELOW 5000 FT MSL. ENOUGH SNOW WILL FALL WEDNESDAY THROUGH
THURSDAY MORNING FOR MOUNTAIN PASSES IN CENTRAL IDAHO TO SEE 4
TO 7 INCHES OF ACCUMULATION, ENOUGH FOR A WINTER WEATHER
ADVISORY. THANKS TO THE CONTINUOUS WARMING, IMPACTS MAY BE
SHORTLIVED AS TEMPS ALONG MOUNTAIN PASSES ARE SET TO WARM TO
NEAR/JUST ABOVE FREEZING ON THURSDAY. IN MOUNTAIN VALLEYS, SUCH
AS NEAR CASCADE AND MCCALL, 1-3 INCHES OF SNOW ARE FORECAST, AND
TEMPS WARM ABOVE FREEZING WEDNESDAY AFTERNOON, AND HOVER NEAR
FREEZING THURSDAY MORNING. LIQUID EQUIVALENT AND RAINFALL TOTALS
THROUGH THE SHORT TERM ARE UPWARDS OF AN INCH NORTH OF THE
BURNS-BOISE-FAIRFIELD LINE, EVEN UP TO 2 INCHES ALONG THE
HIGHEST SUMMITS AS OROGRAPHIC EFFECT WILL PLAY A SIGNIFICANT
ROLE IN PRECIPITATION PRODUCTION.
LONG TERM...FRIDAY THROUGH TUESDAY...ACTIVE WEATHER PATTERN TO
CONTINUE INTO NEXT WEEK. THE DEEP TROUGH AND ASSOCIATED MOISTURE
PLUME WILL BE AIMED AT EASTERN OREGON AND SOUTHWEST IDAHO FRIDAY
INTO SATURDAY AS A COLD FRONT WORKS THROUGH THE REGION. THIS WILL
ALLOW FOR WIDESPREAD PRECIPITATION, WITH SNOW LEVELS ABOVE 7000 FEET
FRIDAY, DROPPING TO AROUND 4500 FEET ON SATURDAY. GOOD AGREEMENT
THAT THE UNSETTLED WEATHER WILL CONTINUE INTO MID-WEEK, WITH A
SYSTEM ON SUNDAY/MONDAY, AND INSTABILITY SHOWERS ON TUESDAY.
TEMPERATURES WILL COOL TO NEAR NORMAL BY EARLY NEXT WEEK.
BOI WATCHES/WARNINGS/ADVISORIES
ID...WINTER WEATHER ADVISORY FROM 5 AM WEDNESDAY TO 5 AM MST
THURSDAY IDZ011-013.
OR...WIND ADVISORY UNTIL 11 AM MST /10 AM PST/ WEDNESDAY
ORZ061-062-064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.TWITTER.COM/NWSBOISE
DISCUSSION...SA
AVIATION.....SA
SHORT TERM...JM
LONG TERM....MC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page