984
FXUS65 KBOI 132003
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
203 PM MDT MON APR 13 2026
KEY MESSAGES
- WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW ABOVE 4500 FEET ON MONDAY.
- SNOW LEVELS WILL DROP TO NEAR VALLEY FLOORS THURSDAY MORNING
WITH COLD FRONTAL PASSAGE FOR WIDESPREAD LOWER ELEVATION SNOW
LIKELY.
- NEAR TO BELOW FREEZING MORNING TEMPERATURES LIKELY THURSDAY
THROUGH SATURDAY ACROSS THE ENTIRE AREA.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
THE ACTIVE PATTERN REMAINS IN PLACE ACROSS SOUTHEAST OREGON AND
SOUTHWEST IDAHO. RAIN AND SNOW SHOWERS CONTINUE THROUGH THE
REMAINDER OF THE AFTERNOON, TAPERING BY MID EVENING. SIGNIFICANT
SNOW HAS FALLEN ABOVE 6000 FEET TODAY WITH REPORTS OF 14 TO 18
INCHES OF SNOWFALL. AS OF 1 PM MDT TODAY, 2.40 INCHES OF
RAINFALL HAS BEEN RECORDED FOR THE MONTH OF APRIL 2026 AT BOISE.
THIS CURRENTLY RANKS AS THE 9TH WETTEST APRIL ON RECORD FOR THE
BOISE AREA, WITH 17 DAYS REMAINING IN THE MONTH.
FOR TONIGHT AND TUESDAY, A BRIEF PERIOD OF WEAK RIDGING WILL
MOVE THROUGH THE REGION, PROVIDING A SHORT LULL IN THE
WIDESPREAD PRECIPITATION SEEN EARLIER THIS WEEK. LIGHT WINDS,
CLEARING SKIES, AND SIGNIFICANT SURFACE MOISTURE WILL PROMOTE
THE DEVELOPMENT OF PATCHY FOG TUESDAY MORNING, ESPECIALLY ACROSS
THE LONG VALLEY AND TREASURE VALLEY. THE BREAK IS SHORT LIVED
AS A STRONG UPPER LEVEL LOW CURRENTLY OVER ALASKA BEGINS TO DIG
SOUTH ALONG THE PACIFIC COAST LATE TUESDAY AFTERNOON AND
EVENING. CLOUDS WILL INCREASE FROM THE WEST AS MOISTURE BEGINS
TO ADVECT INTO THE REGION AHEAD OF THE NEXT SYSTEM. LIGHT RAIN
SHOWERS WILL DEVELOP OVER THE MOUNTAINS OF SOUTHEAST OREGON LATE
TUESDAY, SPREADING INTO SOUTHWEST IDAHO OVERNIGHT.
THE MAIN WEATHER EVENT ARRIVES WEDNESDAY AS THE COLD FRONT
APPROACHES. STRONG SOUTHWESTERLY FLOW AHEAD OF THE FRONT WILL
RESULT IN BREEZY CONDITIONS WEDNESDAY AFTERNOON, WITH GUSTS OF
25 TO 35 MPH POSSIBLE ACROSS THE HIGHER TERRAIN AND OPEN VALLEYS
OF SOUTHEAST OREGON. WIDESPREAD RAIN IS EXPECTED FOR THE
VALLEYS THROUGH WEDNESDAY EVENING, WITH SNOW LEVELS INITIALLY
REMAINING AROUND 5000 TO 6000 FEET MSL.
THE COLD FRONTAL PASSAGE IS TIMED FOR LATE WEDNESDAY NIGHT INTO
EARLY THURSDAY MORNING. THIS FRONT WILL BRING A SHARP
TRANSITION IN THE WEATHER. WINDS WILL SHIFT TO THE NORTHWEST AND
REMAIN GUSTY. MORE IMPORTANTLY, A MUCH COLDER AIR MASS WILL
POUR INTO THE REGION, CAUSING SNOW LEVELS TO PLUMMET TOWARD
VALLEY FLOORS BY SUNRISE THURSDAY. WHILE THE BULK OF THE
MOISTURE WILL BE MOVING EAST, WRAP AROUND MOISTURE AND UNSTABLE
NORTHWESTERLY FLOW WILL SUPPORT A MIX OF RAIN AND SNOW FOR THE
TREASURE AND MAGIC VALLEYS, WITH LIGHT SNOW ACCUMULATIONS
POSSIBLE ON GRASSY SURFACES AND HIGHER VALLEY BENCHES. IN THE
MOUNTAINS, LOWER VALLEYS WILL SEE A FEW INCHES OF SNOW BUT AREAS
ABOVE 5500 FEET COULD SEE SEVERAL INCHES OF NEW SNOW THURSDAY
MORNING, WHICH MAY IMPACT TRAVEL OVER MOUNTAIN PASSES.
LONG TERM /THURSDAY THROUGH MONDAY/
FOLLOWING A STRONG COLD FRONT, TEMPERATURES ON THURSDAY COOL
DOWN TO 5-10 DEGREES BELOW NORMAL. NOT EXCEPTIONALLY COLD
CLIMATOLOGICALLY, BUT FOLLOWING A LONG WARM SPELL IT WILL FEEL
LIKE A SUDDEN BURST OF WINTER FOR LOWER ELEVATIONS. IT'S ENOUGH
FOR MOST OF THE SNAKE PLAIN TO SEE SUB-FREEZING MORNING LOW
TEMPERATURES. AGAIN, THIS ISN'T CLIMATOLOGICALLY EXCEPTIONAL,
HOWEVER, A GREEN UP IN THE PAST TWO WEEKS HAS SEEN MANY PLANTS
BEGIN TO BLOOM OR SPROUT. THE FREEZING MORNING TEMPERATURES
THREATEN THIS NEW GROWTH, ESPECIALLY FOR GARDENS AND CROPS. FOR
THOSE WHO STARTED THEIR GARDEN EARLY, IT MAY BE WISE TO CONSIDER
COVERING UP PLANTS OR BRINGING THEM INSIDE. PERSONALLY, I'M
GOING TO BE USING THE TIME TO CLEAN UP AFTER LATE WINTER AND
EARLY SPRING BUG HATCHES.
ASIDE FROM THE COLD MORNING TEMPERATURES, AS SNOW TAPERS OFF
THURSDAY EVENING HIGH PRESSURE BUILDS AND WE HEAD INTO A WARMING
AND DRYING TREND. THE DRYING TREND ALLOWS MORNING LOWS TO STAY
NEAR FREEZING THROUGH SATURDAY, BUT AFTERNOON HIGH TEMPERATURES
WILL CLIMB BACK UP TO NEAR NORMAL. GUSTY WINDS UP TO 35 MPH ON
THURSDAY WEAKEN EACH AFTERNOON, TO 30 MPH FRIDAY, AND 20 MPH
SATURDAY. SUNDAY, TEMPS ARE ABOUT 5 DEGREES ABOVE NORMAL. SUNDAY
NIGHT AND NEXT MONDAY MODELS SHOW ANOTHER STRONG LOW DIVING
SOUTH ALONG THE WEST COAST, AND ISOLATING ITSELF FROM THE JET
STREAM. THIS WILL MARK THE ONSET OF ANOTHER COOL AND WET PERIOD.
AVIATION /18Z MONDAY THROUGH TUESDAY/
ISSUED 1152 AM MDT MON APR 13 2026
WIDESPREAD STEADY RAIN CAUSING MVFR/IFR CONDITIONS THROUGHOUT
THE AREA WILL MOVE EAST, TRANSITIONING TO SCATTERED SHOWERS
ENDING THIS EVENING. STRONG SHOWERS COULD PRODUCE GUSTY WINDS
AND GRAUPEL. SNOW LEVELS ARE RIGHT AROUND 6KFT MSL. TONIGHT,
AFTER PRECIP ENDS FOG/LOW STRATUS BECOME POSSIBLE IN THE SNAKE
PLAIN AND MTN VALLEYS. SURFACE WINDS: W-NW 5-15 KT WITH GUSTS
TO 20-25 KT, BECOMING VARIABLE UP TO 10 KT OVERNIGHT. WINDS
ALOFT AT 10KFT MSL: W-NW 10-20KT.
KBOI...STEADY RAIN IS TRANSITIONING TO SCATTERED SHOWERS THIS
AFTERNOON. RAIN DISSIPATES OVERNIGHT, WITH A SLIGHT CHANCE OF
FOG/LOW STRATUS MON NIGHT/TUE AM. SURFACE WINDS: NW 5-10KT.
BOI WATCHES/WARNINGS/ADVISORIES
ID...NONE.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...JDS
LONG TERM....JM
AVIATION.....JM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page