529
FXUS65 KBOI 022023
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
223 PM MDT THU OCT 2 2025
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
ISOLATED RAIN
SHOWERS ACROSS THE HIGH TERRAIN IN IDAHO ARE GRADUALLY MOVING
EAST THIS AFTERNOON AS THE MAIN AREA OF PRECIPITATION THAT WILL
AFFECT US MOVES INTO NEVADA. THE LOW OFF THE COAST OF THE
PACIFIC NORTHWEST WILL CONTINUE TO DIG INTO THE WESTERN US TODAY
AND TOMORROW. A COLD FRONT WILL MOVE INTO THE REGION BRINGING A
BAND OF HEAVY PRECIPITATION TO SOUTHWEST IDAHO THROUGH THE
NIGHT. THE HEAVIEST PRECIPITATION (0.6-1.3 INCHES) LOOKS TO
OCCUR IN A LINE FROM THE WEST CENTRAL MOUNTAINS DOWN THROUGH
IDAHO CITY, BOISE, AND THE OWYHEE MOUNTAINS. THE TREASURE
VALLEY WILL LIKELY SEE RELATIVELY LOWER AMOUNTS (0.40-0.60
INCHES OF RAIN) THANKS TO SOME SHADOWING FROM THE OWYHEE
MOUNTAINS. INTERMITTENT RAIN SHOWERS OUTSIDE OF THE BAND WILL
BRING AT LEAST A FEW HUNDREDTHS TO A WETTING RAIN (0.10 INCHES)
ACROSS THE REGION. RAIN WILL CONTINUE THROUGH FRIDAY AFTERNOON,
WITH SOME WRAPAROUND PRECIPITATION FROM A SURFACE LOW TO THE
SOUTH LIKELY IN SOUTHEAST OREGON. THIS COULD BRING HEAVIER
TOTALS UP TO AN INCH OVER HIGHER TERRAIN IN SOUTHERN
MALHEUR/HARNEY COUNTIES. EMBEDDED CONVECTION IS POSSIBLE THIS
AFTERNOON AND OVERNIGHT WITHIN THE MAIN BAND OF PRECIPITATION
WITH A FEW THUNDERSTORMS PRIMARILY IN THE SOUTHERN BOISE
MOUNTAINS AND NEAR THE NEVADA BORDER. HEAVY RAIN, ESPECIALLY IN
HIGH TERRAIN AND NEAR BURN SCARS, WILL CONTINUE THE RISK OF
FLASH FLOODING THROUGH FRIDAY AFTERNOON. THE WAPITI BURN SCAR
NEAR HIGHWAY 21 WILL CONTINUE TO BE OF PARTICULAR CONCERN, BUT
OTHER BURN SCARS IN THE AREA WILL SEE A RISK OF HIGH
PRECIPITATION TOTALS IN A RELATIVELY SHORT PERIOD OF TIME THAT
COULD LEAD TO DEBRIS FLOWS AND MUDSLIDES.
BREEZY WINDS UP TO 25 MPH WILL ALSO ACCOMPANY HEAVIER PUSHES OF
PRECIPITATION, BUT THE STRONGEST WINDS ARE ANTICIPATED ON
FRIDAY AND SATURDAY AFTERNOON AFTER THE MAIN FRONTAL PASSAGE.
SUSTAINED NORTHWESTERLY WINDS AROUND 20-25 MPH WITH GUSTS UP TO
40 MPH ARE LIKELY IN THE SNAKE RIVER VALLEY TOMORROW AND
SATURDAY AFTERNOON.
THE COOLING TREND WITH TEMPERATURES ABOUT 5-10 DEGREES BELOW
NORMAL WILL CONTINUE THROUGH SATURDAY. DRYING CONDITIONS WILL
OCCUR BY SATURDAY MORNING FOR MOST OF THE REGION, AS THE
LINGERING SHOWERS OVER HIGH TERRAIN IN SOUTHWEST IDAHO MOVE TO
THE EAST WITH THE UPPER LEVEL LOW PUSHING SOUTHEAST.
LONG TERM...SUNDAY THROUGH THURSDAY
FOLLOWING THE RAIN EVENT IN
THE SHORT-TERM, THE IDAHO WEST CENTRAL MOUNTAINS WILL MAINTAIN A 20-
50% CHANCE OF SHOWERS (INCREASING AS YOU MOVE NORTHEAST). THIS WILL
BE THANKS TO THE PASSAGE OF A SHORTWAVE TROUGH WHICH WILL PROPAGATE
ALONG THE BACKSIDE OF THE MAIN TROUGH THAT WILL BE EXITING OUR
REGION. SNOW LEVELS LOWERING TO 6000-7000 FEET ON SUNDAY WILL MEAN
THAT MOUNTAINS SEE PRECIPITATION IN THE FORM OF SNOW/WINTERY MIX.
THIS SHORTWAVE WILL AMPLIFY AND EVENTUALLY CLOSE OFF INTO A LOW OVER
CALIFORNIA. ENSEMBLE CONSENSUS CONTINUES TO SHOW A REX BLOCK
BRIEFLY BUILDING IN WITH SLIGHT RIDGING EXTENDING NORTH OF THE
LOW OVER OUR AREA. THIS WILL ALLOW FOR A GENERAL WARMING TREND
THROUGH THE WEEK AND CHANCES OF PRECIPITATION <10% THROUGH
WEDNESDAY. MODELS GENERALLY AGREE ON A DEEP LOW FORMING OVER THE
GULF OF ALASKA LATE WEDNESDAY INTO FRIDAY AND BREAKING UP THE
REX. HOWEVER, THE EVOLUTION OF THIS LOW IS LEAVING MUCH TO BE
RESOLVED. ENSEMBLES ARE GENERALLY KEEPING IT CLOSER TO THE
SHORE, ALLOWING FOR A SLIGHT CHANCE OF PRECIPITATION ACROSS OUR
AREA COME THURSDAY AFTERNOON. TEMPERATURES WARMING FROM 5-10
DEGREES BELOW NORMAL ON SUNDAY TO NEAR NORMAL BY TUESDAY.
AVIATION
PRECIPITATION BECOMING MORE WIDESPREAD WITH EMBEDDED
THUNDERSTORMS THIS AFTERNOON ACROSS E-OREGON AND SW-IDAHO. MVFR/IFR
AND LOCALIZED LIFR IN HEAVIER PRECIP AND LOW CLOUDS, MOUNTAINS
OBSCURED IN PRECIP. SURFACE WINDS: VARIABLE UP TO 10KT, WITH W-NW
GUSTS OF 20KT THIS AFTERNOON EAST OF KBOI. WINDS ALOFT AT 10KFT MSL:
SW 15-30 KT.
KBOI...RAIN SHOWERS AFTER THU/23Z, CONTINUING THROUGHOUT THE NIGHT.
PERIODS OF MVFR/IFR IN HEAVIER PRECIP THURSDAY NIGHT. SURFACE WINDS:
VARIABLE 4-8KT, BECOMING NW 8-12KT WITH GUSTS TO 20 KT AFTER
FRI/00Z.
WEEKEND OUTLOOK: SHOWERS CONTINUING IN SW-IDAHO THROUGH SATURDAY
MORNING. BEFORE ISOLATED SHOWERS ACROSS THE CENTRAL IDAHO MOUNTAINS
SATURDAY AND SUNDAY AFTERNOONS. SNOW LEVELS LOWERING TO 6-7KFT BY
SUNDAY AFTERNOON. SURFACE WINDS: N-NW 10-15 KT GUSTING TO 20-30 KT
SATURDAY WITH LOCALIZED GUSTS TO 40 KT IN THE SNAKE PLANE. BECOMING
N-NW 5-15 KT BY SUNDAY AFTERNOON.
BOI WATCHES/WARNINGS/ADVISORIES
ID...FLASH FLOOD WATCH FROM 6 PM MDT THIS EVENING THROUGH FRIDAY
AFTERNOON IDZ011-013.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...SA
LONG TERM....NF
AVIATION.....NF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page