443
FXUS65 KBOI 120314
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
914 PM MDT THU SEP 11 2025
DISCUSSION
A FEW THUNDERSTORMS ARE STILL ACTIVE LATE THIS
EVENING, BUT RADAR TRENDS SHOW DIMINISHING COVERAGE AND
INTENSITY. FOR THE MOST PART STORMS TODAY BROUGHT HEAVY RAIN,
AND HAIL AND NOT MUCH WIND. SHOWER AND THUNDERSTORM COVERAGE
WILL DECREASE OVERNIGHT, WITH ANY LINGERING CHANCE (15-20%)
ACROSS THE WALLOWAS AND W-CENTRAL IDAHO MTNS. AT THIS TIME ANY
FLOOD/HAIL THREAT IS OVER FOR TONIGHT. COVERAGE WILL INCREASE
AGAIN FRIDAY AFTERNOON ACROSS HIGHER TERRAIN, THOUGH LOWER
ELEVATIONS IN OREGON COULD GET INTO THE MIX AS A FASTER STEERING
FLOW ALOFT WILL PUSH STORMS OFF HIGHER TERRAIN (FROM NORTH TO
SOUTH). CURRENT FORECAST IS ON TRACK FOR TONIGHT WITH MOST AREAS
GOING DRY AND POTENTIAL MTN VALLEY FOG AFTER MIDNIGHT.
AVIATION
SHOWERS AND THUNDERSTORMS WILL TAPER OFF OVERNIGHT.
PATCHY FOG IS EXPECTED IN MOUNTAIN VALLEYS AND HIGHLAND BASINS
TONIGHT, ESPECIALLY KMYL, BUT ALSO MAY DEVELOP NEAR KBKE/KBNO.
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ON FRIDAY OVER
THE HIGHER TERRAIN WITH LOCALIZED MVFR/IFR CONDITIONS AND
MOUNTAIN OBSCURATION. STORMS MAY PRODUCE HEAVY RAIN, SMALL HAIL,
AND GUSTY OUTFLOW WINDS TO 35 KT. SURFACE WINDS: LIGHT AND
VARIABLE OVERNIGHT, BECOMING W-NW 5-15 KT ON FRIDAY. WINDS ALOFT
AT 10KFT MSL: VARIABLE UP TO 10 KT.
KBOI...VFR WITH SCATTERED-BROKEN MID LEVEL CLOUDS. SURFACE
WINDS: SE AROUND 5 KT OVERNIGHT, BECOMING NW 5-10 KT FRIDAY
AFTERNOON.
WEEKEND OUTLOOK...ISOLATED SHOWERS AND THUNDERSTORMS OVER THE
HIGHER TERRAIN ON SATURDAY, BUT OTHERWISE DRIER CONDITIONS WITH
MOSTLY CLEAR SKIES WILL BRIEFLY RETURN. FOG MAY DEVELOP IN
MOUNTAIN VALLEYS EACH NIGHT. SHOWER AND THUNDERSTORM CHANCES
WILL INCREASE ON SUNDAY AS A TROUGH AND COLD FRONT APPROACH.
SURFACE WINDS SW-NW 5-15 KT.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...CONVECTION HAS
ALREADY BEGUN TODAY, WITH SCATTERED LIGHT SHOWERS AND
THUNDERSTORMS EXPECTED TO BECOME NUMEROUS LATER THIS AFTERNOON
TROUGH THIS EVENING. RAIN RATES WILL INCREASE, WITH STRONGER
STORMS CAPABLE OF HEAVY RAINFALL, SMALL HAIL, AND OUTFLOW GUSTS
UP TO 45 MPH. A SLIGHT DEVIATION IN THE LOW HAS SHIFTED OUR AREA
OF BURN SCAR FLASH FLOODING CONCERN FROM OREGON TO CENTRAL
IDAHO. WHILE BURN SCARS IN OREGON WILL STILL RECEIVE SOME RAIN,
THE BULK OF THE MOISTURE SEEMS TO BE PASSING NORTH NOW. IN
IDAHO, THE CHANGE HAS MOVED MOISTURE OVER VERY REACTIVE BURN
SCARS, WITH CONVECTION ALREADY OVER AREAS INCLUDING THE WAPITI
BURN SCAR, SO THE FLASH FLOOD WATCH HAS BEEN MOVED TO CENTRAL
IDAHO.
CHANCES OF PRECIPITATION ACROSS THE AREA OUTSIDE OF AREAS
PREVIOUSLY MENTIONED VARY GREATLY FROM 20% TO 50%, GENERALLY
DECREASING THE CLOSER YOU GET TO THE CENTER OF THE LOW WHICH IS
PROJECTED TO MOVE OVER THE TREASURE VALLEY AND LOWER SNAKE
PLAIN. HEAVY RAIN WILL BE MOSTLY LIMITED TO EASTERN OREGON AND
CENTRAL IDAHO MOUNTAINS. PRECIPITATION BEGINS TO TAPER OFF AFTER
ABOUT 9PM MDT THROUGH MIDNIGHT. OVERNIGHT, LIGHT SHOWERS MAY
CONTINUE ACROSS NORTHERN PORTIONS OF OUR FORECAST AREA, BEFORE
SCATTERED SHOWERS AND ISOLATED STORMS FORM ACROSS BAKER AND
VALLEY COUNTIES, AS WELL AS THE NV BORDER. AS THE LOW EXITS
EASTWARD FRIDAY NIGHT, CONDITIONS WARM AND DRY AS A SHORTWAVE
RIDGE MOVES IN FOR THE WEEKEND, BRINGING TEMPS BACK TO NEAR
NORMAL.
LONG TERM...SUNDAY THROUGH THURSDAY...AN UPPER LEVEL TROUGH
WILL MOVE THROUGH THE PACIFIC NORTHWEST ON SUNDAY. THE BOTTOM
PORTION OF THE TROUGH WILL BRING A POCKET OF MOISTURE AND A
20-50% CHANCE OF SHOWERS/STORMS TO THE AREA, WITH THE GREATEST
CHANCE IN MOUNTAINS. AS IT EXITS TO THE EAST ON MONDAY EVENING,
SHOWERS AND STORMS CONTINUE TO BE POSSIBLE IN CENTRAL ID. THE
RELATED COLD FRONT WILL ALSO BRING BREEZY WINDS AND COOLER
TEMPERATURES ON MONDAY. TUESDAY THROUGH THURSDAY A RIDGE BEGINS
TO AMPLIFY, WARMING TEMPS AND CLEARING SKIES. MODELS DIVERGE
AFTER THURSDAY, BUT DETERMINISTIC MODELS SHOW A DEEP TROUGH
MOVING CLOSE TO THE PACNW AND CANADIAN WEST COASTS. ENSEMBLE
MEANS PROJECT IT STEADILY MOVING INLAND, WHICH WOULD BRING A DAY
OR TWO PRECIPITATION, A COLD FRONT AND BREEZY WINDS. AFTER THE
5-10 DEGREE BELOW NORMAL DAY ON MONDAY, TEMPS WARM BACK UP TO A
FEW DEGREES ABOVE NORMAL THROUGH THE WEEK.
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
DISCUSSION...DG
AVIATION.....ST
SHORT TERM...JM
LONG TERM....JM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page