267
FXUS65 KBOI 141608
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1008 AM MDT SUN SEP 14 2025
DISCUSSION
SHOWERS AND THUNDERSTORMS ARE ONGOING OVER EASTERN
OREGON AND THE OR/ID BORDER THIS MORNING, WITH SPATIAL COVERAGE
EXPECTED TO INCREASE OVER THE NEXT FEW HOURS. STORM MOTION WILL
CONTINUE TO BE NE AROUND 30 KTS, AS IS ALREADY SEEN WITH
CURRENT THUNDERSTORMS. THE WELL-DEFINED NEGATIVELY TILTED TROUGH
WILL CONTINUE THROUGH THE REGION, WITH AN ASSOCIATED COLD FRONT
ALREADY MOVING THROUGH EASTERN OREGON. RECENT CAMS (HRRR, FV3,
NAMNST) HAVE SOME MORE ISOLATED TO SCATTERED THUNDERSTORMS
IMPACTING THE UPPER TREASURE VALLEY AREA THIS AFTERNOON AND
EARLY EVENING. CONVECTIVE PARAMETERS STILL APPEAR FAVORABLE FOR
GUSTY OUTFLOW WINDS UP TO 50 MPH, SMALL HAIL, AND HEAVY
RAINFALL. STORM TRACKS AND INTENSITY WILL NEED TO BE HEAVILY
MONITORED NEAR BURN SCARS. NO CHANGES TO THE FORECAST AT THIS
TIME.
AVIATION
SCATTERED SHOWERS AND THUNDERSTORMS MOVING W TO E
THROUGH THIS EVENING. STORMS CAPABLE OF MVFR/IFR CONDITIONS,
MOUNTAIN OBSCURATION, GUSTY OUTFLOW WINDS UP TO 45 KT, SMALL HAIL,
AND HEAVY RAIN. HIGHEST STORM CHANCES ALONG/N OF I-84. OTHERWISE,
VFR. SMOKE LAYERS ALOFT, IMPROVING LATER TODAY. SURFACE WINDS SE-SW
5-15 KT IN THE MORNING, BECOMING W-NW 10-20 KT IN THE AFTERNOON AND
EVENING. WINDS ALOFT AT 10KFT MSL: SW 10-25 KT.
KBOI...MAINLY VFR WITH SMOKE LAYERS ALOFT. 50% CHANCE OF A
THUNDERSTORM IMPACTING THE TERMINAL BETWEEN 20-01 UTC. BRIEF
GUSTY WINDS OVER 40 KT, BLOWING DUST, HEAVY RAIN AND SMALL HAIL
POSSIBLE. SURFACE WINDS: SE 5-15 KT OVERNIGHT, BECOMING NW 10-15
KT GUSTS TO 20-25 KT AFTER SUN/17Z WITH COLD FRONT. HIGHER
THUNDERSTORM GUSTS.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH TUESDAY NIGHT...CLOUDS HAVE
INCREASED THIS MORNING AHEAD OF A NEGATIVELY TILTED TROUGH
MOVING ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST. SHOWERS
AND THUNDERSTORMS ALONG THE COLD FRONT WILL REACH SOUTHEAST
OREGON JUST BEFORE SUNRISE AROUND 6 AM MDT, THEN PROGRESS EAST-
NORTHEAST THROUGH THE DAY—ARRIVING AT THE IDAHO–OREGON BORDER
AROUND 1 PM MDT, THE TREASURE VALLEY AROUND 2 PM MDT, AND
MCCALL/BANNER SUMMIT NEAR 3 PM MDT. ADDITIONAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED BEHIND THE FRONT ACROSS BAKER COUNTY
AND THE WEST-CENTRAL IDAHO MOUNTAINS AS THE LOW CENTER TRACKS
JUST NORTH OF THE AREA. RECENT CAM GUIDANCE HAS SHIFTED THE BEST
THUNDERSTORM POTENTIAL FARTHER NORTH, GENERALLY ALONG AND NORTH
OF A ROME–BOISE–BANNER SUMMIT LINE.
CONVECTIVE PARAMETERS REMAIN FAVORABLE FOR A FEW STRONGER
STORMS, WITH BULK SHEAR NEAR 30 KTS AND MUCAPE VALUES AROUND 500
J/KG. HAZARDS INCLUDE GUSTY OUTFLOW WINDS UP TO 50 MPH, SMALL
HAIL, AND HEAVY RAINFALL. PRECIPITABLE WATER VALUES ARE NEAR THE
85TH PERCENTILE, AND HOURLY RAINFALL RATES COULD REACH 0.5
INCHES WITH THE STRONGEST STORMS, POSING A LOCALIZED FLASH FLOOD
RISK NEAR BURN SCARS.
AN UPPER-LEVEL RIDGE BUILDS INTO THE REGION MONDAY, THOUGH
TEMPERATURES WILL REMAIN ABOUT 10 DEGREES BELOW NORMAL.
TEMPERATURES MODERATE BACK TO NEAR NORMAL TUESDAY AS THE RIDGE
AXIS SHIFTS EAST.
LONG TERM...WEDNESDAY THROUGH SUNDAY...THE UPPER-LEVEL RIDGE
WILL HOLD OVER THE AREA THROUGH AT LEAST THURSDAY, KEEPING
MOSTLY SUNNY SKIES AND NEAR-NORMAL TEMPERATURES IN PLACE. HIGHS
WILL WARM TO AROUND 5 DEGREES ABOVE NORMAL BY THURSDAY. BY
FRIDAY, A MORE COMPLEX SYNOPTIC PATTERN DEVELOPS WITH A TROUGH
AXIS SETTING UP ALONG THE WEST COAST AND POSSIBLY TWO CLOSED
LOWS ON EITHER SIDE OF OUR AREA. MODEL SOLUTIONS VARY ON THEIR
EXACT PLACEMENT, BUT THE GENERAL OUTCOME POINTS TO COOLER
CONDITIONS WITH MORE CLOUD COVER AND A SLIGHT CHANCE OF SHOWERS
FRIDAY INTO SATURDAY. TEMPERATURES WILL TREND BACK TOWARD NORMAL
BY LATE WEEK AND INTO THE WEEKEND.
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...CH
AVIATION.....JR
SHORT TERM...JDS
LONG TERM....JDS
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