942
FXUS65 KBOI 161212
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
612 AM MDT WED SEP 16 2026
UPDATE
UPDATED AVIATION DISCUSSION AND KEY MESSAGES.
KEY MESSAGES
- SLIGHT WARMING AND DRYING TREND WEDNESDAY, WITH LIGHT WINDS.
- A LOW PRESSURE SYSTEM WILL BRING LIGHT PRECIPITATION AND
SCATTERED AFTERNOON THUNDERSTORMS ACROSS THE AREA THURSDAY
AND FRIDAY.
- A FEW STORMS COULD BE STRONG ON THURSDAY WITH HEAVY RAIN,
GUSTY OUTFLOW WINDS, AND SMALL HAIL.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED 311 AM MDT WED SEP 16 2026
LOW PRESSURE IS CURRENTLY DIGGING DOWN TOWARDS NORTHERN
CALIFORNIA, KEEPING ROBUST SOUTHWEST FLOW OVER THE REGION. THIS
LOW WILL CONTINUE TO DEEPEN OVER NORTHERN CALIFORNIA TODAY,
BRINGING SOUTHEASTERLY FLOW ALOFT OVER THE AREA. EASTERLY WINDS
UP TO 10-20 MPH WILL KICK UP OVER THE SOUTHEAST OREGON BY THE
EARLY AFTERNOON. MONSOON MOISTURE WILL BE ADVECTED NORTH THIS
EVENING, WITH A 10-20% CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS OVER SOUTH CENTRAL IDAHO THIS EVENING. AS THE LOW
BEGINS TO SHIFT INTO NORTHERN NEVADA, SHOWERS WILL EXPAND IN
COVERAGE OVER THE TREASURE VALLEY, THE CENTRAL IDAHO MOUNTAINS,
AND SOUTHEAST OREGON ON THURSDAY. MODERATE INSTABILITY (400-800
J/KG OF SURFACE BASED CAPE) AND WIND SHEAR OVER 30 KNOTS WITH
THIS LOW MOVING IN WILL BRING A CHANCE FOR STRONG THUNDERSTORMS
OVER SOUTH CENTRAL IDAHO AND FAR SOUTHEASTERN OREGON. GUSTY
OUTFLOW WINDS UP TO 50 MPH AND SMALL HAIL ARE LIKELY LATE
THURSDAY WITH THE STRONGEST STORMS. ISOLATED SHOWERS AND
THUNDERSTORMS WILL LINGER OVER NORTHEAST OREGON AND CENTRAL
IDAHO ON FRIDAY AND SATURDAY, WITH WARMER AND DRIER CONDITIONS
RETURNING OVER THE REST OF THE REGION. TEMPERATURES WILL COOL
SLIGHTLY ON FRIDAY BEFORE REBOUNDING BACK TO SEASONABLE NORMALS
ON SATURDAY.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED 311 AM MDT WED SEP 16 2026
HIGH PRESSURE WILL REBUILD OVER THE WESTERN US ON SUNDAY,
BRINGING A SLIGHT WARMING AND DRYING TREND TO THE REGION THROUGH
TUESDAY. TEMPERATURES WILL REACH BACK TO NEAR SEASONAL NORMALS,
WITH HIGHS IN THE LOW 80S FOR THE BOISE AREA ON MONDAY. BY LATE
TUESDAY, MODEL SOLUTIONS DIVERGE ON THE TRACK OF A SHORTWAVE
TROUGH TO OUR NORTH. CURRENTLY IT IS FORECAST TO STAY TO OUR
NORTH, BRINGING A 5-10% CHANCE OF SHOWERS OVER HIGH TERRAIN AND
A SLIGHT COOLDOWN ON WEDNESDAY. A FEW SOLUTIONS DEEPEN THE
TROUGH OVER THE REGION, WHICH WOULD BRING AN INCREASED CHANCE OF
PRECIPITATION AND MUCH COOLER TEMPERATURES BY THE MIDDLE OF THE
WEEK.
AVIATION /12Z WEDNESDAY THROUGH THURSDAY/
ISSUED 606 AM MDT WED SEP 16 2026
GENERALLY VFR. BRIEF MVFR CONDITIONS IN A 10-20% CHANCE OF
SHOWERS AND THUNDERSTORMS THIS EVENING NEAR KBKE-KMYL AND KJER-
KTWF. GUSTY OUTFLOW WINDS UP TO 35 KT NEAR STRONG SHOWERS.
SURFACE WINDS: E-NE 5-15 KT WITH GUSTS TO 20 KT IN SE OR. WINDS
ALOFT AT 10KFT MSL: SW 5-15 KT BECOMING SE 15-25 KT BY 21Z/WED.
KBOI...VFR. BRIEF MVFR IN INTERMITTENT HAZE THIS MORNING. SURFACE
WINDS: VARIABLE 5-10 KT THIS MORNING BECOMING NW-N 5-10 KT
DURING THE AFTERNOON.
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
AVIATION.....SA
SHORT TERM...SA
LONG TERM....SA
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