275
FXUS65 KBOI 270015
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
615 PM MDT FRI JUN 26 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- SCATTERED THUNDERSTORMS THIS AFTERNOON INTO EARLY SATURDAY
COULD PRODUCE STRONG OUTFLOW WINDS, SMALL HAIL AND BRIEF HEAVY
RAIN.
- TEMPERATURES AROUND 15 TO 20 DEGREES BELOW NORMAL SATURDAY AND
SUNDAY.
- SIGNIFICANT PRECIPITATION AND LIGHT SNOW ABOVE 7000 FEET POSSIBLE
SATURDAY THROUGH SUNDAY.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED 213 PM MDT FRI JUN 26 2026
THE MAIN FOCUS THROUGH LATE THIS EVENING WILL BE THE POTENTIAL
FOR STRONG THUNDERSTORMS DEVELOPING ACROSS THE REGION. CLEARING
OF SKIES ACROSS SOUTHEAST OREGON HAS ALLOWED FOR SURFACE HEATING
FOR MODEST INSTABILITY (SBCAPE OF 50 TO 200 J/KG) AND THE
INITIATION OF THUNDERSTORMS ACROSS SOUTHEAST OREGON. INITIAL
CONVECTIVE ACTIVITY WILL BE CAPABLE OF PRODUCING STRONG, ERRATIC
OUTFLOW WIND GUSTS UP TO 50 MPH DUE TO RELATIVELY DRY LOW-
LEVELS. HOWEVER, AS ATMOSPHERIC MOISTURE STEADILY INCREASES
OVERNIGHT, THIS SEVERE WIND THREAT WILL GRADUALLY DIMINISH AND
STORMS WILL PRODUCE BRIEF HEAVY RAIN AND SMALL HAIL.
THUNDERSTORM ACTIVITY IS EXPECTED TO PERSIST THROUGH THE
OVERNIGHT HOURS AND CONTINUE THROUGH SATURDAY ACROSS MUCH OF THE
FORECAST AREA. WITH THE ADDED MOISTURE, STORMS WILL BECOME
CAPABLE OF PRODUCING HEAVY RAINFALL AND SMALL HAIL. THE BEST
DYNAMICS, MOISTURE POOLING, AND OVERALL CHANCE FOR STORMS AND
HEAVIER RAINFALL AMOUNTS WILL FOCUS ACROSS SOUTHWEST IDAHO. THE
POTENTIAL FOR HEAVIER RAINFALL ACROSS THE CENTRAL IDAHO
MOUNTAINS SATURDAY INCREASES THE POTENTIAL FOR ROCK SLIDES AND
LOCALIZED FLOODING ESPECIALLY NEAR LEGACY BURN SCARS, LIKE THE
WAPITI FIRE BURN SCAR AND WILL NEED TO BE MONITORED.
CONVECTIVE ACTIVITY AND OVERALL PRECIPITATION CHANCES WILL
BEGIN TO TAPER OFF EARLY SUNDAY AS THE SYSTEM STARTS TO EXIT THE
REGION. SHOWERS AND THUNDERSTORMS WILL PERSIST ON THE BACKSIDE
OF THE LOW ACROSS THE CENTRAL IDAHO MOUNTAINS AS WELL AS BAKER
COUNTY AND ALONG THE IDAHO/NEVADA BORDER.
PRECIPITATION AMOUNTS OF 1 TO 1.25 INCHES ARE POSSIBLE OVER THE
CENTRAL IDAHO MOUNTAINS THROUGH SUNDAY. LESSER AMOUNTS ARE
EXPECTED IN EASTERN OREGON, WHERE 0.25 TO 0.75 INCHES IS
FORECAST, WHILE THE SNAKE RIVER PLAIN WILL GENERALLY SEE BETWEEN
0.25 AND 0.50 INCHES. ABOVE 6500 FEET COULD SEE UP TO 3 INCHES
OF WET SNOW SATURDAY NIGHT INTO SUNDAY. TEMPERATURES WILL
PLUMMET TO AROUND 20 DEGREES BELOW NORMAL SATURDAY AND SUNDAY.
SEVERAL LOCATIONS ARE FORECAST TO APPROACH RECORD LOW MAXIMUM
TEMPERATURES FOR THE DAY BOTH DAYS. NEAR RECORD LOW TEMPERATURES
ARE ALSO POSSIBLE ACROSS SOUTHEAST OREGON SUNDAY MORNING.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED 213 PM MDT FRI JUN 26 2026
GRADUAL WARMING AND DRYING MONDAY AND TUESDAY AS THE WEEKEND UPPER
LOW MOVES AWAY INTO CENTRAL CANADA, BUT LEAVES BEHIND WEAK RESIDUAL
TROUGHING FOR A CONTINUING CHANCE OF SHOWERS AND THUNDERSTORMS IN
NORTHERN MOUNTAINS. ON WEDNESDAY ANOTHER COLD UPPER LEVEL LOW WILL
APPROACH FROM THE BC COAST. THIS SECOND LOW IS NOT AS COLD AS THE
CURRENT LOW AND MODELS ARE NOT YET IN AGREEMENT ABOUT WHERE IT WILL
GO, SO FORECAST CONFIDENCE BEYOND WEDNESDAY IS LOW. FOR NOW WE'RE
GOING WITH THE WARMER ECMWF FORECAST WHICH TAKES THE LOW INLAND
ACROSS BC AND ALBERTA, AND KEEPS OUR CWA GENERALLY DRY WITH
TEMPERATURES CLOSE TO NORMAL. WE ALSO HAVE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS OVER NORTHERN MOUNTAINS THURSDAY AND
FRIDAY. THE GFS, ON THE OTHER HAND, WOULD BRING THE LOW ALL THE WAY
SOUTH TO THE SOUTHERN PANHANDLE, WITH GREATER CHANCES OF SHOWERS AND
THUNDERSTORMS, AND TEMPERATURES WELL BELOW NORMAL AGAIN.
AVIATION /00Z SATURDAY THROUGH SUNDAY/
ISSUED 555 PM MDT FRI JUN 26 2026
GENERALLY VFR. SCATTERED/NUMEROUS SHOWERS AND THUNDERSTORMS
BRINGING LOCALIZED MVFR, ERRATIC GUSTS TO 25-35 KT, SMALL HAIL,
AND BRIEF HEAVY RAIN. LIGHTNING COVERAGE WILL DECREASE
OVERNIGHT, BUT INCREASE AGAIN SAT MORNING. MTNS OBSCURED.
SURFACE WINDS OUTSIDE OF STORMS: VARIABLE 5-15 KT, THEN W-NW
5-15 KT WITH GUSTS TO 20-25 KT AFTER SAT/16Z. WINDS ALOFT AT
10KFT MSL: W-SW 15-25 KT.
KBOI...GENERALLY VFR. PERIODS OF RAIN SHOWERS CONTINUING THROUGH
SATURDAY EVENING. THREAT OF THUNDERSTORMS THIS EVENING PRIOR TO
SAT/05Z, AND AGAIN SAT AFTERNOON. THUNDERSTORMS CAPABLE OF
GUSTS TO 25-35 KT, BRIEF HEAVY RAIN WITH LOWERED VIS, AND SMALL
HAIL. SURFACE WINDS: VARIABLE 5-15 KT THIS EVENING, ESPECIALLY
AROUND SHOWER ACTIVITY. THEN, W-NW 5-15 KT OVERNIGHT AND SAT.
WEEKEND OUTLOOK...NUMEROUS SHOWERS THROUGH SUNDAY. LIGHTNING
ACTIVITY WILL TAPER OFF FOR SAT NIGHT/SUNDAY. MTN OBSCURATION.
LOCAL MVFR/IFR OVER MOUNTAINS IN RAIN/SNOW. SNOW LEVEL LOWERING
TO 6500-7500FT MSL SUNDAY MORNING. GUSTY WEST-NORTHWEST SURFACE
WINDS SUNDAY AFTERNOON.
BOI WATCHES/WARNINGS/ADVISORIES
ID...RED FLAG WARNING UNTIL 6 AM MDT SATURDAY FOR IDZ400-420-423-
424-426.
OR...RED FLAG WARNING UNTIL 6 AM MDT /5 AM PDT/ SATURDAY FOR
ORZ670>674.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....SH
SHORT TERM...JDS
LONG TERM....LC
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