139
FXUS65 KBOI 290018
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
618 PM MDT SUN JUN 28 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON AND EVENING ACROSS SOUTHWEST IDAHO.
- PRECIPITATION WILL PERSIST ACROSS THE WEST CENTRAL MOUNTAINS
THROUGH MONDAY, WITH ANOTHER ROUND OF SHOWERS RETURNING
TUESDAY AFTERNOON.
- WARMER AND DRIER CONDITIONS TUESDAY THROUGH THURSDAY.
SHORT TERM /THROUGH TUESDAY NIGHT/
ISSUED 214 PM MDT SUN JUN 28 2026
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE THIS
AFTERNOON AND EVENING, WITH THE MAIN FOCUS ACROSS SOUTHWEST IDAHO
AS MOISTURE MOVES IN FROM THE NORTH ON THE BACK SIDE OF THE UPPER
LEVEL LOW. THE GREATEST CHANCE FOR THUNDERSTORM ACTIVITY WILL BE
OVER THE HIGHER TERRAIN SOUTH OF THE SNAKE RIVER PLAIN DURING
PEAK AFTERNOON AND EVENING HEATING BEFORE TAPERING OFF TONIGHT.
THERE IS A 30% CHANCE FOR THESE LIGHT RAIN SHOWERS TO REACH THE
TREASURE AND MAGIC VALLEYS TONIGHT THROUGH MONDAY MORNING, THOUGH
RAINFALL LOOKS TO BE MINIMAL. SHOWERS WILL CONTINUE ACROSS THE
WEST CENTRAL MOUNTAINS THROUGH MONDAY, FINALLY COMING TO AN END
MONDAY NIGHT AS THE PARENT LOW MOVES EAST INTO THE NORTHERN PLAINS.
THE CENTRAL MOUNTAINS WILL SEE ADDITIONAL PRECIPITATION TOTALS
BETWEEN 0.25 AND 0.75 INCHES THROUGH MONDAY. AREAS ABOVE 7500 FEET
COULD SEE AN ADDITIONAL 1 TO 3 INCHES OF SNOWFALL TONIGHT.
A BROAD UPPER LEVEL TROUGH REMAINS OVER THE AREA ON TUESDAY.
THIS PERSISTENT LARGE-SCALE PATTERN WILL ALLOW A WEAK SHORTWAVE
PASSAGE TO CROSS THE REGION, TRIGGERING ANOTHER ROUND OF SHOWERS
ACROSS THE WEST CENTRAL MOUNTAINS. TEMPERATURES WILL REMAIN WELL
BELOW NORMAL, TRACKING ROUGHLY 10 TO 15 DEGREES BELOW SEASONAL
AVERAGES THROUGH THE SHORT TERM PERIOD UNDER THE INFLUENCE OF
THE TROUGH.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
ISSUED 214 PM MDT SUN JUN 28 2026
TROUGHING OVER THE REGION WILL SUPPORT ISOLATED SHOWERS AND
THUNDERSTORMS ACROSS THE HIGHER TERRAIN OF SW IDAHO, AND COOLER
THAN NORMAL CONDITIONS THROUGH THE END OF THE WEEK. MOST GUIDANCE
SHOWS THIS TROUGH DEEPENING JUST TO OUR WEST THROUGHOUT THE WEEK.
WITH FLOW TAKING ON MORE OF A SOUTHWESTERLY COMPONENT,
TEMPERATURES WILL STEADILY WARM. AS OF NOW IT APPEARS THAT THIS
WARMING TREND WILL BE MORE GRADUAL IN EASTERN OREGON. COME
FRIDAY, THE TROUGH FINALLY LOOKS TO PROGRESS EAST OF OUR AREA.
THIS WILL TEMPORARILY HINDER THE WARMING TREND ON FRIDAY, BEFORE
A BUILDING RIDGE BEHIND THE TROUGH BRINGS TEMPERATURES BACK UP
TO NEAR NORMAL. THE TIMELY EXIT OF THIS TROUGH WILL MAKE WAY FOR
A PLEASANT FOURTH OF JULY, WITH NEAR NORMAL TEMPERATURES AND
DRY CONDITIONS. THE PATTERN EVOLUTION BECOMES MORE UNCERTAIN TO
END THE PERIOD, ALTHOUGH THE GRAND ENSEMBLE FAVORS CONTINUED
RIDGING AND THEREFORE CONTINUED WARM AND DRY CONDITIONS.
AVIATION /00Z MONDAY THROUGH TUESDAY/
ISSUED 603 PM MDT SUN JUN 28 2026
VFR. AREA OF LIGHT PRECIP SPANNING ACROSS FAR E OREGON AND
SOUTHWEST/WEST-CENTRAL IDAHO THIS EVENING, ALONG WITH ISOLATED
T-STORMS NEAR ID-NV BORDER. MVFR/IFR IN MTN SHOWERS, WITH LIGHT
SNOW ABOVE 7KFT MSL. MTNS OBSCURED. SHOWERS CONTINUING MONDAY,
WITH REDUCED LIGHTNING THREAT. SURFACE WINDS: SW-NW 5-15 KT.
GUSTS TO 15-25 KT THROUGH SUNSET, RETURNING MON AFTERNOON. WINDS
ALOFT AT 10KFT MSL: NW 15-25 KT.
KBOI...VFR. PERIODS OF LIGHT RAIN BEFORE MON/09Z. A 20% CHANCE
OF RAIN SHOWERS RETURNING MONDAY AFTERNOON. FOOTHILLS OBSCURED
WITH SCT-BKN CLOUDS BETWEEN 5000-7000 FT AGL. SURFACE WINDS: NW
10-15 KT WITH GUSTS TO 20-25 KT THROUGH SUNSET, THEN VARIABLE
OR SE AROUND 5 KT OVERNIGHT.
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.....SH
SHORT TERM...JDS
LONG TERM....NF
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