520
FXUS65 KBOI 111135
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
535 AM MDT SAT JUL 11 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- HEAT ADVISORY CONTINUES TODAY FOR LOWER ELEVATIONS OF
SOUTHWEST IDAHO AND SOUTHEAST OREGON, EXTENDING THROUGH MONDAY
EVENING FOR SOUTH-CENTRAL IDAHO.
- BREEZY AFTERNOON WINDS THROUGH THE WEEKEND.
- SHOWERS AND THUNDERSTORMS RETURN LATE MONDAY THROUGH TUESDAY
NIGHT WITH THE ARRIVAL OF MONSOON MOISTURE.
- HOT TEMPERATURES WILL LAST THROUGH THE WEEK, ALONG WITH
SLIGHT THUNDERSTORM CHANCES OVER THE HIGHER TERRAIN EACH DAY.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED 302 AM MDT SAT JUL 11 2026
PREVAILING SOUTH-SOUTHWEST FLOW ALOFT WILL BRING ANOTHER DAY OF
HOT TEMPERATURES, DRY CONDITIONS, AND BREEZY WINDS THIS
AFTERNOON. TODAY IS EXPECTED TO BE THE HOTTEST DAY OF THE
ENTIRE FORECAST PERIOD, PEAKING AT UPPER 90S TO 106 FOR LOWER
ELEVATIONS. CONSEQUENTLY, A HEAT ADVISORY REMAINS IN EFFECT
UNTIL 9PM MDT TONIGHT FOR THE UPPER WEISER BASIN, SNAKE PLAIN,
AND AREAS SOUTH TO THE NV BORDER. THE ADVISORY WILL EXTEND
THROUGH MONDAY EVENING FOR SOUTH-CENTRAL IDAHO DUE TO THE
CONTINUATION OF MODERATE/MAJOR HEAT RISK FOR THAT AREA.
INCREASING HIGH CLOUDS TODAY WILL KEEP OVERNIGHT LOW
TEMPERATURES RELATIVELY WARM TONIGHT, LIMITING HEAT-RELIEF FOR
LOWER ELEVATIONS. CLOUD COVER AND BREEZY WINDS WILL PERSIST INTO
SUNDAY, THOUGH A FEW DEGREES OF COOLING CAN BE EXPECTED FOR
MOST AREAS AS THE STRONG HIGH PRESSURE SHIFTS SLIGHTLY TOWARD
THE EAST. BY MONDAY, AN INFLUX OF MID-LEVEL MONSOONAL MOISTURE
WILL BOOST PRECIPITABLE WATER VALUES TO AROUND 1.00", TRIGGERING
SHOWERS AND THUNDERSTORMS PRIMARILY OVER HIGHER TERRAIN IN THE
AFTERNOON AND EVENING. WITH UNSTABLE CONDITIONS AND HOT SURFACE
TEMPERATURES IN PLACE, CONVECTIVE ACTIVITY WILL POSE A THREAT
OF GUSTY OUTFLOW WINDS, HEAVY DOWNPOURS, AND CLOUD TO GROUND
LIGHTNING.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED 302 AM MDT SAT JUL 11 2026
MID-LEVEL MONSOONAL MOISTURE WILL CONTINUE STREAMING IN FROM
THE SOUTH ON TUESDAY, MAINTAINING PWAT VALUES AT OR ABOVE 1.00".
THIS WILL ENHANCE SHOWER AND THUNDERSTORM COVERAGE ACROSS
SOUTHEAST OREGON AND SOUTHWEST IDAHO BY TUESDAY AFTERNOON.
HEAVY DOWNPOURS ARE LIKELY WITH STRONGER CONVECTION, ALONG WITH
GUSTY, RAIN-DRIVEN COLD POOLS AS LOW-LEVELS MOISTEN FURTHER.
LATE TUESDAY INTO WEDNESDAY, AN INCOMING PACIFIC TROUGH WILL
MOVE INLAND, NUDGING THE BULK OF THE MONSOONAL MOISTURE
EASTWARD BY WEDNESDAY. AS A RESULT, STORM CHANCES WILL DECREASE
FOR WEDNESDAY AND THURSDAY, THOUGH HIGHER TERRAIN (PRIMARILY IN
SW IDAHO) REMAINS SUSCEPTIBLE TO CONVECTIVE DEVELOPMENT BOTH
DAYS. DESPITE THE EASTWARD SHIFT OF THE HIGH PRESSURE CENTER,
TEMPERATURES WILL REMAIN HOT ALL WEEK...HOVERING AROUND 5
DEGREES ABOVE NORMAL. WHILE MODEL GUIDANCE BEGINS TO DIVERGE
TOWARD THE END OF THE WEEK REGARDING MOISTURE PLACEMENT, A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS REMAINS OVER HIGHER
TERRAIN. MODELS STAY IN GENERAL AGREEMENT THAT HOT SOUTHWEST
FLOW ALOFT WILL DOMINATE THROUGH AT LEAST FRIDAY/SATURDAY.
AVIATION /12Z SATURDAY THROUGH SUNDAY/
ISSUED 532 AM MDT SAT JUL 11 2026
VFR WITH INCREASING HIGH CLOUDS THIS AFTERNOON. AREAS OF
REDUCED VISIBILITY FROM WILDFIRE SMOKE/HAZE. HIGH DENSITY
ALTITUDE DUE TO HEAT. SURFACE WINDS: VARIABLE 5-15 KT THROUGH
MORNING, BECOMING SE-SW 5-15 KT IN THE AFTERNOON. AFTERNOON
GUSTS TO 20-30 KT, MAINLY OVER SOUTHEAST OR AND HIGH TERRAIN OF
SOUTHWEST ID. WINDS ALOFT AT 10KFT MSL: SW 15-30 KT.
KBOI...VFR WITH INCREASING HIGH CLOUDS THIS AFTERNOON.
VISIBILITY REDUCED AT TIMES BY WILDFIRE SMOKE IN FOOTHILLS NE OF
KBOI. HIGH DENSITY ALTITUDE DUE TO HEAT. SURFACE WINDS: E-S
5-12 KT.
SUNDAY OUTLOOK...VFR AND BKN-OVC HIGH CLOUDS. AREAS OF REDUCED
VISIBILITY FROM WILDFIRE SMOKE/HAZE. HIGH DENSITY ALTITUDE DUE
TO HEAT. SURFACE WINDS: SW-NW 5-15 KT WITH AFTERNOON GUSTS TO
20-25 KT. EXCEPT SW 10-20 KT WITH GUSTS 25-35 KT ACROSS SE
OREGON LATE AFTERNOON.
BOI WATCHES/WARNINGS/ADVISORIES
ID...HEAT ADVISORY UNTIL 9 PM MDT THIS EVENING FOR IDZ012-014-015-
033.
HEAT ADVISORY UNTIL 9 PM MDT MONDAY FOR IDZ016-030.
OR...HEAT ADVISORY UNTIL 9 PM MDT /8 PM PDT/ THIS EVENING FOR
ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....SH
SHORT TERM...SH
LONG TERM....SH
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