319
FXUS65 KBOI 101738
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1138 AM MDT FRI JUL 10 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- HEAT ADVISORY TODAY AND SATURDAY FOR LOWER ELEVATIONS OF
SOUTHWEST IDAHO AND SOUTHEAST OREGON.
- HOT AND DRY, WITH BREEZY AFTERNOON WINDS THROUGH THE WEEKEND.
- SHOWER AND THUNDERSTORM CHANCES RETURN EARLY NEXT WEEK WITH
THE ARRIVAL OF MONSOON MOISTURE.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED 304 AM MDT FRI JUL 10 2026
STRONG HIGH PRESSURE CENTERED OVER THE DESERT SW WILL EXPAND
NORTHWARD TODAY THROUGH THE WEEKEND, POSITIONING SW IDAHO AND SE
OREGON IN SOUTHWEST FLOW ALOFT. TEMPERATURES ARE EXPECTED TO
HEAT UP IN THE LOWER VALLEYS TO UPPER 90S-105 DEGREES TODAY AND
SATURDAY. RELATIVELY WARM OVERNIGHT LOWS ARE ALSO ANTICIPATED,
RESULTING IN MINIMAL RELIEF FROM HEAT. A HEAT ADVISORY REMAINS
IN EFFECT ACROSS WEISER BASIN, THE WESTERN SNAKE PLAIN, AND
AREAS SOUTH TO THE NV BORDER THIS AFTERNOON THROUGH SATURDAY DUE
TO MODERATE/MAJOR HEAT RISK LEVELS. MEANWHILE, SURFACE WINDS
WILL BECOME BREEZY TODAY THROUGH THE WEEKEND ACROSS SOUTHEAST
OREGON AND (MAINLY) THE HIGHER TERRAIN OF SW IDAHO AS STRENGTHENING
MID-LEVEL FLOW MIXES TO THE SURFACE. TEMPERATURES WILL COOL BY
A COUPLE OF DEGREES SUNDAY WITH AN INFLUX OF HIGH CLOUDS, BUT
HEAT IMPACTS ARE EXPECTED TO CONTINUE.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED 304 AM MDT FRI JUL 10 2026
MID/HIGH LEVEL MOISTURE AND PRECIPITABLE WATER VALUES WILL RAMP UP
MONDAY AND TUESDAY AS MONSOON MOISTURE MAKES ITS WAY NORTH INTO THE
REGION. AS A RESULT, SHOWER AND THUNDERSTORM CHANCES INCREASE
STARTING MONDAY AFTERNOON, FAVORING HIGHER TERRAIN. INITIAL
CONVECTION WILL LEAN DRIER AND OUTFLOW DOMINANT FROM PRECEDENT
DRY LOW- LEVELS, BUT SHOULD SOON BECOME HEAVIER RAIN PRODUCERS
TUESDAY INTO WEDNESDAY AS PWAT VALUES REACH 1.00"+ AND LOW-
LEVELS MOISTEN. SHOWER/THUNDERSTORM CHANCES WILL EXPAND TO MOST
AREAS BY TUESDAY, THOUGH NBM/WPC GUIDANCE STILL STRUGGLES TO
RESOLVE THIS TRANSITION DESPITE THE ENHANCED COVERAGE IN
DETERMINISTIC MODELS. MEANWHILE, A BROAD PACIFIC TROUGH IS
FORECAST TO MOVE SOUTH ALONG THE WEST COAST MONDAY AND TUESDAY,
BUT MODELS DISAGREE ON WHEN TO BRING THE TROUGH ONSHORE AND PUSH
MONSOON MOISTURE TOWARD THE EAST. THE TROUGH EVOLUTION WILL
DETERMINE WHETHER SHOWERS AND THUNDERSTORMS CONTINUE THROUGH THE
REST OF THE WEEK/NEXT WEEKEND, OR GRADUALLY DECREASE AROUND
MID-WEEK. OVERALL, SOUTHERLY FLOW IS EXPECTED TO PERSIST THROUGH
FRIDAY AND SUPPORT HOT TEMPERATURES AREA-WIDE.
AVIATION /18Z FRIDAY THROUGH SATURDAY/
ISSUED 1130 AM MDT FRI JUL 10 2026
VFR. AREAS OF REDUCED VISIBILITY FROM WILDFIRE SMOKE. HIGH DENSITY
ALTITUDE DUE TO HEAT. ISOLATED CONVECTION OVER CENTRAL ID MOUNTAINS
AND SOUTH-CENTRAL ID THIS AFTERNOON. SURFACE WINDS: LIGHT AND
VARIABLE. BECOMING SW-W 10-15 KT WITH GUSTS TO 20-30 KT OVER SE
OREGON AND HIGHER TERRAIN OF SW IDAHO IN THE AFTERNOON. WINDS
ALOFT AT 10KFT MSL: SW 5-15 KT.
KBOI...VFR. HIGH DENSITY ALTITUDE DUE TO HEAT. VISIBILITY REDUCED AT
TIMES BY WILDFIRE SMOKE IN FOOTHILLS NE OF KBOI. SURFACE WINDS: SE-S
5-10 KT, BECOMING NW-N 5-10 KT LATE AFTERNOON / EARLY EVENING.
WEEKEND OUTLOOK...VFR. AREAS OF REDUCED VISIBILITY FROM WILDFIRE
SMOKE. HIGH DENSITY ALTITUDE DUE TO HEAT, ESPECIALLY SATURDAY.
SURFACE WINDS: SW-NW 5-15 KT SAT/SUN. AFTERNOON GUSTS TO 20-30
KT ACROSS SE OREGON AND (MAINLY) THE HIGHER TERRAIN OF SW IDAHO.
BOI WATCHES/WARNINGS/ADVISORIES
ID...HEAT ADVISORY UNTIL 9 PM MDT SATURDAY FOR IDZ012-014>016-030-
033.
OR...HEAT ADVISORY UNTIL 9 PM MDT /8 PM PDT/ SATURDAY FOR ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....CH
SHORT TERM...SH
LONG TERM....SH
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