798
FXUS65 KBOI 132009
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
209 PM MDT TUE OCT 13 2026
KEY MESSAGES
- COLD MORNING TEMPERATURES THIS MORNING AND WEDNESDAY MORNING
WILL BRING PATCHY FROST AND NEAR-FREEZING CONDITIONS, WITH
FROST ADVISORIES IN EFFECT FOR THE SNAKE PLAIN VALLEY AREAS.
- WARM AND DRY CONDITIONS WEDNESDAY THROUGH THE WEEKEND.
TEMPERATURES REACHING UP TO 10 DEGREES ABOVE NORMAL BY
FRIDAY.
SHORT TERM /THROUGH THURSDAY NIGHT/
AN UPPER LEVEL RIDGE OVER THE NORTHEAST PACIFIC CONTINUES TO
AMPLIFY, MAINTAINING A DRY, NORTHERLY FLOW ALOFT ACROSS
SOUTHEAST OREGON AND SOUTHWEST IDAHO. AT THE SURFACE, A COOL
HIGH PRESSURE SYSTEM CENTERED OVER THE GREAT BASIN WILL LINGER
THROUGH THURSDAY.
CLEAR SKIES, DRY AIR, AND LIGHT TO CALM WINDS TONIGHT WILL
CREATE IDEAL CONDITIONS FOR STRONG RADIATIONAL COOLING. LOW
TEMPERATURES WEDNESDAY MORNING ARE EXPECTED TO RUN ROUGHLY 2 TO
3 DEGREES COLDER THAN TUESDAY MORNING ACROSS MOST LOW ELEVATION
LOCATIONS. VALUES IN THE TREASURE VALLEY ARE EXPECTED TO DROP
INTO THE LOW TO MID 30S, SUPPORTING WIDESPREAD FROST
DEVELOPMENT. A FROST ADVISORY REMAINS IN EFFECT. FURTHER EAST,
COLDER AIR POOLING INTO THE WESTERN MAGIC VALLEY WILL DRIVE
TEMPERATURES DOWN TO AROUND 28 TO 32 DEGREES, WHERE A FREEZE
WARNING HAS BEEN ISSUED.
CONDITIONS WILL REMAIN QUIET AND DRY ON WEDNESDAY AND THURSDAY.
HIGH TEMPERATURES ON WEDNESDAY WILL TOP OUT IN THE MID 60S FOR
LOWER VALLEYS, WHICH IS ROUGHLY AROUND SEASONAL AVERAGES. AS THE
RIDGE AXIS NUDGES SLIGHTLY CLOSER ON THURSDAY, HEIGHTS ALOFT
WILL RECOVER SLIGHTLY. EXPECT HIGH TEMPERATURES TO REACH THE
UPPER 60S TO LOW 70S FOR THE LOWER VALLEYS, ACCOMPANIED BY LIGHT
DIURNAL WINDS AND CLEAR SKIES.
LONG TERM /FRIDAY THROUGH TUESDAY/
WARM AND DRY CONDITIONS WILL
END THE WEEK WITH HIGH PRESSURE ALOFT OVER THE GREAT BASIN; THIS
WILL KEEP TEMPERATURES AT 5-10 DEGREES ABOVE NORMAL. A SHORTWAVE AND
ASSOCIATED WEAK COLD FRONT ON SUNDAY WILL HELP DROP TEMPERATURES A
FEW DEGREES, ALTHOUGH STILL IN THAT ABOVE NORMAL RANGE. BY MID-WEEK
NEXT WEEK, THERE IS GOOD AGREEMENT ON ANOTHER TROUGH DIGGING DOWN
FROM THE GULF OF ALASKA INTO THE WESTERN CONUS. THIS SYSTEM WILL
BRING A MORE SIGNIFICANT COOL DOWN AND WIDESPREAD PRECIPITATION
CHANCES. BELOW NORMAL TEMPERATURES ARE FAVORED AGAIN COME TUESDAY.
AVIATION /18Z TUESDAY THROUGH WEDNESDAY/
ISSUED 1201 PM MDT TUE OCT 13 2026
VFR. LOW CLOUDS CONTINUING NEAR KTWF/KJER EARLY THIS AFTERNOON,
CLEARING OUT TO BE MOSTLY SUNNY AREA-WIDE BY LATE AFTERNOON.
SURFACE WINDS: W-NW 5-15 KT WITH GUSTS TO 20-25 KT THIS
AFTERNOON, THEN VARIABLE 5-10 KT OVERNIGHT. WINDS ALOFT AT
10KFT MSL: N 10-25 KT.
KBOI...VFR UNDER CLEAR SKIES. SURFACE WINDS: NW 10-15 KT WITH
GUSTS TO AROUND 22 KT THIS AFTERNOON. BECOMING VARIABLE UNDER 8
KT OVERNIGHT.
BOI WATCHES/WARNINGS/ADVISORIES
ID...FROST ADVISORY UNTIL 10 AM MDT WEDNESDAY FOR IDZ012-014.
FREEZE WARNING UNTIL 10 AM MDT WEDNESDAY FOR IDZ016.
OR...FROST ADVISORY UNTIL 10 AM MDT /9 AM PDT/ WEDNESDAY FOR ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...JDS
LONG TERM....NF
AVIATION.....NF
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