079
FXUS65 KBOI 180819
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
219 AM MDT THU SEP 18 2025
SHORT TERM...TODAY THROUGH SATURDAY NIGHT
SUNNY AND WARM
AGAIN TODAY UNDER PERSISTENT UPPER LEVEL HIGH PRESSURE.
MOISTURE IN SOUTHERN CALIFORNIA, WITH REMNANTS OF FORMER
TROPICAL STORM MARIO, WILL SURGE NORTHWARD TODAY WITH A WEAK
UPPER LOW, AND RAPIDLY INCREASE MIDDLE AND HIGH CLOUDS IN OUR
CWA TONIGHT. LOW LEVELS WILL STAY DRY AND NO RAIN IS EXPECTED
IN OUR CWA THROUGH FRIDAY NIGHT, BUT THE CLOUDS WILL LIMIT
NIGHTTIME COOLING AND DAYTIME WARMING FROM PREVIOUS FORECASTS.
ON SATURDAY THE DISSIPATING UPPER LOW WILL GENERATE A 10-20
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS NEAR THE NV BORDER,
DRYING SATURDAY NIGHT. SMOKE FROM WILDFIRES WILL STAY MAINLY
ALOFT WITH LITTLE IF ANY SMOKE NEAR THE SURFACE.
LONG TERM...SUNDAY THROUGH THURSDAY
SATURDAY NIGHT'S CLOUDS
WILL BE SWEPT EAST ON SUNDAY BY A STRONGER GULF OF ALASKA UPPER
TROUGH COMING INLAND ACROSS THE NW STATES. THIS TROUGH WILL
PUSH A SURFACE COLD FRONT ACROSS OUR CWA, WITH A 20-30 PERCENT
CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR NORTHERN CWA
MOUNTAINS, AND GUSTY WEST/NORTHWEST WINDS OVER SOUTHERN PARTS OF
OUR CWA. THEN CLEARING AND COOLING SUNDAY NIGHT THROUGH MONDAY
AS THE COLD FRONT AND UPPER TROUGH MOVE RAPIDLY EAST. SUNNY AND
WARMER TUESDAY UNDER A NEW UPPER RIDGE BEHIND THE DEPARTING
TROUGH. ANOTHER UPPER LOW IS FORECAST IN FROM SOUTHERN
CALIFORNIA WEDNESDAY BUT MODELS DIFFER WIDELY ON THE TRACK OF
THAT LOW. FOR NOW WE'RE FORECASTING A 10-20 PERCENT CHANCE OF
SHOWERS AND THUNDERSTORMS IN ALL AREAS WEDNESDAY, WITH
TEMPERATURES AS WARM AS TUESDAY.
AVIATION
VFR. SMOKE LAYERS ALOFT PRODUCING SOME REDUCTION
IN VISIBILITY. SURFACE WINDS: E-S 5-15KT. WINDS ALOFT AT 10KFT
MSL: SW 5-10 KT.
KBOI...VFR WITH LIGHT WINDS. SMOKE LAYERS ALOFT.
WEEKEND OUTLOOK...VFR. BROKEN TO OVERCAST MIDDLE AND HIGH
CLOUDS THROUGH THE WEEKEND. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS NEAR THE NV BORDER SATURDAY AFTERNOON. NORTH
PACIFIC COLD FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN AREAS SUNDAY, AND GUSTY
WEST/NORTHWEST WINDS TO SOUTHERN AREAS. CLEARING WEST TO
EAST LATE SUNDAY.
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
SHORT TERM...LC
LONG TERM....LC
AVIATION.....LC
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