263
FXUS65 KBOI 281957
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
157 PM MDT MON SEP 28 2026
KEY MESSAGES
- BREEZY NORTHWEST WINDS IN THE SNAKE PLAIN EACH AFTERNOON
THROUGH WEDNESDAY.
- FAIR SKIES AND WARMER TEMPERATURES THROUGH THIS WEEKEND.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
AS A TROUGH MOVES EAST, HIGH PRESSURE BUILDS TO THE SOUTH OF OUR
FORECAST AREA. ZONAL FLOW WILL CAP OFF THE HIGH PRESSURE,
LEADING TO A MODERATED WARMING TREND UP TO ABOUT 5 DEGREES ABOVE
NORMAL IN THE SHORT TERM. DRY/FAIR WEATHER IS EXPECTED THROUGH
THE PERIOD, AS MOISTURE IN THE FLOW IS POSITIONED ALONG THE
CANADA-US BORDER. WEST TO NORTHWEST SURFACE WINDS WILL BECOME
BREEZY EACH AFTERNOON IN THE SNAKE PLAIN, ESPECIALLY BETWEEN
BOISE AND TWIN FALLS. THE BREEZY 20-30 MPH PEAK WIND GUSTS OCCUR
IN AN AREA WHERE FORECAST MINIMUM RELATIVE HUMIDITIES ARE AROUND
15-20%, CREATING ELEVATED FIRE WEATHER THOUGH IN A VERY
LOCALIZED PORTION OF THE HIGH DESERT. SURFACE WINDS BEGIN TO
TAPER OFF HEADING INTO THE LONG TERM FORECAST.
LONG TERM /THURSDAY THROUGH MONDAY/
THE AREA WILL REMAIN UNDER A FLATTENED RIDGE NORTH OF A MASSIVE
PACIFIC HIGH SLOWLY BUILDING INTO THE GREAT BASIN REGION. THIS
CONTINUOUS RIDGING PATTERN WILL FAVOR CLEAR SKIES, DRY CONDITIONS,
AND THE RETURN OF WARMER THAN NORMAL TEMPERATURES THURSDAY THROUGH
FRIDAY. A WEAK SHORTWAVE TROUGH PASSING NORTH OF OUR AREA LATE
FRIDAY MAY BRING IN SOME HIGH CLOUD COVERAGE, POSSIBLY MODERATING
THE DAYTIME TEMPERATURES ON SATURDAY. OTHERWISE, BROAD PACIFIC
RIDGING WILL DOMINATE THE REGION SUNDAY THROUGH EARLY NEXT WEEK,
CONTINUING A MUCH WARMER AND DRIER THAN NORMAL PATTERN IN THE
EXTENDED OUTLOOK.
AVIATION /18Z MONDAY THROUGH TUESDAY/
ISSUED 1153 AM MDT MON SEP 28 2026
VFR WITH CLEARING SKIES THIS AFTERNOON THROUGH TONIGHT. PATCHY
MORNING FOG/LOW STRATUS IN SHELTERED MOUNTAIN VALLEYS TUESDAY
MORNING. SURFACE WINDS: W-NW 5-15 KT, AFTERNOON GUSTS TO 25 KT
FROM KBOI TO THE SOUTH/EAST. WINDS ALOFT AT 10KFT MSL: W-NW 5-15
KT.
KBOI...VFR WITH CLEAR SKIES. SURFACE WINDS: W-NW 4-10 KT,
INCREASING TO 10-15 KT WITH GUSTS TO 20-25 KT THIS AFTERNOON
AFTER 20Z, LOWERING TO 6-11 KT IN THE EVENING AFTER TUE/02Z.
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...JM
LONG TERM....JY
AVIATION.....JY
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