730
FXUS65 KBOI 250604
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1204 AM MDT SAT APR 25 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- WIDESPREAD FROST AND AREAS OF FREEZING TEMPERATURES LATE
TONIGHT INTO SATURDAY MORNING.
- FROST LIKELY IN LOWER VALLEYS SUNDAY AND MONDAY MORNINGS.
- REMAINING UNSETTLED THROUGH THE WEEKEND AND INTO EARLY NEXT
WEEK. TEMPERATURES WILL GRADUALLY WARM TOWARD NORMAL BY MID
WEEK.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED 219 PM MDT FRI APR 24 2026
THE REGION REMAINS UNDER THE INFLUENCE OF A COOL NORTHWEST FLOW
AS A LARGE UPPER LOW SITS OVER WESTERN CANADA. THIS WILL
CONTINUE ISOLATED RAIN AND SNOW SHOWERS ACROSS THE CENTRAL IDAHO
MOUNTAINS THROUGH THIS EVENING. FOR TONIGHT, CLEAR SKIES AND
LIGHT WINDS WILL ALLOW FOR EFFICIENT RADIATIONAL COOLING.
TEMPERATURES ACROSS MOST OF THE TREASURE VALLEY AND WESTERN
MAGIC VALLEY ARE EXPECTED (GREATER THAN 80% CHANCE) TO DROP
BELOW FREEZING. A FREEZE WARNING REMAINS IN EFFECT FOR THESE
AREAS FOR SATURDAY MORNING.
ON SATURDAY, A PACIFIC LOW PRESSURE SYSTEM BEGINS MOVING INLAND
FROM CALIFORNIA INTO THE GREAT BASIN, BRINGING A SLIGHTLY
WARMER AND MORE MOIST AIR MASS. THIS WILL INCREASE MOISTURE AND
INSTABILITY OVER THE HIGHER TERRAIN FOR SHOWERS, ESPECIALLY
ALONG THE NEVADA BORDER. THE LOWER VALLEYS WILL SEE MOSTLY DRY
CONDITIONS ON SATURDAY. BY SUNDAY AND MONDAY, THE UPPER LEVEL
LOW WEAKENS INTO AN OPEN TROUGH AS IT CONTINUES EAST ACROSS THE
SOUTHERN GREAT BASIN. THIS PERSISTENT UNSETTLED PATTERN WILL
MAINTAIN LOW CHANCES FOR AFTERNOON MOUNTAIN RAIN AND SNOW
SHOWERS. A SLIGHT CHANCE (15% CHANCE) OF THUNDERSTORMS ALONG THE
NEVADA BORDER IS POSSIBLE ESPECIALLY ON SUNDAY AFTERNOON AS THE
TROUGH MOVES THROUGH.
COLD OVERNIGHT TEMPERATURES WILL CONTINUE TO BE A CONCERN FOR
SENSITIVE VEGETATION SUNDAY AND MONDAY MORNINGS. WHILE SUNDAY
AND MONDAY MAY STAY JUST WARM ENOUGH TO AVOID A WIDESPREAD
FREEZE, A FROST ADVISORY FOR THE TREASURE AND WESTERN MAGIC
VALLEYS WILL LIKELY (80% CHANCE) BE NEEDED AS LOWS DIP BETWEEN
32 TO 36 DEGREES. TEMPERATURES THROUGH THE PERIOD WILL REMAIN 5
TO 10 DEGREES BELOW SEASONAL NORMALS.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED 219 PM MDT FRI APR 24 2026
A TROUGH EXTENDING FROM A LOW CENTERED OVER CANADA WILL
CONTINUE TO LINGER OVER THE REGION, BRINGING HIGH TERRAIN
SHOWERS (30-50% CHANCE) ON MONDAY AND TUESDAY AND TEMPERATURES
ABOUT 5-10 DEGREES BELOW NORMAL. SHOWERS WILL GENERALLY BE
LIGHT, WITH MINIMAL ACCUMULATION. SNOW LEVELS WILL STAY AROUND
5000-6000 FEET, DIPPING DOWN TO 4500 FEET OVERNIGHT MONDAY INTO
TUESDAY. HIGH PRESSURE WILL THEN MOVE INTO THE REGION LATE
TUESDAY, BRINGING A WARMING TREND THROUGH THE END OF THE LONG
TERM PERIOD. TEMPERATURES WILL REACH ABOUT 5-10 DEGREES ABOVE
NORMAL, WITH ABOUT A 10% CHANCE THAT THE TREASURE VALLEY WILL
HIT 80F. LINGERING MOUNTAIN SHOWERS ARE POSSIBLE THROUGH
THURSDAY WITH THIS WARMING TREND, BUT FORECAST CONFIDENCE IS LOW
(10% CHANCE).
AVIATION /06Z SATURDAY THROUGH SUNDAY/
ISSUED 1159 PM MDT FRI APR 24 2026
VFR WITH MOSTLY CLEAR SKIES OVERNIGHT THROUGH EARLY AFTERNOON.
SCT-BKN HIGH CLOUDS MOVING IN DURING THE AFTERNOON/EVENING.
ISOLATED MOUNTAIN SNOW SHOWERS RETURNING IN THE AFTERNOON NEAR
KMYL AND KBKE, WITH LOCALIZED MVFR/IFR CONDITIONS AND MOUNTAIN
OBSCURATION POSSIBLE IN SHOWERS. SCATTERED SHOWERS NEAR THE NV
BORDER. SURFACE WINDS: VARIABLE LESS THAN 10 KT OVERNIGHT
THROUGH MORNING, THEN W-NW 5-10 KT IN THE AFTERNOON. WINDS ALOFT
AT 10KFT MSL: NW 10-25 KT SHIFTING TO SW 10-20 KT IN THE
MORNING AFTER SAT/12Z.
KBOI...VFR WITH CLEAR SKIES OVERNIGHT THROUGH THE MORNING.
SURFACE WINDS: VARIABLE LESS THAN 6 KT.
SUNDAY OUTLOOK...GENERALLY VFR WITH LOCALIZED MVFR-IFR
CONDITIONS IN SCATTERED SHOWERS OVER HIGH TERRAIN IN THE AFTERNOON.
LOW CONFIDENCE OF THUNDERSTORMS (10-20% CHANCE) NEAR THE NV
BORDER. MOUNTAINS OBSCURED AT TIMES IN PRECIPITATION. SURFACE
WINDS W-NW 5-15 KT WITH GUSTS TO 25 KT.
BOI WATCHES/WARNINGS/ADVISORIES
ID...FREEZE WARNING UNTIL 9 AM MDT SATURDAY FOR IDZ012-014-016.
OR...FREEZE WARNING UNTIL 9 AM MDT /8 AM PDT/ SATURDAY FOR ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....JY/ST
SHORT TERM...JDS
LONG TERM....SA
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