289
FXUS65 KBOI 250253
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
853 PM MDT THU APR 24 2025
DISCUSSION
ISOLATED SHOWERS AND EVEN A THUNDERSTORM EAST OF
MCCALL DISSIPATED THIS EVENING, OTHERWISE MOSTLY CLEAR SKIES
PREVAIL OVERNIGHT. MOISTURE AND INSTABILITY INCREASE FROM THE
SOUTH ON FRIDAY AHEAD OF A CLOSED UPPER LOW SITUATED OFF THE
CALIFORNIA COAST. INITIALLY, THERE IS A 15-30 PERCENT CHANCE OF
SHOWERS IN AREAS NEAR THE NEVADA BORDER IN THE MORNING, WITH
SHOWER CHANCES INCREASING AND EXPANDING NORTHWARD THROUGH THE
AFTERNOON. DAYTIME HEATING COMBINED WITH DYNAMICS WITH THE
APPROACHING UPPER LOW WILL SUPPORT A CHANCE OF THUNDERSTORMS
DURING THE AFTERNOON. THE STORMS ARE PROGGED BY THE HI-RES
MODELS TO INITIATE IN SOUTHERN AREAS, THEN MOVE NORTHWARD AND
COULD REACH PORTIONS OF THE SNAKE RIVER PLAIN MID-LATE
AFTERNOON. GUSTY WINDS TO 50 MPH, SMALL HAIL, AND BRIEF HEAVY
RAIN MAY ACCOMPANY THE STORMS. NO UPDATES.
AVIATION
VFR WITH SCT-BKN MID AND HIGH LEVEL CLOUDS. SURFACE
WINDS: VARIABLE 5-10 KT. WINDS ALOFT AT 10KFT: SE 5-15 KT.
KBOI...VFR. VARIABLE UP TO 5 KT BECOMING SE 5-10 KT BY FRI/06Z.
WEEKEND OUTLOOK... VFR. ACTIVE WEATHER THROUGH THE WEEKEND, WITH
CHANCES OF SHOWERS AND SLIGHT CHANCES OF AFTERNOON THUNDERSTORMS
FRIDAY-SUNDAY. SHOWERS/THUNDERSTORMS MAY RESULT IN AREAS OF
MVFR, MOUNTAIN OBSCURATION, AND PRODUCE GUSTY OUTFLOWS. SURFACE
WINDS INCREASING BY SUNDAY, WITH GUSTS UP TO 30 KT SUNDAY
AFTERNOON.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...A FEW SHOWERS
AND POSSIBLY A THUNDERSTORM MAY DEVELOP THIS AFTERNOON AND
EVENING OVER THE WEST CENTRAL MOUNTAINS OF IDAHO. OTHERWISE,
SKIES WILL REMAIN MOSTLY CLEAR TONIGHT.
MORE ACTIVE WEATHER IS EXPECTED FRIDAY AS MOISTURE AND UPPER-
LEVEL DYNAMICS INCREASE AHEAD OF A DEVELOPING CLOSED LOW OFF THE
NORTHERN CALIFORNIA COAST. CLOUDS WILL SPREAD ACROSS MUCH OF
THE AREA FRIDAY MORNING, WITH LIGHT SHOWERS LIKELY OVER
SOUTHEAST OREGON AND ALONG THE IDAHO/NEVADA BORDER. AS THE DAY
PROGRESSES, CLOUDS AND SHOWERS WILL LIFT NORTHWARD, ALLOWING FOR
SOME AFTERNOON CLEARING ACROSS MUCH OF SOUTHWEST IDAHO.
THIS CLEARING WILL ENHANCE SURFACE HEATING, BOOSTING SBCAPE
VALUES UP TO 600 J/KG ALONG THE IDAHO/NEVADA BORDER, WITH AROUND
30 KTS OF SHEAR. THESE CONDITIONS SHOULD SUPPORT LONGER-LIVED
THUNDERSTORMS. THE WESTWARD EXTENT OF STORM DEVELOPMENT WILL
DEPEND ON HOW MUCH CLOUD COVER PERSISTS OVER SOUTHEAST OREGON.
STORMS ARE EXPECTED TO INITIATE OVER THE HIGHER TERRAIN NEAR THE
IDAHO/NEVADA BORDER AND TRACK NORTHWARD INTO THE SNAKE RIVER
PLAIN AND CENTRAL IDAHO MOUNTAINS LATE FRIDAY AFTERNOON INTO THE
EVENING. THE STRONGEST STORMS MAY PRODUCE WIND GUSTS UP TO 50
MPH, BRIEF HEAVY RAIN, AND SMALL HAIL.
SHOWERS AND THUNDERSTORMS MAY LINGER INTO LATE FRIDAY EVENING,
GRADUALLY TAPERING OFF BY MID-MORNING SATURDAY. ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS IS LIKELY SATURDAY AFTERNOON, WITH THE
BEST INSTABILITY NORTH OF A BURNS–ONTARIO–MCCALL LINE.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD.
LONG TERM...SUNDAY THROUGH THURSDAY... A CLOSED LOW TRACKING
NORTHEAST ALONG THE GREAT BASIN WILL BRING SHOWERS THROUGHOUT THE
AREA ON SUNDAY AFTERNOON/EVENING. ENSEMBLE SURFACE-BASED CAPE
(SBCAPE) AND LAPSE RATE GUIDANCES GENERALLY FAVOR A 20-30% CHANCE OF
THUNDERSTORMS SUNDAY AFTERNOON, PRIMARILY ALONG THE SOUTHWEST ID AND
ID/OR BORDER AREAS. SUNDAY AND MONDAY WILL SEE BREEZY CONDITIONS AS
THE CLOSED LOW MOVES OUT. A BRIEF RIDGE WILL BUILD INTO THE AREA
MONDAY THROUGH TUESDAY, BRINGING DRY CONDITIONS. A WEAKER SHORTWAVE
TROUGH WILL BRING A 20-50% CHANCE OF PRECIPITATION TO HIGHER
ELEVATIONS THROUGH THE LATE HOURS OF TUESDAY. A STRONG RIDGE
BUILDING INTO THE NORTHWEST REGION WILL RETURN DRIER AND WARMER
CONDITIONS WEDNESDAY AND THURSDAY.
TEMPERATURES WILL GENERALLY FOLLOW A WARMING TREND, WITH VALLEY
DAYTIME TEMPERATURES GENERALLY IN THE UPPER 60S/LOWER 70S SUNDAY
THROUGH TUESDAY AND CLIMBING INTO THE LOWER TO UPPER 70S WEDNESDAY
THROUGH THURSDAY. SNOW LEVELS ARE EXPECTED TO RISE FROM 6-7 KFT TO 8-
9 KFT SUNDAY TO THURSDAY, FAVORING MINIMAL SNOW ACCUMULATIONS
CONFINED TO THE HIGHEST ELEVATIONS.
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
DISCUSSION...BW
AVIATION.....BW
SHORT TERM...JDS
LONG TERM....JY
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