546
FXUS65 KBOI 251534
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
934 AM MDT FRI APR 25 2025
DISCUSSION
PACIFIC UPPER LOW, CENTERED 39N/131W AT 9 AM MDT,
WILL CIRCULATE MOIST, UNSTABLE AIR INTO OUR CWA FROM THE SOUTH
TODAY, WITH A DISTINCT SHORT WAVE TROUGH PASSING THROUGH OUR
CWA THIS EVENING. THE SHORT WAVE WILL ENHANCE THE SHOWERS (50
TO 70 PERCENT AREAL COVERAGE), AND HI-RES MODELS SHOW ISOLATED
THUNDERSTORMS (20 PERCENT COVERAGE) MOVING NNW-WARD THROUGH OUR
CWA THIS EVENING. SIGNIFICANT CAPE (NEAR 600 J/KG) ALONG WITH
INITIAL LOW-LEVEL DRYNESS WILL GENERATE WIND GUSTS TO 50 MPH
WITH THUNDERSTORMS. SATURDAY SHOULD HAVE FEWER STORMS WITH NO
STRONG SHORT WAVE TROUGH INDICATED, BUT SUNDAY LOOKS STORMY
AGAIN AS THE PACIFIC UPPER LOW COMES INLAND ACROSS NORTHERN
CALIFORNIA INTO NEVADA. BY THEN THE LOWER LEVELS WILL BE MORE
MOIST, RESULTING IN MORE NUMEROUS SHOWERS AND WEAKER BUT ALSO
MORE NUMEROUS THUNDERSTORMS. CURRENT FORECAST COVERS ALL THIS.
NO UPDATES FOR NOW.
AVIATION
VFR. SCATTERED SHOWERS AND ISOLATED (10-20%) OF
THUNDER IN THE AFTERNOON OVER THE WEST-CENTRAL & BOISE MTNS AND
NEAR KMYL. SURFACE WINDS: VARIABLE 5-15 KT, THEN E-SE 5-15 KT
THROUGH EVENING/OVERNIGHT. WINDS ALOFT AT 10KFT: SW 10-20 KT
BECOMING S-SW 15-30 KT TONIGHT.
KBOI...VFR. VARIABLE UNDER 5 THIS MORNING BECOMING NW UP TO 10 KT
MIDDAY AND AFTERNOON. SHIFTING TO E-SE LESS THAN 10 KT THROUGH
EVENING/ OVERNIGHT. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS THIS EVENING.
WEEKEND OUTLOOK...VFR. ACTIVE WEATHER THROUGH THE WEEKEND, WITH
CHANCES OF SHOWERS AND SLIGHT CHANCES OF AFTERNOON THUNDERSTORMS
THROUGHOUT THE AREA FRIDAY-SUNDAY. SHOWERS/THUNDERSTORMS MAY
RESULT IN MVFR CONDITIONS, MOUNTAIN OBSCURATION, AND PRODUCE
GUSTY OUTFLOWS. WINDS INCREASING THROUGH SUNDAY, WITH GUSTS UP
TO 30 KT SUNDAY AFTERNOON.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH SUNDAY NIGHT...AN UPPER LEVEL LOW
WILL MOVE ONTO THE COAST OF NORTHERN CA TODAY, THEN MOVE EAST
ACROSS NV SATURDAY INTO SUNDAY. MOISTURE ADVECTION AND UPPER
LEVEL DIFFLUENCE WILL INCREASE AND THEN REMAIN HIGH THROUGH
THE WEEKEND. INSTABILITY WILL INCREASE OVER MOST OF THE AREA,
BRINGING WITH IT A SLIGHT CHANCE OF THUNDERSTORMS. CAPE VALUES
UP TO 600 J/KG WILL DEVELOP TODAY - INITIALLY IN THE SOUTH BUT
THEN SPREADING TO MOST AREAS THIS EVENING. SATURDAY, THE BEST
INSTABILITY WILL BE OVER THE NORTH AND WEST. AS THE UPPER LOW
MOVES INTO UTAH SUNDAY, THE BEST INSTABILITY WILL SHIFT EAST
WITH IT. THUNDERSTORMS MAY CONTAIN SMALL HAIL, AND WILL HAVE
THE POTENTIAL FOR WIND GUSTS TO 50 MPH TODAY, AND 45 MPH
SATURDAY AND SUNDAY. BRIEF TORRENTIAL RAINFALL IS ALSO POSSIBLE.
TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE NORMAL TODAY AND
SATURDAY, COOLING TO NEAR NORMAL SUNDAY. ASIDE FROM WIND GUSTS
ASSOCIATED WITH STRONG SHOWERS AND THUNDERSTORMS, EASTERLY WIND
GUSTS TO 25 MPH ARE LIKELY IN/NEAR THE WESTERN MAGIC VALLEY AND
CAMAS PRAIRIE TODAY. SUNDAY, NORTHWEST WINDS WILL GUST 25 TO 40
MPH IN EASTERN OREGON, AND 15 TO 30 MPH OVER MOST OF SW IDAHO,
AS A COLD FRONT MOVES THROUGH.
LONG TERM...MONDAY THROUGH FRIDAY...RIDGING ALOFT WILL BUILD IN
AS THE UPPER LOW MOVES FARTHER AWAY TO THE SE MONDAY, BRINGING
DRY AND SEASONABLE WEATHER. A SHORTWAVE TROUGH WILL MOVE IN
QUICKLY TUESDAY, BRINGING A 20-60% CHANCE OF SHOWERS (HIGHEST
IN THE NORTH). YET ANOTHER RIDGE IS FAVORED WEDNESDAY AND
THURSDAY, SO WE SHOULD BE DRY AND TEMPS WILL WARM UP TO A FEW
DEGREES ABOVE NORMAL WEDNESDAY AND AS MUCH AS 10 DEGREES ABOVE
NORMAL THURSDAY. ALTHOUGH MODEL CONFIDENCE DECREASES BY DAY 7
AS USUAL, ENSEMBLES FAVOR A TROUGH FORMING TO OUR WEST THURSDAY
INTO FRIDAY, PUTTING OUR AREA IN WARM SW FLOW ALOFT AND LIKELY
INCREASING MOISTURE AT MID AND HIGH LEVELS. THEREFORE, WE HAVE
INTRODUCED A CHANCE OF SHOWERS FRIDAY. TEMPS ARE FORECAST TO BE
10-15 DEGREES ABOVE NORMAL (NEAR 80 IN LOWER ELEVATIONS) FRIDAY.
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...LC
AVIATION.....JY
SHORT TERM...SP
LONG TERM....SP
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