268
FXUS65 KBOI 212026
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
ISSUED BY NATIONAL WEATHER SERVICE POCATELLO ID
226 PM MDT MON APR 21 2025
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
AN UPPER LEVEL
TROUGH TO OUR NORTH WILL GRADUALLY SHIFT EAST ON TUESDAY WHILE
ANOTHER WEAK TROUGH DROPS INTO WESTERN OREGON AND WASHINGTON
LATE TUESDAY INTO WEDNESDAY. TEMPERATURES WILL WARM SEVERAL
DEGREES IN RESPONSE TO THE DEPARTING TROUGH ON TUESDAY, WITH AN
INCREASE IN SOUTHERLY FLOW BRINGING TEMPERATURES UP A COUPLE
MORE DEGREES ON WEDNESDAY AND RESULTING IN TEMPERATURES AROUND
5 DEGREES ABOVE NORMAL. SKIES WILL BE MOSTLY CLEAR TONIGHT,
ALLOWING TEMPERATURES TO DROP INTO THE 20S IN THE MOUNTAINS AND
30S IN THE VALLEYS. CLOUDS WILL INCREASE TUESDAY AND WEDNESDAY
AHEAD OF THE TROUGH. ENOUGH MOISTURE WILL MOVE INTO SOUTHWEST
IDAHO ON WEDNESDAY FOR A 20-30% CHANCE OF SHOWERS AND 10% CHANCE
OF THUNDERSTORMS ACROSS THE CENTRAL IDAHO MOUNTAINS AND
SOUTHERN HIGHLANDS WHILE OTHER AREAS SHOULD REMAIN DRY.
AFTERNOON WINDS WILL BE BREEZY WITH GUSTS 15-25 MPH.
LONG TERM...THURSDAY THROUGH MONDAY
WARM, DRY, AND
COMFORTABLE THURSDAY AND FRIDAY WITH TEMPS 10 DEGREES HIGHER
THAN TODAY (VALLEYS HIGH 60S/LOW 70S, HIGHER ELEVATIONS HIGH
50S/MID 60S). LATE FRIDAY, THE UPPER-LEVEL RIDGE WILL MOVE OFF
TO THE EAST, WITH A VERTICALLY STACKED UPPER-LEVEL LOW PRESSURE
SYSTEM AND LARGE AMPLITUDE LONGWAVE TROUGH MOVING ONSHORE IN THE
PNW LATE FRIDAY INTO SATURDAY. THIS WILL BRING WINDS AT 500 MB
TO BE S/SE AS WELL AS SURFACE WINDS WILL BE S/SE FOR A SHORT
TIME FRIDAY. GFS/ECMWF DO NOT AGREE ON FRONT TIMING, LOOKING TO
BE SOMETIME LATE AFTERNOON FRIDAY FOR SE OR AND EARLY SATURDAY
MORNING FOR SW ID. ONCE THE FRONT STARTS TO MOVE IN,
PRECIPITATION CHANCES STICK AROUND THROUGH THE EXTENDED.
PRECIPITATION CHANCES GENERALLY REMAIN AROUND 20-40% WITH
PERIODS IN HIGHER ELEVATIONS RAISING TO 50-70%. BOTH THE
ECMWF/GFS HAVE NOTEABLE CAPE VALUES FRIDAY AND SATURDAY AS WELL,
WITH THE NBM GIVING 15-20% POTENTIAL FOR THUNDERSTORMS FRIDAY
AND SATURDAY AFTERNOON. WITH UNCERTAINTY OF THE SURFACE LOW
PRESSURE SYSTEM REMAINING QUITE LOW, NO QPF NUMBERS WILL BE
GIVEN AT THIS TIME.
AVIATION
VFR. LOW CLOUDS AND GUSTY WINDS DECREASING DURING
THE EVENING TRANSITION. OVERNIGHT, WEAK AND MOSTLY VARIABLE
WINDS. SNOW LEVELS: 5-6.5 KFT MSL DECREASING TO 3.5-5 KFT.
SURFACE WINDS: W/NW 5- 10 KT GUSTING 15 KTS; MAGIC VALLEY AND
SE TREASURE VALLEY TO SEE W/NW 10-20 GUSTING 20-30 KT. BECOMING
VARIABLE UNDER 10 KT TONIGHT.
KBOI...VFR. SURFACE WINDS W-NW 8-12 KT, GUSTING TO 15-20 KT
THIS AFTERNOON. THIS EVENING, WINDS DECREASING TO UNDER 7 KTS
AND VARIABLE.
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...ST
LONG TERM....CH
AVIATION.....CH
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