421
FXUS65 KBOI 070003
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
603 PM MDT MON APR 6 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH TUESDAY.
- A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING ACROSS EAST-CENTRAL OREGON AND WEST-
CENTRAL IDAHO.
- A DRY COLD FRONT ON TUESDAY WILL BRING BREEZY WINDS, WITH
TEMPERATURES COOLING 5-10 DEGREES BY WEDNESDAY.
- A WETTER PATTERN WILL DEVELOP LATE IN THE WEEK INTO THE
WEEKEND.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED 207 PM MDT MON APR 6 2026
THE UPPER LEVEL RIDGE AXIS THAT BROUGHT UNSEASONABLY WARM
TEMPERATURES TO THE REGION WILL SHIFT EAST TONIGHT AS THE NEXT
SYSTEM APPROACHES FROM THE NORTHWEST. LOW TEMPERATURES WILL
REMAIN MILD, GENERALLY IN THE UPPER 30S TO MID 40S IN THE LOWER
VALLEYS.
ON TUESDAY, A MORE POTENT UPPER LEVEL TROUGH WILL MOVE EAST
ACROSS SOUTHERN CANADA, PUSHING A DRY COLD FRONT THROUGH OUR
AREA. WHILE THIS FRONT LACKS SIGNIFICANT MOISTURE, IT WILL
TIGHTEN THE PRESSURE GRADIENT ACROSS THE REGION. NORTHWESTERLY
WIND GUSTS OF 20 TO 35 MPH WILL DEVELOP IN THE AFTERNOON AND
EVENING, WITH STRONGER GUSTS POSSIBLE ON RIDGELINES. THESE
BREEZY WINDS, COMBINED WITH LOWERING RELATIVE HUMIDITY VALUES,
WILL RESULT IN INCREASED FIRE DANGER ACROSS PORTIONS OF
SOUTHEAST OREGON AND SOUTHWEST IDAHO. ADDITIONALLY, WEAK
INSTABILITY AHEAD OF AND ALONG THE FRONT WILL SUPPORT A 20
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. THIS ACTIVITY IS
EXPECTED TO BE FOCUSED MAINLY ALONG THE IDAHO/NEVADA BORDER
DURING THE AFTERNOON AND EVENING HOURS. HIGH TEMPERATURES ON
TUESDAY WILL BE SLIGHTLY COOLER IN THE NORTH, WHILE SOUTHERN
AREAS REMAIN WARM UNTIL THE FRONTAL PASSAGE.
BY WEDNESDAY, TEMPERATURES WILL COOL 5 TO 10 DEGREES AS THE
GRAZING SHORTWAVE EXITS TO THE EAST AND FLOW SWITCHES TO THE
NORTHWEST. WINDS WILL BEGIN TO SUBSIDE BUT REMAIN BREEZY IN THE
AFTERNOON WITH GUSTS OF 15 TO 25 MPH. MOISTURE AHEAD OF AN
APPROACHING LOW OFF THE CALIFORNIA COAST WILL BRING A 20 PERCENT
CHANCE OF SHOWERS TO THE OREGON AND NEVADA BORDER LATE
WEDNESDAY.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED 207 PM MDT MON APR 6 2026
A WARM AND ACTIVE PATTERN WILL ARRIVE IN THE LONG-TERM PERIOD.
OUR AREA WILL BE SET IN BETWEEN TWO SYSTEMS COME THURSDAY, WITH
THE MAIN JET STREAM NORTH AND A CLOSED LOW OFF OF THE COAST OF
CALIFORNIA. SOUTHERLY FLOW ASSOCIATED WITH THE LOW WILL MAINTAIN
TEMPERATURES NEAR 10 DEGREES ABOVE NORMAL. AS THE CALIFORNIA
LOW SLOWLY MOVES EAST, PACIFIC MOISTURE ADVECTING AROUND IT
WILL ALLOW FOR INCREASING CHANCES OF PRECIPITATION. THURSDAY
AFTERNOON, PRECIPITATION CHANCES WILL INCREASE TO 15-35% NEAR
THE IDAHO/NEVADA BORDER AND SOUTHEAST OREGON. COME FRIDAY
AFTERNOON, PRECIPITATION CHANCES INCREASE TO 30-70% NEARLY AREA-
WIDE. WITH AFTERNOON DESTABILIZATION SUPPORTING A 10-15% CHANCE
OF THUNDERSTORMS. SATURDAY APPEARS TO BE THE MOST ACTIVE DAY, AS
THE LOW CONTINUES TO MOVE INLAND, PRECIPITABLE WATER VALUES
INCREASE TO ABOVE THE 90TH PERCENTILE OF CLIMATOLOGY.
PRECIPITATION CHANCES WILL INCREASE TO 40-75% AREA-WIDE. THERE
ARE HINTS OF A SHORTWAVE IN THE MAIN JET STREAM NORTH AS WELL,
WHICH COULD INTERACT WITH THIS MOISTURE AND PROVIDE ADDITIONAL
FORCING FOR ASCENT. THIS PATTERN IS TYPICALLY SUPPORTIVE OF
THUNDERSTORMS. ENSEMBLE GUIDANCE HAS INSTABILITY BUILDING IN
WITH MEAN CAPE VALUES AROUND OF 200-250 J/KG, WHICH WILL
SUPPORTS THE THREAT AS WELL. FOR NOW WILL KEEP THUNDER CHANCES
SATURDAY AFTERNOON 15-20%.
TEMPERATURES WILL COOL DOWN TO NEAR NORMAL COME SUNDAY, AS THE
CALIFORNIA LOW AND REINFORCING SHORTWAVE MAKE THEIR WAY OVER OUR
AREA. PRECIPITATION CHANCES WILL REMAIN ELEVATED (40-75%) THROUGH
SUNDAY AS THE SYSTEM MOVES THROUGH. SNOW LEVELS WILL BE AT 8000+
FT MSL THROUGH THE LONG TERM, DROPPING TO 4500-6500 FT MONDAY.
AVIATION /00Z TUESDAY THROUGH WEDNESDAY/
ISSUED 553 PM MDT MON APR 6 2026
VFR. ISOLATED SHOWERS/THUNDERSTORMS THROUGH TONIGHT IN E-CNTRL
OREGON AND W-CNTRL IDAHO NEAR KBKE/KMYL. LOCALIZED OUTFLOWS TO
25 KT WITH STORM ACTIVITY. SURFACE WINDS: SW-NW 5-15 KT THIS
AFTERNOON BECOMING VARIABLE OVERNIGHT. THEN NW-W 10-20 KT WITH
GUSTS TO 20-30 KT AFTER TUE/16Z. WINDS ALOFT AT 10 KFT MSL: W
10-25 KT.
KBOI...VFR. SURFACE WINDS: NW 5-10 KT, SHIFTING TO S-SE 3-7 KT
AFTER SUNSET. BECOMING NW 10-16 KT WITH GUSTS TO 20-25 KT AFTER
TUE/17Z FOLLOWING A COLD FRONT.
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
AVIATION.....SH
SHORT TERM...JDS
LONG TERM....NF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page