815
FXUS65 KBOI 131218
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
608 AM MDT MON APR 13 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW ABOVE 4500 FEET ON MONDAY.
- MUCH COOLER TEMPERATURES WITH RAIN AND SNOW SHOWERS WEDNESDAY
THROUGH FRIDAY.
- SNOW LEVELS WILL DROP TO NEAR VALLEY FLOORS THURSDAY MORNING, WITH
WIDESPREAD LOWER ELEVATION LIGHT SNOW LIKELY.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
WRAPAROUND MOISTURE IS FILLING IN ACROSS THE REGION, WITH RAIN BELOW
ABOUT 5500 FEET. NEARLY 1 INCH OF RAIN FELL ON SUNDAY ACROSS THE
REGION, WITH MANY LOCATIONS OVERACHIEVING SIGNIFICANTLY ON
PRECIPITATION AMOUNTS. AS AIR CONTINUES TO COOL OVERNIGHT, SNOW
LEVELS WILL DROP TO 4500 FEET BY THE EARLY MORNING, WITH ABOUT 1-3
INCHES OF SNOW EXPECTED NEAR MCCALL, ID AND IDAHO CITY, ID. THIS
SNOW WILL LIKELY MELT QUICKLY, AS HIGHS ACROSS THE MOUNTAIN VALLEYS
INCREASE TO THE MID 40S BY LATE MORNING. VALLEY RAIN AND MOUNTAIN
SNOW WILL CONTINUE GENERALLY NORTH OF MOUNTAIN HOME, ID OVERNIGHT
INTO MID MORNING, WITH BREEZY SOUTHWESTERLY WINDS ACCOMPANYING THE
PRECIPITATION. THE WRAPAROUND MOISTURE AND LOW CENTER WILL MOVE EAST
BY MONDAY AFTERNOON, WITH PRECIPITATION GENERALLY TAPERING OFF BY
EARLY AFTERNOON. GRAUPEL SHOWERS AND A STRAY THUNDERSTORM WILL FORM
OVER OVER SOUTHEAST OREGON BY EARLY AFTERNOON, MOVING INTO SOUTHWEST
IDAHO AND LESSENING IN COVERAGE BY EARLY EVENING. CLEARING MONDAY
NIGHT INTO TUESDAY MORNING WILL ALLOW FOR FOG FORMATION ACROSS AREA
VALLEYS, ESPECIALLY IN HIGHER TERRAIN.
DRY CONDITIONS WILL CONTINUE ON TUESDAY AS COOL NORTHWESTERLY FLOW
ALOFT MOVES IN. A VERY COLD LOW PRESSURE SYSTEM WILL THEN MOVE INTO
THE PACIFIC NORTHWEST ON WEDNESDAY, BRINGING A ROBUST COLD FRONT TO
THE REGION ON WEDNESDAY EVENING. GUSTY WINDS, ISOLATED
THUNDERSTORMS, AND ANOTHER PUSH OF WIDESPREAD PRECIPITATION WILL
ACCOMPANY THIS FRONTAL PASSAGE. TEMPERATURES WILL DROP TO BELOW
FREEZING BY WEDNESDAY NIGHT, WITH MOST HIGHER ELEVATION LOCATIONS
CHANGING FROM RAIN TO SNOW BY EARLY EVENING.
LONG TERM /THURSDAY THROUGH MONDAY/
A COLD FRONT WILL CONTINUE TO EXIT OUR AREA THROUGH FRIDAY, USHERING
IN A COLDER AIR MASS AND GUSTY WEST/NORTHWEST WINDS. WHILE
WIDESPREAD PRECIPITATION WILL TAPER OFF, COLDER AIR ALOFT WILL ALLOW
FOR SCATTERED SHOWERS TO DEVELOP ACROSS THE AREA. DEPENDING ON THE
EXACT LOW TRACK, THE WEST CENTRAL MOUNTAINS COULD SEE PERSISTENT
ADDITIONAL PRECIPITATION ON THURSDAY WITH THE DEFORMATION ZONE OF
THE LOW OVERHEAD. SNOW LEVELS WILL DROP TO VALLEY FLOORS ON THURSDAY
BEHIND THIS FRONT. LOW SNOW LEVELS, COMBINED WITH DIURNAL
INSTABILITY, WILL SUPPORT SNOW/WINTRY MIX AND GRAUPEL SHOWERS AREA-
WIDE. ADDITIONAL SNOWFALL AMOUNTS OF UP TO 4 INCHES ARE EXPECTED
ABOVE 4500 FT MSL THURSDAY. SOUTHERN PORTIONS OF THE WESTERN MAGIC
VALLEY HAVE A 40-50% CHANCE OF SEEING AT LEAST A HALF INCH OF
SNOWFALL. ELSEWHERE, LITTLE TO NO ACCUMULATIONS ARE EXPECTED. WINDS
THURSDAY AFTERNOON WILL GUST TO 25-45 MPH, WITH THE STRONGEST GUSTS
IN THE TYPICAL AREAS EAST OF MOUNTAIN HOME AND IN THE CAMAS PRAIRIE.
TEMPERATURES THURSDAY MORNING WILL BE NEAR FREEZING THROUGHOUT THE
SNAKE PLAIN, WITH WIDESPREAD TEMPERATURES AT OR BELOW FREEZING COME
FRIDAY MORNING. FOR THOSE WHO STARTED THEIR GARDEN EARLY, IT MAY BE
GOOD TO CONSIDER COVERING UP PLANTS OR BRINGING THEM INSIDE.
PRECIPITATION CHANCES AND WINDS WILL TAPER OFF FRIDAY, AS THE SYSTEM
EXITS OUR AREA TO THE EAST. THIS WILL ALSO MARK THE START OF A
WARMING TREND, WITH TEMPERATURES BACK UP TO NEAR NORMAL BY SATURDAY
AS A RIDGE BEGINS TO BUILD IN. BY SUNDAY, TEMPERATURES WILL WARM TO
5-10 DEGREES ABOVE NORMAL. CONFIDENCE IS INCREASING ON ANOTHER
SYSTEM DIGGING DOWN FROM THE GULF OF ALASKA EARLY NEXT WEEK. WHILE
EXACT TIMING IS UNCERTAIN, THIS WILL LEAD TO INCREASING
PRECIPITATION CHANCES SUNDAY AFTERNOON, REMAINING ELEVATED (30-60%)
THROUGH MONDAY.
AVIATION /06Z MONDAY THROUGH TUESDAY/
ISSUED 606 AM MDT MON APR 13 2026
WIDESPREAD SHOWERS RESULTING IN LOW VFR/IFR IN RAIN AND IFR/LIFR IN
SNOW. MTNS OBSCURED. SHOWERS BECOMING SCATTERED MON/PM, TAPERING OFF
BY EARLY TUE/AM. ISOLATED THUNDERSTORMS AFTER MON/18Z. SNOW LEVELS:
4500-5000 FT THIS MORNING, RISING TO 5500-6000 FT MON/PM. SURFACE
WINDS: W-NW 5-15 KT WITH GUSTS TO 20-25 KT, BECOMING VARIABLE UP TO
10 KT OVERNIGHT. WINDS ALOFT AT 10KFT MSL: NW-SW 15-30KT.
KBOI...RAIN CONTINUING THROUGH THE MORNING, SHOWERS BECOMING
SCATTERED. SHOWERS BECOMING SCATTERED LATE MON AFTERNOON. SLIGHT
CHANCE OF FOG/LOW STRATUS MON NIGHT/TUE AM. SURFACE WINDS: VARIABLE
OR SE 5-10 KT, TRANSITIONING TO SW-NW 5-15 KT MID MONDAY MORNING.
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.....NF
SHORT TERM...SA
LONG TERM....NF
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