107
FXUS65 KBOI 041122
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
522 AM MDT MON MAY 4 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES INTO NEXT WEEKEND.
- ISOLATED PM SHOWERS AND THUNDERSTORMS THROUGH TUESDAY, MOSTLY
ALONG THE NV BORDER AND ACROSS SOUTH-CENTRAL IDAHO.
- WINDY MONDAY AND TUESDAY AFTERNOON, ESPECIALLY IN SOUTHEAST
OREGON AND THE SNAKE BASIN IN IDAHO.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED 346 AM MDT MON MAY 4 2026
INTERESTING PATTERN OVER THE REGION, WITH A HIGH-OVER-LOW ALONG
THE WEST COAST AND DEEPENING TROUGH EAST OF THE CONTINENTAL
DIVIDE. OUR REGION WILL REMAIN ON THE EDGE OF/IN-BETWEEN THESE
FEATURES. MOISTURE ALOFT WILL CONTINUE TO CONVERGE ALONG THE
NORTHERN NV BORDER AS SOUTHERLY FLOW AROUND THE LOW MEETS A
STRENGTHENING NORTHERLY FLOW ASSOCIATED WITH THE NORTHERN HIGH
AND DEEPENING TROUGH. FORECASTS HAVE BEEN TRENDING TOWARD THE
DRIER NORTHERLY FLOW WINNING THIS BATTLE, WHICH IS SUPPORTED BY
OVERNIGHT WATER VAPOR SATELLITE IMAGERY. THE RESULT IS A LOWER
CHANCE OF PRECIPITATION (15-25%) FROM THE ID/NV BORDER THROUGH
THE WESTERN MAGIC VALLEY AND BOISE MTNS FOR TODAY. WHILE CUMULUS
BUILDUPS AND AN ISOLATED SHOWER/STORM COULD BE SEEN FURTHER
NORTH AND WEST, THE DRY AIR AND MID-LEVEL WARMING FROM THE
NORTHERN HIGH WILL LIKELY BE TOO MUCH, ESPECIALLY WEST OF THE
ID/OR LINE. GUSTY WINDS AND BRIEF HEAVY RAIN ARE POSSIBLE FROM
STORMS THAT DEVELOP. OUTSIDE OF SHOWERS/STORMS NORTHERLY WINDS
WILL RAMP UP THIS AFTERNOON, THEN MORE SO ON TUESDAY AS
WIDESPREAD GUSTS OF 30-40 MPH SET IN. THE PROLONGED PERIOD OF
GUSTY WINDS COULD BRING BLOWING DUST TO SE OREGON AND PORTIONS
OF THE SNAKE PLAIN. WEDNESDAY IS DRY AND LESS WINDY AS THE
NORTHERN HIGH EXPANDS ACROSS THE WEST. TUESDAY AND WEDNESDAY ARE
THE COOLEST DAYS OF THE WEEK, WITH HIGH TEMPERATURES DROPPING
TO WITHIN 5-10 DEGREES OF NORMAL.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED 346 AM MDT MON MAY 4 2026
THE UPPER-LEVEL RIDGE BUILDING INTO THE WESTERN U.S. WILL
CONTINUE TO MOVE OVERHEAD THURSDAY INTO MIDDAY FRIDAY,
PROVIDING MOSTLY DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES.
AN UPPER-LEVEL SHORTWAVE WILL DISRUPT THIS BRIEFLY FRIDAY PM
INTO SATURDAY, MOVING EAST/SOUTHEAST THROUGH THE SOUTHERN
CANADIAN PROVINCES / PACIFIC NW INTO THE INTERMOUNTAIN WEST AND
LEE SIDE OF THE ROCKIES. THIS WILL CAUSE CLOUDIER SKIES,
PRECIPITATION CHANCES (10-20% CHANCE OF SHOWERS OVER HIGH
TERRAIN IN SOUTHWEST IDAHO AND SOUTHEAST OREGON), AND STILL
ABOVE NORMAL (BUT SLIGHTLY COOLER COMPARED TO THURSDAY)
TEMPERATURES. ONCE THIS FEATURE MOVES FURTHER EAST/SOUTHEAST
LATE SATURDAY, ANOTHER UPPER-LEVEL RIDGE BUILDS IN OVER THE
WESTERN U.S., WITH THIS LASTING INTO AT LEAST EARLY THE NEXT
WEEK. SOME CLUSTERS / ENSEMBLES HAVE THIS UPPER-LEVEL RIDGE AS
PARTICULARLY INTENSE, ENABLING THE POTENTIAL FOR THE LOWER SNAKE
RIVER PLAIN TEMPERATURES TO REACH THE UPPER 80S AND POSSIBLY
EVEN 90F (10-20% CHANCE IN THE BOISE AREA OF 90+F).
AVIATION /12Z MONDAY THROUGH TUESDAY/
ISSUED 520 AM MDT MON MAY 4 2026
VFR WITH WITH MOSTLY CLEAR SKIES THROUGH MORNING. PATCHY VALLEY
SMOKE IN THE BOISE MOUNTAINS. ISOLATED SHOWERS/THUNDERSTORMS
WILL RETURN MAINLY OVER NV BORDER AND HIGH TERRAIN OF SW ID IN
THE AFTERNOON/EVENING. SURFACE WINDS: VARIABLE UP TO 10 KT
THROUGH MORNING, BECOMING W-NW 10-20 KT WITH GUSTS TO 25 KT IN
THE AFTERNOON. WINDS ALOFT AT 10K FT MSL: NW-NE 10-20 KT.
KBOI...VFR WITH CLEAR SKIES. SURFACE WINDS: VARIABLE LESS THAN 7
KT THROUGH MORNING, BECOMING NW 8-13 KT WITH GUSTS UP TO 20 KT
IN THE AFTERNOON.
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.....CH
SHORT TERM...DG
LONG TERM....CH
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