235
FXUS65 KBOI 190848
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
248 AM MDT TUE MAY 19 2026
KEY MESSAGES
- FROST ADVISORY FOR THE WESTERN MAGIC VALLEY UNTIL 8 AM MDT
THIS MORNING.
- WARMING TREND AND CONTINUED GENERALLY DRY THE REST OF THE
WEEK. MONDAY SHOULD BE THE WARMEST DAY.
- COLD FRONT EARLY TUESDAY, THEN WINDY AND TURNING COOLER WITH
A CHANCE OF SHOWERS AND THUNDERSTORMS.
SHORT TERM /THROUGH THURSDAY NIGHT/
PATCHY FROST THIS MORNING IN THE WESTERN MAGIC VALLEY BUT WEDNESDAY
MORNING WILL BE MILDER WITH NO FROST. GRADUAL WARMING TREND TODAY
THROUGH THURSDAY AS THE MAIN UPPER TROUGH SHIFTS EAST OF THE
CONTINENTAL DIVIDE. HOWEVER, ANOTHER WEAKER UPPER TROUGH, IN BC
EARLY THIS MORNING, WILL DIG SOUTHWARD INTO EASTERN ID WEDNESDAY
AND LIMIT THE WARMING IN OUR AREA. THIS SECOND TROUGH WILL BE
CLOSE ENOUGH TO OUR CWA FOR A SLIGHT CHANCE OF SHOWERS IN
EASTERN VALLEY COUNTY WEDNESDAY EVENING, AND ALSO SLIGHTLY
STRONGER WIND IN THE MAGIC VALLEY WEDNESDAY AFTERNOON. OTHERWISE,
NO EVENTFUL WEATHER THROUGH THURSDAY NIGHT.
LONG TERM /FRIDAY THROUGH TUESDAY/
A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE WESTERN US BY THE END
OF THIS WEEK, BRINGING GENERALLY WARM AND DRY CONDITIONS TO THE
REGION THROUGH MONDAY. TEMPERATURES WILL BE ABOUT 10-15 DEGREES
ABOVE NORMAL. ON SATURDAY, A QUICK MOVING SHORTWAVE TROUGH WILL MOVE
THROUGH THE REGION BRINGING LOW CHANCES OF SHOWERS AND THUNDERSTORMS
(<10% CHANCE) OVER HIGH TERRAIN IN SOUTHWEST IDAHO AND THE OR-NV
BORDER. THE RIDGE WILL REACH PEAK STRENGTH ON SUNDAY, WITH HIGH
TEMPERATURES NEAR 90F IN THE TREASURE VALLEY. BY MONDAY, THERE IS
WIDESPREAD MODEL AGREEMENT IN A DEEP UPPER LEVEL LOW MOVING INTO
THE PACIFIC NORTHWEST. THE LOW WILL THEN MOVE INTO THE REGION
ON TUESDAY, COOLING TEMPERATURES OFF BY 10-20 DEGREES AND
BRINGING BREEZY WINDS WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
(20-30% CHANCE).
AVIATION /06Z TUESDAY THROUGH WEDNESDAY/
ISSUED 1206 AM MDT TUE MAY 19 2026
VFR. VIRGA/ISOLATED SHOWERS RE-DEVELOPING TUESDAY AFTERNOON OVER
HIGH TERRAIN, MAINLY THE NORTHEAST OR/CENTRAL ID MTNS. SURFACE
WINDS: VARIABLE 5-10 KT OVERNIGHT, THEN SW-NW 5-15 KT TUE AFTERNOON.
WINDS ALOFT AT 10KFT MSL: TRANSITIONING FROM NW TO W, 5-15 KT.
KBOI...VFR. SURFACE WINDS: LIGHT AND VARIABLE THROUGH THE MORNING.
THEN, NW 5-10 KT TUE AFTERNOON WITH OCCASIONAL GUSTS AROUND 15 KT.
BOI WATCHES/WARNINGS/ADVISORIES
ID...FROST ADVISORY UNTIL 8 AM MDT THIS MORNING FOR IDZ016.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...LC
LONG TERM....SA
AVIATION.....SA
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