477
FXUS65 KBOI 191824
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1224 PM MDT TUE MAY 19 2026
UPDATE
UPDATED AVIATION DISCUSSION.
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/
ISSUED 248 AM MDT TUE MAY 19 2026
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/
ISSUED 248 AM MDT TUE MAY 19 2026
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 /18Z TUESDAY THROUGH WEDNESDAY/
ISSUED 1214 PM MDT TUE MAY 19 2026
VFR. SCATTERED HIGH BASED CUMULUS CLOUDS WILL CONTINUE OVER THE
AREA WITH SOME PRODUCING VIRGA AND GUSTY WINDS. SURFACE WINDS
GENERALLY W TO NW AT 5-15 KTS, EXCEPT IN THE VICINITY OF VIRGA
WHERE GUSTS TO 35 KTS ARE POSSIBLE THIS AFTERNOON. WINDS LIGHT
AND VARIABLE LESS THAN 10 KTS TONIGHT ACROSS THE AREA. WINDS
W-NW 10 TO 15 KTS ON WEDNESDAY.
KBOI...VFR. SURFACE WINDS NW 10 TO 15 KTS THIS AFTERNOON. WINDS
LIGHT AND VARIABLE LESS THAN 5 KTS TONIGHT. WINDS W-NW 10 TO 15
KTS ON WEDNESDAY.
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...JB
SHORT TERM...LC
LONG TERM....SA
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