279
FXUS65 KBOI 010257
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
857 PM MDT MON JUN 30 2025
DISCUSSION
A FEW THUNDERSTORMS REMAIN ACTIVE THIS EVENING
ALONG THE IDAHO/NEVADA BORDER, ASSOCIATED WITH A DEEPENING
UPPER- LEVEL TROUGH OFF THE PACIFIC NORTHWEST COAST AND AN
INFLUX OF MIDLEVEL MOISTURE FROM THE SOUTHWESTERN U.S. THUS FAR,
STORMS HAVE BEEN SHORT-LIVED AND PRIMARILY DRIVEN BY SURFACE
HEATING, WITH LIMITED SHEAR ACROSS THE REGION. A PEAK WIND GUST
OF 50 MPH WAS REPORTED EARLIER IN SOUTHWEST OWYHEE COUNTY,
THOUGH MOST STORMS HAVE PRODUCED GUSTS IN THE 30 TO 40 MPH RANGE
AND LITTLE TO NO MEASURABLE PRECIPITATION.
CONVECTION WILL TAPER OFF AFTER SUNSET, BUT ANOTHER ROUND OF
SHOWERS AND ISOLATED THUNDERSTORMS IS EXPECTED TO DEVELOP BY
SUNRISE TUESDAY ACROSS SOUTHEAST OREGON WITH THE APPROACH OF A
WEAK EMBEDDED SHORTWAVE. THE POTENTIAL FOR STRONGER
THUNDERSTORMS INCREASES TUESDAY AFTERNOON (30% CHANCE),
PARTICULARLY ACROSS SOUTH-CENTRAL IDAHO, WHERE MODEST
INSTABILITY (CAPE) AND IMPROVED DEEP-LAYER SHEAR (0–6 KM) WILL
COINCIDE WITH AN ADDITIONAL SHORTWAVE PASSAGE. THE WESTERN MAGIC
VALLEY WILL BE MOST FAVORED FOR STRONG CONVECTION CAPABLE OF
PRODUCING WIND GUSTS UP TO 60 MPH.
AVIATION
MAINLY VFR. ISOLATED SHOWERS AND THUNDERSTORMS THIS
EVENING NEAR THE NV BORDER AND LOWER MAGIC VALLEY WITH GUSTS UP TO
40 KT. HIGH DENSITY ALTITUDE DUE TO HEAT. ADDITIONAL ISOLATED
SHOWERS AND THUNDERSTORMS ON TUESDAY ACROSS SE OREGON AND HIGHER
TERRAIN OF SW IDAHO. SURFACE WINDS: NW-NE 5-15 KT. WINDS ALOFT AT
10KFT MSL: VARIABLE 10 KT OR LESS, BECOMING E-S 10-20 KT THIS
EVENING BY 06Z.
KBOI...VFR. HIGH DENSITY ALTITUDE DUE TO HEAT. SURFACE WINDS: NW 5-
10 KT, BECOMING VARIABLE LESS THAN 8 KT THIS EVENING 04Z AND
AFTER.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...AN UPPER LEVEL
TROUGH REMAINS OFF THE CA COAST WITH UNUSUAL ISOLATED
THUNDERSTORMS OVER THE MARINE LAYER CONTINUING THIS AFTERNOON.
THIS SYSTEM IS BRINGING MID LEVEL MOISTURE AND SMOKE TO THE AREA
FROM THE SOUTH. A 10-20 PERCENT CHANCE OF THUNDERSTORMS IS
FORECAST THIS AFTERNOON ALONG THE NV BORDER AND SOUTH CENTRAL
OR, WHERE CUMULUS CLOUDS ARE BEGINNING TO FORM THIS AFTERNOON.
GUSTY OUTFLOW WINDS UP TO 45 MPH POSSIBLE WITH THE STORMS THIS
AFTERNOON ALONG THE NV BORDER AND WESTERN HARNEY COUNTY.
ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE INTO TUESDAY
MORNING, MAINLY OVER EASTERN OR WITH SPRINKLES POSSIBLE OVER
SOUTHWEST IDAHO. A DRY SLOT WITH THE SYSTEM MOVES INTO
SOUTHEAST OR AND SOUTHWEST ID BY TUESDAY AFTERNOON, LIMITING
THUNDERSTORM THREAT, AND ALLOWING WARMER AIR. TEMPERATURES WILL
BE IN THE LOW 100S IN THE TREASURE VALLEY AND WEISER RIVER BASIN
ON TUESDAY WHERE A HEAT ADVISORY REMAINS IN EFFECT. A SHORTWAVE
MOVES INTO THE PACIFIC NW ON WEDNESDAY, BRINGING A WEAK COLD
FRONT, AND A 20-30 PERCENT CHANCE OF SHOWERS AND STORMS. MAIN
THREATS WITH THE FRONT WILL BE GUSTY WINDS AND GUSTY ERRATIC
OUTFLOW WINDS FROM THUNDERSTORMS UP TO 50 MPH.
LONG TERM...THURSDAY THROUGH MONDAY...FORECAST CONFIDENCE
BEYOND THURSDAY IS LOW. BUT THE MODELS BRING IN SHORTWAVES AT
DIFFERENT TIMES DURING THE THURSDAY TO FRIDAY WINDOW KEEPING A
THREAT OF SHOWERS AND THUNDERSTORMS OVER THE AREA THROUGH
SATURDAY. WITH THOSE SYSTEMS, TEMPERATURES LOWER TO NEAR NORMAL
BY FRIDAY AND CONTINUE THROUGH SUNDAY BEFORE WARMING 5-10
DEGREES BY MONDAY. GUSTY OUTFLOW WINDS WILL BE THE MAIN THREATS
WITH THE THUNDERSTORMS.
BOI WATCHES/WARNINGS/ADVISORIES
ID...HEAT ADVISORY FROM 11 AM TO 8 PM MDT TUESDAY IDZ012-014-033.
OR...HEAT ADVISORY FROM 11 AM MDT /10 AM PDT/ TO 8 PM MDT /7 PM
PDT/ TUESDAY ORZ064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...JDS
AVIATION.....JY
SHORT TERM...KA
LONG TERM....KA
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