268
FXUS65 KBOI 311557
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
957 AM MDT MON MAR 31 2025
DISCUSSION
SHOWERS THIS MORNING WILL EXPAND IN COVERAGE AND
INTENSITY DUE TO A COMBINATION OF DAYTIME HEATING AND UPPER
LEVEL SUPPORT FROM A SHORT WAVE MOVING THROUGH LATER TODAY. HI-
RES MODELS CONTINUE TO INDICATE ISOLATED THUNDERSTORMS, WITH
THE POTENTIAL FOR GUSTY WINDS, SMALL HAIL, AND HEAVY RAIN. SNOW
LEVELS AVERAGE 4000-5000 FEET, SO THE HEAVIER SHOWERS/T-STORMS
COULD DROP LOCALLY HEAVY SNOWFALL IN A SHORT TIME. NO UPDATES
FOR NOW.
AVIATION
MAINLY VFR. NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS THROUGH THE AFTERNOON, WITH COVERAGE DECREASING
AFTER 01/02. SNOW LEVELS 4-5KFT. PERIODS OF MVFR CONDITIONS IN
RAIN WITH MVFR/IFR IN SNOW. MOUNTAINS OBSCURED AT TIMES. SURFACE
WINDS: SW-NW 10-20 KT WITH GUSTS 25-35 KT THIS AFTERNOON BEHIND
THE FRONT. WINDS ALOFT AT 10KFT: SW 25-45 KT.
KBOI...MAINLY VFR. NUMEROUS SHOWERS RESULTING IN LOW VFR
CEILINGS. 20% CHANCE OF THUNDERSTORMS THROUGH 01/02Z. SURFACE
WINDS: SE 5-15 KT, BECOMING NW 5-15 KT WITH GUSTS TO 25 KT.
BRIEF GUSTS TO 35 KT POSSIBLE IF WE GET A THUNDERSTORM CLOSE BY.
HYDROLOGY
COLD, SHOWERY CONDITIONS WILL PERSIST THROUGH
TUESDAY, WITH SNOW LEVELS REMAINING LOW. WHILE WIDESPREAD HEAVY
PRECIPITATION IS NOT EXPECTED, SOME OF THE FORECASTED
PRECIPITATION TODAY AND TUESDAY MAY FALL AS SNOW. MINOR FLOODING
IS EXPECTED TO CONTINUE ALONG THE SILVIES RIVER NEAR BURNS AND
THE MALHEUR RIVER NEAR VALE THROUGH MIDWEEK. HOWEVER, BOTH
RIVERS ARE TRENDING DOWNWARD DUE TO COLDER TEMPERATURES, WHICH
ARE EXPECTED TO PERSIST THROUGH FRIDAY.
WARMER TEMPERATURES ARE FORECAST TO RETURN NEXT WEEKEND,
POTENTIALLY INCREASING HIGH-ELEVATION SNOWMELT AND COULD LEAD TO
RENEWED RISES IN RIVER LEVELS.
PREV DISCUSSION
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS CONTINUE ACROSS SOUTHWEST IDAHO THIS
MORNING, SUPPORTED BY BROAD DIFFLUENCE AND COLD AIR ALOFT.
THESE SHOWERS AND STORMS WILL TRACK NORTHEAST INTO THE CENTRAL
IDAHO MOUNTAINS, PERSISTING THROUGH 6 AM MDT.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP LATER THIS
MORNING AHEAD AND ALONG AN APPROACHING COLD FRONT. FURTHER
DESTABILIZATION IS EXPECTED AS MUCH COLDER AIR MOVES IN ALOFT,
INCREASING INSTABILITY AND SHEAR. THIS WILL SUPPORT STRONGER
SHOWERS AND THUNDERSTORMS, LIKELY FORMING JUST AHEAD OF THE
SURFACE FRONT, BEGINNING AROUND 10 AM MDT IN SOUTHEAST OREGON
AND REACHING SOUTHWEST IDAHO JUST BEFORE NOON. THE STRONGEST
STORMS MAY PRODUCE GRAUPEL OR SMALL HAIL, HEAVY RAIN, AND WIND
GUSTS UP TO 45 MPH. SNOW LEVELS WILL RANGE FROM 4,500 TO 5,500
FEET MSL, WITH LIGHT SNOWFALL EXPECTED IN MOUNTAIN VALLEYS,
ACCUMULATING UP TO 4 INCHES. HIGHER ELEVATIONS ABOVE 6,500 FEET
COULD SEE UP TO 6 INCHES OF NEW SNOW AS THE FRONT MOVES THROUGH.
INCREASED MIXING TODAY MAY ALSO LEAD TO MORE WIDESPREAD WIND
GUSTS UP TO 45 MPH, PARTICULARLY WITH FRONTAL PASSAGE.
BY MONDAY EVENING, TEMPERATURES AND SNOW LEVELS WILL DROP TO
AROUND 3,000 FEET. SNOW SHOWERS WILL PERSIST MAINLY SOUTH OF THE
SNAKE RIVER PLAIN INTO TUESDAY MORNING, EXPANDING IN COVERAGE
BY THE AFTERNOON AND EVENING AS AN UPPER-LEVEL LOW REMAINS JUST
TO THE WEST. THERE IS A 20% CHANCE OF A RAIN-SNOW MIX IN LOWER
VALLEYS TUESDAY MORNING, THOUGH SURFACE TEMPERATURES ARE LIKELY
(80% CHANCE) TO REMAIN AT OR JUST ABOVE FREEZING IN THE TREASURE
VALLEY, PREVENTING SNOW ACCUMULATION. THE LOW WILL WEAKEN AS IT
MOVES SOUTHEAST ACROSS CENTRAL OREGON INTO NORTHERN NEVADA ON
TUESDAY. COLD BUT DRIER CONDITIONS ARE EXPECTED WEDNESDAY UNDER
NORTHERLY FLOW ALOFT, WITH ONLY A SLIGHT (20%) CHANCE OF SHOWERS
IN THE CENTRAL IDAHO MOUNTAINS DURING THE AFTERNOON.
HIGH TEMPERATURES WILL BE ABOUT 5 DEGREES BELOW NORMAL TODAY,
DROPPING TO AROUND 10 DEGREES BELOW NORMAL ON TUESDAY.
LONG TERM...THURSDAY THROUGH MONDAY...THE BACKSIDE OF A
LONGWAVE TROUGH WILL CONTINUE TO PUSH OUT EASTWARD THROUGH
THURSDAY, AS A WEAK EMBEDDED SHORTWAVE TROUGH BRIEFLY EXTENDS
THE AREA THROUGH THURSDAY. LOWER PRECIPITATION CHANCES BETWEEN
20-60% WILL REMAIN OVER HIGHER ELEVATIONS THROUGHOUT THURSDAY,
WITH LITTLE TO NO PRECIPITATION EXPECTED ACROSS THE VALLEYS.
SNOW LEVELS ARE EXPECTED TO GENERALLY REMAIN AROUND 2000-3000 FT
UNTIL THE AFTERNOON HOURS OF THURSDAY, FAVORING SOME CHANCE OF
SNOWFALL IN THE MOUNTAINS. SNOW LEVELS WILL THEN INCREASE TO
4000-5000 FT ACROSS MOST AREAS THROUGH FRIDAY INTO THE WEEKEND.
A LARGE RIDGE BUILDING IN ACROSS THE PACIFIC NORTHWEST WILL
SUSTAIN DRY CONDITIONS ACROSS THE AREA THROUGH FRIDAY AND THE
WEEKEND. DAYTIME TEMPERATURES ARE EXPECTED TO RANGE IN THE 50S
AND COOLER NIGHTTIME TEMPERATURES IN THE HIGH 30S TO LOW 40S
UNTIL THE END OF THE EXTENDED FORECAST PERIOD.
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
DISCUSSION...BW
AVIATION.....SP
HYDROLOGY....JDS/BW
SHORT TERM...JDS
LONG TERM....JY
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