154
FXUS65 KBOI 300240
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
823 PM MDT SAT MAR 29 2025
DISCUSSION
TODAY PROVED COLDER THAN FORECAST WITH AN UPPER
LOW AND WIDESPREAD CLOUDS AND SHOWERS DIRECTLY OVER OUR CWA.
SUNDAY LOOKS 8 TO 12 DEGREES WARMER AS THE LOW SHIFTS EAST AND
IS REPLACED BY A PACIFIC UPPER RIDGE, AND BRINGS CLEARER SKIES
THAN TODAY AT LEAST ON THE IDAHO SIDE. CLOUDS WILL INCREASE IN
OREGON, HOWEVER, AS THE NEXT PACIFIC TROUGH MOVES INLAND, WITH
LIGHT RAIN BY LATE AFTERNOON AHEAD OF A WARM FRONT. LIGHT RAIN
WITH BREEZY SOUTHEAST WINDS, AND A 15-20 PERCENT CHANCE OF
THUNDERSTORMS, WILL SPREAD INTO WESTERN IDAHO SUNDAY EVENING,
WITH SNOW LEVEL RISING TO 6000 FEET MSL OR ABOUT 1500 FEET
HIGHER THAN TODAY. THE FOLLOWING COLD FRONT WILL BRING NUMEROUS
RAIN AND SNOW SHOWERS MONDAY MORNING, WITH SNOW LEVEL LOWERING
AGAIN TO 3500-4000 FEET MSL, AND SEVERAL INCHES NEW SNOW TO THE
MOUNTAINS, ESPECIALLY IN IDAHO NORTH OF THE SNAKE BASIN.
COOLING ALOFT WILL ALSO ALLOW A CHANCE OF THUNDERSTORMS CWA-WIDE
MONDAY AFTERNOON. COOL, SHOWERY WEATHER SHOULD CONTINUE THROUGH
THURSDAY NIGHT, BUT NEXT WEEKEND LOOKS WARMER AND SUNNIER AS
MODELS SHOW A PACIFIC UPPER RIDGE BUILDING INLAND. CURRENT
FORECAST IS ON TRACK.
AVIATION
MVFR/IFR CONDITIONS FROM CLOUDS/SHOWERS WILL DECREASE
THROUGH THE EVENING. PATCHY VALLEY FOG DEVELOPING OVERNIGHT.
MOUNTAINS OBSCURED BUT IMPROVING. AFTER PATCHY VALLEY FOG CLEARS
SUNDAY MORNING, VFR CONDITIONS ARE EXPECTED WITH INCREASING HIGH
CLOUDS IN THE AFTERNOON. SHOWERS AND LOW CEILINGS WILL ARRIVE
SW TO NE ACROSS THE AREA SUNDAY NIGHT. SNOW LEVELS 5-6KFT MSL
SUNDAY NIGHT. SURFACE WINDS: VARIABLE 10 KT OR LESS, THEN S-SE
5-15 KT WITH GUSTS TO 25 KT BY SUN/18Z. WINDS ALOFT AT 10KFT:
W-NW 10-20 KT, BECOMING S-SW 15-30 KT BY SUN/18Z.
KBOI...LOW CLOUDS GENERALLY DECREASING THIS EVENING. HOWEVER,
AROUND A 30% CHANCE OF IFR LOW STRATUS OR FOG DEVELOPING LATE
TONIGHT. SURFACE WINDS: VARIABLE LESS THAN 10 KT, THEN SE 5-15
KT ON SUNDAY.
HYDROLOGY
COOL SHOWERY CONDITIONS WILL CONTINUE THROUGH
MOST OF NEXT WEEK. SNOW LEVELS WILL REMAIN LOW, AND HEAVY
PRECIPITATION IS NOT EXPECTED AT THIS TIME. HOWEVER, MINOR
FLOODING IS FORECAST TO CONTINUE ON THE SILVIES RIVER NEAR
BURNS AND MALHEUR RIVER NEAR VALE THROUGH THE COMING WEEK.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT...A MID-LEVEL SHORT-
WAVE WAS CONTINUING TO SUPPORT SHOWERS AS IT SLOWLY ROTATES TO
THE EAST. MOST OF THE SHOWERS HAVE BEEN CENTERED AROUND ONTARIO,
WHICH PICKED UP MORE THAN A HALF INCH OF RAINFALL SO FAR TODAY.
THE MODELS DEPICT A GRADUAL DECREASE IN ACTIVITY THIS EVENING DUE
TO A COMBINATION OF THE LOSS OF DAYTIME HEATING AND ITS MOVEMENT
TO THE EAST OF THE AREA. SNOW LEVELS REMAIN NEAR 4500-5000 FEET
FOR ADDITIONAL LIGHT SNOWFALL ACCUMULATIONS IN THE MOUNTAINS.
THERE IS ABOUT A 12 HOUR DRY PERIOD LATE TONIGHT THROUGH SUNDAY
BETWEEN THE SYSTEM EXITING TO OUR EAST AND A WARM FRONT
APPROACHING FROM THE WEST. ANOTHER ROUND OF SHOWERS IS
ANTICIPATED ALONG THE WARM FRONT AS IT MOVES THROUGH THE AREA
SUNDAY AFTERNOON AND EVENING. SNOW LEVELS RISE TO AROUND 6000
FEET WITH THE FRONT, LIMITING ANY SNOWFALL TO THE HIGHER
MOUNTAINS. TEMPERATURES WILL BE MUCH WARMER THAN TODAY WITH
HIGHS CLOSE TO NORMAL. GUSTY SOUTHEAST TO SOUTHWEST WINDS
DEVELOP BY THE AFTERNOON, ESPECIALLY NEAR THE NEVADA BORDER
WHERE GUSTS TO 40 MPH ARE EXPECTED.
AN INCREASINGLY MOIST AND UNSTABLE SOUTHWEST FLOW ALOFT BRINGS
ANOTHER ROUND OF SHOWERS ON MONDAY AS A SHORT WAVE TROUGH MOVES
ACROSS THE REGION. THE SHOWER PROBABILITIES ARE GENERALLY ABOVE
70 PERCENT IN THE AFTERNOON ACROSS ALL OF SE OREGON AND SW
IDAHO. IN ADDITION TO THE SHOWERS, THE INSTABILITY IS HIGH
ENOUGH TO JUSTIFY A SLIGHT CHANCE (LESS THAN 25 PERCENT) OF
THUNDERSTORMS. SNOW LEVELS GENERALLY RANGE FROM 4500 TO 5500
FEET, WITH ADDITIONAL LIGHT SNOW ACCUMULATIONS EXPECTED IN THE
MOUNTAINS. BREEZY SOUTHWEST WINDS CONTINUE, MAINLY ALONG THE
NEVADA BORDER. TEMPERATURES WILL BE A FEW DEGREES COOLER. THE
SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH MONDAY NIGHT AS
THE TROUGH EXITS TO OUR EAST.
LONG TERM...TUESDAY THROUGH SATURDAY...GOOD MODEL CONSENSUS
THAT AN ACTIVE WEATHER PATTERN WILL CONTINUE THROUGHOUT NEXT
WEEK. ENSEMBLE CLUSTER ANALYSIS INDICATES NEARLY 100% OF MODEL
MEMBERS INDICATE A BROAD TROUGH OF LOW PRESSURE OVER MUCH OF
THE WESTERN US. THIS PATTERN WOULD ENTRENCH UNSETTLED, SHOWERY,
AND COOLER THAN AVERAGE CONDITIONS IN PLACE FOR OUR AREA. MORE
DETAILED DETERMINISTIC RUNS INDICATE SEVERAL WAVES OF LOW
PRESSURE MOVING THROUGH THE TROUGH ENHANCING PRECIPITATION,
FIRST TUESDAY INTO WEDNESDAY, AND THEN AGAIN THURSDAY INTO
FRIDAY. UNCERTAINTY BEGINS TO CREEP INTO THE DETAILS WITH THE
SECOND SYSTEM, WITH A SPLIT IN FAVORED SOLUTIONS. IN EITHER
CASE, UNSETTLED CONDITIONS SHOULD BE ANTICIPATED. BY THE WEEKEND
IT APPEARS THAT UPPER LEVEL RIDGING WILL BEGIN TO NUDGE INTO
THE REGION WITH MORE SEASONABLE CONDITIONS AND DRYING MOVING IN.
SNOW LEVELS ARE EXPECTED TO HOVER BETWEEN 3000 AND 4500 FEET
DURING THE WEEK, MEANING THE MOUNTAINS WILL LIKELY SEE AN
ADDITION TO THEIR SNOWPACK. CURRENT PROJECTIONS GIVE A 20-30%
CHANCE OF TWO INCHES OR MORE WITH EACH STORM IN MOUNTAIN VALLEYS
ABOVE 4500 FEET, INCLUDING MCCALL...AND A 30-40% CHANCE OF
EXCEEDING 3 INCHES IN THE HIGHER PEAKS.
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...LC
AVIATION.....ST
HYDROLOGY....BW
SHORT TERM...BW
LONG TERM....MC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page