701  
FXUS65 KBOI 081528  
AFDBOI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOISE ID  
928 AM MDT THU MAY 8 2025  
   
DISCUSSION  
WEAK COLD FRONT MOVED THROUGH OUR CWA OVERNIGHT,  
AND TODAY WILL BE SUNNY WITH BREEZY NORTHWEST WINDS THIS  
AFTERNOON. THE WARMING TREND IS HALTED FOR TODAY ONLY, WITH  
FORECAST HIGH TEMPS TODAY SIMILAR TO HIGHS YESTERDAY. BUT  
FRIDAY WILL BE 8 TO 10 DEGREES WARMER, AND SATURDAY EVEN  
ANOTHER 1-3 DEGREES WARMER ON THE IDAHO SIDE, WHILE OREGON  
BEGINS TO COOL. A PACIFIC UPPER TROUGH/LOW WILL APPROACH THE  
NORTHWEST COAST SATURDAY, WITH BIG WEATHER CHANGES IN OUR CWA  
SUNDAY AND MONDAY AS THE UPPER LOW MOVES INLAND. THESE CHANGES  
INCLUDE SHOWERS, THUNDERSTORMS, GUSTY WINDS, AND 20 TO 25  
DEGREES COOLING, WITH TUESDAY THE COOLEST DAY. CURRENT FORECAST  
COVERS ALL THIS. NO UPDATES.  
 
 
   
AVIATION  
VFR WITH HIGH CLOUDS FILLING IN THIS EVENING.  
SURFACE WINDS: W-NW 5-15 KT BECOMING VARIABLE LESS THAN 10 KT  
BY FRI/03Z. WINDS ALOFT AT 10KFT MSL: SW 15-25 KT.  
 
KBOI...VFR. NW WINDS 8-10 KT, SHIFTING TO E-SE 4-8 KT OVERNIGHT.  
 
WEEKEND OUTLOOK...SATURDAY WILL BE WARM AND DRY WITH INCREASING  
CLOUDS. SHOWERS AND THUNDERSTORMS POSSIBLE (15-30%) OVER THE BOISE  
MOUNTAINS AND ID/NV BORDER LATE AFTERNOON INTO EVENING. ON SUNDAY  
AFTERNOON, A COLD FRONT WILL MOVE FROM SE OR INTO SW ID, BRINGING  
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WITH GUSTY WESTERLY  
WINDS, LOWERING CEILINGS, AND MOUNTAIN OBSCURATION.  
 
 
   
PREV DISCUSSION  
 
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...WARM AND DRY  
CONDITIONS WILL CONTINUE ACROSS THE REGION TODAY, WITH  
TEMPERATURES RUNNING ABOUT 10 DEGREES ABOVE NORMAL. A WEAK  
FRONTAL PASSAGE EARLY THIS MORNING TEMPORARILY FLATTENED THE  
RIDGE, KEEPING TODAY’S HIGHS NEAR YESTERDAY’S LEVELS—GENERALLY  
IN THE UPPER 70S ACROSS THE LOWER VALLEYS.  
 
ON FRIDAY, THE RIDGE WILL EXPAND NORTHWARD OVER THE NORTHERN  
ROCKIES, ALLOWING TEMPERATURES TO RISE ANOTHER 8 TO 10 DEGREES,  
WITH HIGHS REACHING THE UPPER 80S IN THE VALLEYS. BY SATURDAY,  
A DEEPENING UPPER-LEVEL LOW WILL APPROACH THE PACIFIC NORTHWEST  
COAST, INCREASING SOUTHWESTERLY FLOW AND DRAWING IN ADDITIONAL  
MOISTURE ALOFT. THIS WILL TIGHTEN THE PRESSURE GRADIENT,  
RESULTING IN BREEZY SOUTHERLY WINDS ACROSS THE AREA. THE  
COMBINATION OF WARM AIR AND DOWNSLOPE FLOW WILL HELP PUSH VALLEY  
TEMPERATURES TO NEAR RECORD LEVELS, WITH HIGHS IN THE LOW 90S.  
 
THERE ALSO APPEARS TO BE SUFFICIENT HIGH-LEVEL MOISTURE  
(PRECIPITABLE WATER VALUES IN THE 60TH PERCENTILE) AND  
INSTABILITY (CAPE) TO SUPPORT THUNDERSTORM DEVELOPMENT SATURDAY  
AFTERNOON. INVERTED-V SOUNDINGS SUGGEST THAT STRONGER STORMS MAY  
PRODUCE GUSTY OUTFLOW WINDS. STORMS ARE MOST LIKELY TO INITIATE  
OVER THE HIGHER TERRAIN OF SOUTHWEST IDAHO, WHERE OROGRAPHIC  
LIFT WILL AID CONVECTION.  
 
LONG TERM...SUNDAY THROUGH THURSDAY...INCOMING UPPER-LEVEL  
TROUGH PENDING, A COOL AND CLOUDY LONG TERM IS ON THE WAY. A COLD  
FRONT WILL MOVE THROUGH THE REGION SUNDAY AFTERNOON INTO MONDAY,  
BRINGING GUSTY WINDS, COOLER TEMPS, AND SHOWERS AND THUNDERSTORMS.  
SHOWER AND THUNDERSTORM CHANCES SUNDAY WILL BE GREATEST IN BAKER,  
ADAMS, AND VALLEY COUNTIES WITH CHANCE RANGING FROM 30-50%. THE REST  
OF THE REGION CURRENTLY IS SITTING 15-30% CHANCE. GUSTY WINDS WILL  
BE GREATEST SUNDAY AFTERNOON INTO EVENING, PARTICULARLY IN SOUTHERN  
HARNEY, MALHEUR, AND OWYHEE COUNTIES WHERE GUSTS MAY REACH 40 KTS.  
SNOW LEVELS WILL DECREASE FROM 8,000-9,500 FEET SUNDAY AFTERNOON  
TO 5,500-7,000 FEET THROUGH THE EXTENDED PERIOD, WITH HIGHEST  
LEVELS OCCURRING IN THE WESTERN MAGIC VALLEY. SHOWER CHANCES  
REMAIN INTO MONDAY AT 50-70% IN THE WEST-CENTRAL MOUNTAINS,  
DECREASING TO 30-45% ELSEWHERE. THE COLD FRONT WILL BRING HIGH  
TEMPS MONDAY AND TUESDAY 15-20 DEGREES COOLER THAN THE WEEKEND.  
SHOWERS REMAIN POSSIBLE TUESDAY AND WEDNESDAY, DIMINISHING IN  
SE OR WEDNESDAY, AND THUNDERSTORMS REMAIN POSSIBLE IN THE  
WESTERN MAGIC VALLEY BOTH DAYS AS WELL. THE UPPER-LEVEL TROUGH  
WILL MEANDER OVERHEAD UNTIL LATE TUESDAY INTO WEDNESDAY. FROM  
WEDNESDAY INTO THURSDAY, THE GFS PUTS US UNDER NW FLOW ALOFT,  
WHILE THE ECMWF AND CANADIAN BUILD A HIGH AMPLITUDE SHORTWAVE  
RIDGE. ALTHOUGH THE SOLUTIONS DIFFER, THE NET RESPONSE WILL BE A  
DRIER PATTERN, PROVIDING SOME RELIEF FROM PRECIPITATION FOR THE  
TIME.  
 
 
   
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.....SA  
SHORT TERM...JDS  
LONG TERM....CH  
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