886  
FXUS65 KBOI 040819  
AFDBOI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOISE ID  
219 AM MDT FRI JUL 4 2025  
   
SHORT TERM...TODAY THROUGH SUNDAY NIGHT  
A STRONG UPPER LEVEL  
POSITIVELY-TILTED SHORTWAVE WILL MOVE INTO THE REGION TODAY AND  
HELP KEEP THUNDERSTORMS GOING. MOST AREAS CAN EXPECT MULTIPLE  
ROUNDS OF SHOWERS AND STORMS. AS OF 2 AM MDT, SHOWERS AND STORMS  
WERE MOST NUMEROUS SOUTH OF BOISE, BUT THERE WERE ADDITIONAL  
SHOWERS AND STORMS IN THE MOUNTAINS. MESOSCALE MODELS ARE  
REASONABLY CONSISTENT SHOWING THIS ACTIVITY INCREASING THROUGH  
SUNRISE AS STORMS CONTINUE TO MOVE NORTH. LATEST QPF GUIDANCE  
CONTINUES TO SHOW THE POSSIBILITY OF HIGH RAINFALL RATES IN THE  
MOUNTAINS THIS MORNING, AND THE FLASH FLOOD WATCH WILL BE  
MAINTAINED AS ISSUED. WE CONSIDERED MOVING THE START TIME UP A  
COUPLE HOURS, BUT IT APPEARS THAT THE STRONGEST RAIN RATES WILL  
OCCUR AROUND AND AFTER 12Z, SO A CHANGE IS NOT NEEDED. RED FLAG  
WARNINGS CONTINUE ACROSS EASTERN OREGON TODAY, AND SEEM  
APPROPRIATE BASED ON SEVERAL BANDS OF THUNDERSTORMS THAT SHOULD  
MOVE ACROSS THE REGION THIS MORNING THROUGH EARLY EVENING.  
INSTABILITY WILL BE EXTREME FOR THIS AREA, WITH CAPE VALUES  
FORECAST OVER 1000 J/KG OVER A SIZABLE AREA AROUND MIDDAY. SHEAR  
INCREASES TODAY COMPARED TO YESTERDAY AS THE SHORTWAVE TROUGH  
MOVES THROUGH, AND SUPERCELLS MAY FORM, ESPECIALLY THIS  
AFTERNOON. NOT COINCIDENTALLY, SPC HAS PUT NEARLY OUR ENTIRE CWA  
INTO A MARGINAL RISK FOR SEVERE THUNDERSTORMS. SOME STORMS ARE  
EXPECTED TO PRODUCE WIND GUSTS 40-60 MPH, HAIL UP TO 1 INCH IN  
DIAMETER, AND BRIEF TORRENTIAL RAIN. PW VALUES NEAR 0.90 INCH  
PUT US NEAR THE 90TH PERCENTILE THIS MORNING, BEFORE DRIER AIR  
MOVES IN THIS AFTERNOON INTO THE EVENING. SHOWERS AND STORMS  
SHOULD CONTINUE INTO THE EVENING BEFORE DIMINISHING AROUND  
MIDNIGHT TONIGHT. THERE IS STILL A SLIGHT CHANCE OF SHOWERS AND  
THUNDERSTORMS IN EASTERN VALLEY COUNTY SATURDAY, BUT SUNDAY  
WILL BE DRY WITH A WARMING TREND AS TEMPERATURES RETURN TO NEAR  
NORMAL. TEMPERATURES TODAY AND SATURDAY ARE EXPECTED TO BE  
RELATIVELY COOL FOR THIS TIME OF YEAR, WITH READINGS IN THE  
LOWER TO MID 80S AT LOWER ELEVATIONS. WINDS SHOULD MAINLY OUT  
OF THE NW AT 5-15 MPH TODAY AND SATURDAY EXCEPT NEAR SHOWERS  
AND THUNDERSTORMS.  
   
LONG TERM...MONDAY THROUGH FRIDAY  
STRONG RIDGING WILL BUILD INTO  
THE AREA FROM THE FOUR CORNERS REGION THROUGHOUT THE LONG-TERM,  
SUSTAINING HOT AND DRY CONDITIONS MONDAY TO FRIDAY. A TROUGH OFF THE  
COAST OF CALIFORNIA IS EXPECTED TO KEEP OUR AREA IN SOUTHERLY  
FLOW ALOFT. AS THE RIDGE BUILDS, TEMPERATURES TAKE ON A  
SIGNIFICANT WARMING TREND REACHING ROUGHLY 10 DEGREES ABOVE  
NORMAL, WITH VALLEY DAYTIME TEMPERATURES REACHING OR EXCEEDING  
THE UPPER 90S THROUGHOUT THE WEEK. HEAT HEADLINES MAY BE NEEDED  
IN THE WEEK TO COME AS A RESULT OF THE PROLONGED HOT  
TEMPERATURES. INFLUXES OF UPPER-LEVEL MONSOONAL MOISTURE STEERED  
BY THIS PATTERN INTERACTION CANNOT BE RULED OUT FOR THE  
EXTENDED PERIOD. A SLIGHT RIDGE BREAKDOWN IS POSSIBLE THURSDAY  
AS THE TROUGH OFF THE CALIFORNIA COAST IS EXPECTED TO BRIEFLY  
DIG ACROSS THE NORTHWEST AS A SHORTWAVE TOWARDS THE END OF THE  
WEEK.  
 
 
   
AVIATION  
NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH THIS  
MORNING, BECOMING SCATTERED THIS AFTERNOON/EVENING. THREATS:  
ERRATIC OUTFLOW GUSTS 30-45 KT, SMALL HAIL, LIGHTNING, MODERATE TO  
HEAVY RAINFALL. LOCALIZED MVFR/IFR CONDITIONS AND MOUNTAIN  
OBSCURATION IN STORMS. SURFACE WINDS OUTSIDE OF STORMS: VARIABLE 5-  
15 KT. WINDS ALOFT AT 10KFT MSL: GENERALLY S-SW 10-20 KT.  
 
KBOI...MOSTLY VFR. PERIODS OF SHOWERS/THUNDERSTORMS THROUGH  
AROUND 14Z. THREATS: ERRATIC OUTFLOW GUSTS TO 30-45 KT, SMALL  
HAIL, LIGHTNING, MODERATE TO HEAVY RAINFALL. MVFR CONDITIONS  
POSSIBLE WITH STORMS, ALONG WITH FOOTHILL OBSCURATION.  
SHOWERS/THUNDERSTORMS EXIT AFTER FRIDAY 14Z, THEN ANOTHER CHANCE  
OF THUNDERSTORMS THIS AFTERNOON AROUND 20Z AND AFTER. SURFACE  
WINDS OUTSIDE OF STORMS: NW 5-15 KT, BECOMING SW-NW 5-15 KT  
OVERNIGHT.  
 
WEEKEND OUTLOOK...GENERALLY VFR. A 15-25% CHANCE OF SHOWERS AND  
THUNDERSTORMS SATURDAY MORNING IN W-CENTRAL IDAHO MOUNTAINS, THEN  
CLEARING THROUGH SUNDAY. SURFACE WINDS VARIABLE OR NW 5-15 KT.  
 
 
   
BOI WATCHES/WARNINGS/ADVISORIES  
 
ID...FLASH FLOOD WATCH FROM 6 AM MDT THIS MORNING THROUGH THIS  
AFTERNOON IDZ011-013.  
OR...RED FLAG WARNING UNTIL 11 PM MDT /10 PM PDT/ THIS EVENING  
ORZ670-672>674.  
 
 
 
 
 
WWW.WEATHER.GOV/BOISE  
 
INTERACT WITH US VIA SOCIAL MEDIA:  
WWW.FACEBOOK.COM/NWSBOISE  
WWW.X.COM/NWSBOISE  
 
SHORT TERM...SP  
LONG TERM....JY  
AVIATION.....JY  
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