661  
FXUS66 KSTO 151955  
AFDSTO  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SACRAMENTO CA  
1255 PM PDT FRI AUG 15 2025  
   
DISCUSSION  
 
   
SYNOPSIS  
 
WARMER WEATHER TODAY, THEN NEAR TO BELOW NORMAL TEMPERATURES  
THROUGH THE WEEKEND AND INTO NEXT WEEK WITH MAINLY MINOR HEATRISK  
AND PERIODICALLY BREEZY ONSHORE FLOW. SLIGHT CHANCE OF  
THUNDERSTORMS MAINLY OVER SHASTA COUNTY VICINITY THIS WEEKEND,  
OTHERWISE DRY CONDITIONS PREVAIL.  
 
 
   
KEY MESSAGES  
 
*TODAY:  
- SLIGHTLY WARMER TODAY WITH DRY CONDITIONS  
- AFTERNOON HIGHS THE 90S TO NEAR 100 FOR MUCH OF THE VALLEY AND  
FOOTHILLS  
- WIDESPREAD MINOR HEATRISK WITH LOCALIZED MODERATE HEATRISK  
 
*WEEKEND:  
- COOL DOWN WITH NEAR TO BELOW AVERAGE TEMPERATURES OVER THE  
WEEKEND WITH MINOR HEATRISK AND RISING RELATIVE HUMIDITY  
- PERIODICALLY BREEZY ONSHORE FLOW IS FORECAST AT TIMES,  
STRONGEST IN THE DELTA VICINITY AND OVER THE SIERRA CREST  
- 15-35% CHANCE OF MOSTLY WET THUNDERSTORMS IN SHASTA COUNTY  
(INCLUDES NORTHERN SACRAMENTO VALLEY), NORTHERN COASTAL RANGE,  
AND SOUTHERN CASCADES, DRY WEATHER ELSEWHERE  
- POTENTIAL FOR NOCTURNAL CONVECTION SATURDAY NIGHT INTO SUNDAY  
MORNING AS WELL MAINLY IN SHASTA COUNTY  
 
*NEXT WEEK:  
- BELOW NORMAL TEMPERATURES ON MONDAY WILL GRADUALLY WARM BACK UP  
TO NEAR NORMAL THROUGH NEXT WEEK AS HIGH PRESSURE IS FAVORED  
TO BUILD BACK IN OVER THE WESTERN US, CENTERED OVER THE FOUR  
CORNERS REGION  
- WIDESPREAD MODERATE HEATRISK RETURNS TO THE FORECAST LATE NEXT  
WEEK AS A RESULT OF THE WARMING TREND  
- DRYING TREND WILL BRING LOWER RELATIVE HUMIDITY TO THE AREA MID  
TO LATE NEXT WEEK, AROUND 15-20% IN THE AFTERNOONS  
   
CHANGES FROM PREVIOUS FORECAST  
 
- ADDED MENTION OF THE POTENTIAL FOR NOCTURNAL CONVECTION  
SATURDAY NIGHT INTO SUNDAY MORNING OVER SHASTA COUNTY VICINITY  
 
 
   
AVIATION  
 
VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS ACROSS  
INTERIOR NORCAL. SUSTAINED SURFACE WINDS GENERALLY AT OR BELOW 12  
KTS EXCEPT IN THE DELTA WITH WEST-SOUTHWEST SURFACE WINDS 12-15  
KTS WITH GUSTS 20-25 KTS 23Z FRIDAY - 15Z SATURDAY. NORTHERLY  
SURFACE WIND GUSTS OF UP TO 15-20 KTS IN THE NORTHERN SACRAMENTO  
VALLEY THROUGH 03Z SATURDAY.  
 
 
   
STO WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab CA Page
Main Text Page