073  
NGUS86 KRSA 011418  
HCMRSA  
 
HYDROMETEOROLOGICAL COORDINATION MESSAGE  
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA  
720 AM PDT THU JUN 1 2023  
   
..SHOWERS/T-STORMS FOR PARTS OF THE AREA THE REST OF THE WEEK
 
 
...COOLER TEMPERATURES WILL GIVE WAY TO NEAR/ABOVE NORMAL  
TEMPERATURES THIS WEEKEND BEFORE THE NEXT SYSTEM EARLY TO MID NEXT  
WEEK BRINGS TEMPS BACK DOWN AND RETURNS SHOWERS/T-STORMS...  
   
METEOROLOGICAL CONDITIONS (THU AM - WED AM)
 
 
THE UPPER LOW THAT MOVED THROUGH SOUTHERN CA YESTERDAY IS NOW FIRMLY  
OVER AZ EARLY THIS MORNING AS A SHORTWAVE SITS JUST OFFSHORE OF THE  
CA/OR BORDER. A SECOND BROADER TROUGH IS ALSO SOUTHWEST OF SOCAL  
APPROACHING BAJA. BLENDED TPW SATELLITE IMAGERY SHOWS 0.50-0.75" PW  
OF MOISTURE ACROSS MUCH OF THE REGION ONCE AGAIN. THE COMBINATION OF  
THESE FACTORS MEAN CONTINUED AFTERNOON/EVENING SHOWER AND  
THUNDERSTORM ACTIVITY, MAINLY FOR THE SIERRA AND OVER NV. THE  
APPROACHING SHORTWAVE WILL MOVE THROUGH NORTHERN CA/SOUTHERN OR THE  
REST OF TODAY ENTERING NV BY EARLY FRIDAY MORNING. BEHIND BOTH  
TROUGHS, AN UPPER RIDGE WILL BUILD IN OVER CA ON FRIDAY. ISOLATED  
CONVECTIVE SHOWERS AND THUNDERSTORMS STILL POSSIBLE TOMORROW  
AFTERNOON/EVENING OVER PARTS OF THE SIERRA AND NV, BUT NOT AS MUCH  
ACTIVITY IS FORECAST AS THE PAST FEW DAYS. TEMPERATURES EXPECTED TO  
REMAIN NEAR TO BELOW NORMAL AGAIN TODAY BEFORE THE RIDGE BEGINS TO  
WARM CONDITIONS SOME INTO THE WEEKEND. THE RIDGE WILL CONTINUE TO  
BUILD OVER THE WEEKEND RESULTING IN NEAR TO AS MUCH AS 10 DEG F  
ABOVE NORMAL TEMPERATURES ACROSS NORTHERN CA AND DOWN THE VALLEYS.  
DAYTIME HEATING AND THE CONTINUED PRESENCE OF MOISTURE MAY ALLOW FOR  
A FEW SHOWERS OR EVEN A THUNDERSTORM OR TWO ACROSS THE SIERRA  
SATURDAY AFTERNOON/EVENING AS WELL AS OVER EASTERN NV WHERE  
INFLUENCE FROM THE LATE WEEK SHORTWAVE PERSISTS.  
 
THE NEXT SYSTEM WILL APPROACH FROM WEST OF POINT CONCEPTION ON  
SUNDAY AS AN UPPER LOW. MODELS REMAIN IN DISAGREEMENT OVER THIS LOW.  
THE GFS HAS IT FORMING A BIT EARLIER WHILE OFFSHORE AND BRINGING  
LIGHT PRECIP TO THE CENTRAL/SOCAL COASTS MONDAY MORNING. THE ECMWF  
IS DRIER AND HOLDS OFF ON CLOSING THE LOW A LITTLE LONGER. BOTH  
MODELS DO SHOW THE UPPER LOW MAKING LANDFALL OVER SOCAL ON MONDAY  
AND SPREADING ACROSS MOST OF CA/NV BY THE EVENING. THIS WILL RESULT  
IN ADDITIONAL SHOWER ACTIVITY OVER THE REGION WITH POTENTIAL FOR  
MORE THUNDERSTORMS AS WELL. THE LOW IS THEN EXPECTED TO REMAIN OVER  
THE AREA THROUGH TUESDAY CONTINUING TO GENERATE SHOWERS AND POSSIBLY  
THUNDERSTORMS WITH THE HIGHEST AMOUNTS ACROSS THE SIERRA. THIS NEXT  
SYSTEM WILL ALSO ACT TO REDUCE TEMPERATURES EARLY TO MID NEXT WEEK  
FROM SW TO NE. AFTERNOON HIGHS SHOULD BE NEAR NORMAL FOR MOST PLACES  
BY TUESDAY TO AS MUCH AS 15 DEG F BELOW NORMAL FOR SOME AREAS SOUTH  
OF I-80.  
 
THE MAJORITY OF THE PRECIPITATION IN THE FORECAST IS EXPECTED FROM  
THIS SYSTEM WITH LESSER AMOUNTS DUE TO SCATTERED SHOWERS AND  
THUNDERSTORMS THE NEXT FEW DAYS. TOTAL QPF FOR THE NEXT 6 DAYS IS AS  
FOLLOWS: 0.50-1.50" ACROSS THE SIERRA, 0.25-1.25" OVER THE NV  
MOUNTAINS, 0.10-0.60" ACROSS NORTHERN CA, 0.10-0.25" LOWER  
ELEVATIONS OF NV, AND GENERALLY 0.10" OR LESS FOR THE REST OF CA.  
LOCALLY HIGHER AMOUNTS WHERE THUNDERSTORMS DEVELOP.  
 
QPF GRAPHICS ARE AVAILABLE AT WWW.CNRFC.NOAA.GOV/QPF.PHP  
 
*********************** CONTACT INFORMATION ************************  
 
CNRFC OFFICE HOURS PHONE: 1 (916) 979-3056 EXTENSION 338  
AFTER-HOURS CALLING SERVICE: 1 (800) 218-0858  
LEAVE NAME...OFFICE...AND PHONE NUMBER  
 
AS  
 

 
 
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