515  
NGUS86 KRSA 131436  
HCMRSA  
 
HYDROMETEOROLOGICAL COORDINATION MESSAGE  
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA  
735 AM PDT SAT APR 13 2024  
   
..COOLER AND UNSETTLED CONDITIONS THIS WEEKEND
 
   
..DRYING THROUGH NEXT WEEK WITH TEMPERATURES REBOUNDING
 
 
   
METEOROLOGICAL CONDITIONS (SAT AM - FRI AM)
 
 
THIS WEEKEND WILL SEE THE MOST IMPACTFUL CONDITIONS IN TERMS OF  
PRECIP AS AN AREA OF LOW PRESSURE IS SPINNING WEST OF THE SF BAY  
AREA GENERALLY ALONG 125.5W THIS MORNING. THE LINE OF PRECIP  
ASSOCIATED WITH THE FRONTAL BOUNDARY IS CURRENTLY ARCHING FROM NEAR  
CAPE MENDOCINO BACK ACROSS THE NORTHERN CA COASTAL MOUNTAINS AND  
THEN THROUGH THE SF BAY AREA AND DOWN TO THE CENTRAL CA COAST. SINCE  
13/12Z...PRECIP GAUGES SHOW THE BEST TOTALS RANGING FROM 0.10- TO  
0.25-INCH WITH SOME LOCALIZED HIGHER AMOUNTS. FAVORABLE UPSLOPE FLOW  
IS OCCURRING ALONG THE WEST SIDE OF THE SACRAMENTO VALLEY AND  
ADJACENT COASTAL MOUNTAINS AS SOUTHEAST LOW- TO MID-LEVEL FLOW  
EXISTS IN THE NORTHEAST QUADRANT TO THE AREA OF LOW PRESSURE.  
 
MODELS ARE IN REASONABLE AGREEMENT WITH THE PROGRESSION OF THE  
SYSTEM TODAY WITH PRIMARY CIRCULATION SLOWLY DROPPING TOWARD THE  
SOUTHEAST BEFORE EVENTUALLY MOVING INLAND SOMEWHERE ALONG THE  
MONTEREY COUNTY COAST SUNDAY MORNING. THE LINE OF PRECIP WILL SHIFT  
INLAND AND SOUTHWARD THIS AFTERNOON WITH THE BEST AMOUNTS FOCUSED  
FROM THE AMERICAN RIVER BASIN DOWN TO THE UPPER PORTIONS OF THE SAN  
JOAQUIN RIVER BASIN AND ACROSS AREAS NEAR POINT CONCEPTION...WHICH  
INCLUDE THE SANTA YNEZ MOUNTAINS WHERE A BRIEF PERIOD OF SOUTHERLY  
FLOW EXISTS AHEAD OF THE FRONTAL BOUNDARY. ALSO...A MID-LEVEL VORT  
MAX WILL ROTATE THROUGH THE CYCLONIC FLOW...WHICH WILL ENHANCE  
PRECIP ACROSS THIS AREA. BY THE EVENING AND OVERNIGHT...PRECIP WILL  
FOCUS OVER AREAS IN THE VICINITY OF THE PRIMARY CIRCULATION NEAR THE  
SF BAY AREA AND CENTRAL CA COAST...THE SOUTHERN SIERRA ALONG WITH  
THE SAN GABRIEL AND SAN BERNARDINO MOUNTAINS WHERE THE FRONTAL  
BOUNDARY WILL BE TRAVERSING...AND THEN NEAR THE CA/OR BORDER IN AN  
AREA OF CONVERGENT FLOW.  
 
SUNDAY WILL SEE THE AREA OF LOW PRESSURE TRACK INLAND TOWARD  
SOUTHERN NV WITH PRECIP TAPERING OFF AS THE NEW WORK WEEK STARTS. A  
COUPLE DISTURBANCES MOVING THROUGH THE CYCLONIC FLOW WILL BRING THE  
BEST PRECIP TO AREAS NEAR POINT CONCEPTION AND FAR SOUTHERN SIERRA  
WITH THE OTHER BEING IN THE VICINITY OF THE CA/OR BORDER.  
 
OVERALL TOTALS FROM THIS MORNING THROUGH MONDAY MORNING 12Z...THE  
NEXT 48 HOURS...WILL GENERALLY BE FROM 0.75- TO 1.50-INCH WITH A FEW  
LOCALIZED AREAS CLOSER TO 2.00-INCHES ACROSS THE HIGHER TERRAIN FROM  
AREAS NEAR THE CA/OR BORDER DOWN TO THE TRANSVERSE RANGES OF  
SOUTHERN CA. CENTRAL VALLEY LOCATIONS MAY BE SLIGHTLY LESS...WITH  
APPROX 0.33- TO 0.75-INCH WITH SOME AREAS ON THE EAST SIDE OF THE  
SAN JOAQUIN VALLEY APPROACHING 1.00-INCH.  
 
FREEZING LEVELS ARE STARTING TODAY WITH AN TIGHT EAST-TO-WEST  
GRADIENT...FROM 9000- TO 11500-FEET ACROSS MUCH OF NV AND SOUTHERN  
CA...WHILE THE COOLER AIRMASS NEAR THE AREA OF LOW PRESSURE IS DOWN  
TO 3500- TO 5500-FEET ACROSS COASTAL NORTHERN CA DOWN THROUGH THE SF  
BAY AREA AND MONTEREY BAY AREA. AS THE AREA OF LOW PRESSURE MOVES  
INLAND LATER TODAY INTO EARLY SUNDAY...THESE WILL BOTTOM OUT WITH  
3500- TO 5500-FEET ACROSS MUCH OF NORTHERN AND CENTRAL CA AND THEN  
EVENTUALLY 5500- TO 7000-FEET FOR NV DOWN TOWARD SOUTHERN CA.  
 
AFTER THIS SYSTEM MOVES DOWNSTREAM OF THE AREA ON MONDAY...DRY  
CONDITIONS ARE EXPECTED TO SET UP SHOP FOR THE REST OF THE WEEK AS  
MODEST HIGH PRESSURE BUILDS OVER THE AREA...AND TEMPERATURES WARM  
BACK TO OR JUST ABOVE NORMAL.  
 
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  
 
KOZLOWSKI  
 

 
 
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