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AGUS76 KRSA 031941

HMDRSA



Hydrometeorological Discussion

National Weather Service / California Nevada RFC / Sacramento CA

1240 PM PDT Wed Apr 3 2024



...COOLER AND INCREASING PRECIP FOR LATTER HALF OF THE WEEK...

...DRYING INTO EARLY NEXT WEEK...



.METEOROLOGICAL CONDITIONS (SHORT TERM: WED PM - SAT AM)...



The cold front associated with the polar s/wv trof dropping down the 

west coast is now making its way across northern CA early this 

afternoon with a wind shift and cooler temperatures already 

occurring at several observation stations...including Crescent 

City...Arcata...and inland near Siskiyou/Montague. Still expecting a 

band of precip to develop from the eastern Shasta Lake drainage up 

toward the northeast CA Plateau and portions of the upper Klamath 

River basin. Also...upslope precip across the northern/central 

Sierra will also begin ramping up later today.



On Thursday...the core of the upr trof will being to move inland as 

it continues to dig toward the south as well. Widespread precip is 

expected from the Russian/Eel River basins southward through the SF 

Bay Area and Santa Cruz mountains to the Big Sur coast. Then inland 

amounts will tick up across much of the Sierra with the focus of the 

heaviest totals between the Stanislaus/Tuolumne River basin down 

through the Kings River basin. Models continue to show a band of 

precip developing ahead of the upr trof axis from north-central NV 

back to the west-central portion of the state. Finally...by Friday 

the system swings inland with the base of the upr trof crossing 

coastal southern CA with increasing amounts of precip...especially 

from southwest San Bernardino county down to the CA/MX border. 



Freezing levels will be anomalously low for this time of 

year...bottoming out on Friday morning as the core of the polar 

airmass moves overhead...down to about 1500- to 4500-feet from 

northwest to southeast. 





.METEOROLOGICAL CONDITIONS (LONG TERM: SAT AM - TUE AM)...



Guidance continues to suggest a s/wv will dig southeastward over 

California beginning overnight Saturday and continuing the unsettled 

and colder pattern into early next week. Model-to-model and run-to-

run differences in the timing, phase and location of the s/wv 

continue to result in uncertainties on the specifics surrounding 

precipitation across the region. While differences have persisted 

into the afternoon forecast, accumulations are generally low with 24-

hour QPF <0.10 inches across the forecast are on each day, though as 

much as 0.15 inches could fall over the Smith and Shasta basins on 

Saturday. Afternoon forecasts primarily followed guidance from the 

WPC while working in some solutions from the GFS and EC. Ridging is 

forecast to build over California on Tuesday morning as the s/wv 

begins to propagate inland, resulting in warmer and drier conditions.



Freezing levels will start the forecast period below 3,000 feet 

across the North and 5,000 feet across the South on Saturday before 

rising under a ridging pattern to above 5,000 feet along the Coast 

and 4,000 feet across Nevada by Tuesday morning.





QPF graphics are available at www.cnrfc.noaa.gov/qpf.php







Kozlowski/CH



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