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AGUS76 KRSA 231445

HMDRSA



Hydrometeorological Discussion

National Weather Service / California Nevada RFC / Sacramento CA

745 AM PDT Sat Mar 23 2024



...COOLER AIRMASS AND SHOWERS CONTINUE THIS WEEKEND...

...DRYING MONDAY INTO TUESDAY WITH NEXT SYSTEM ARRIVING MIDWEEK...



.METEOROLOGICAL CONDITIONS (SAT AM - FRI AM)...



As the upr ridge has been displaced downstream and an upr trof digs 

along the west coast...an associated cold front is sweeping across 

the area and is currently generally aligned from north-central NV 

back south-southwest across the southern Sierra...Tehachapis...and 

the LA Basin. Back behind the frontal boundary...scattered showers 

are developing in the cooler airmass and shifting onshore mainly 

along the northern and central CA coast and moving westward toward 

the interior. Through today...look for the cold front to clear the 

region to the south and east as one disturbance rotates through the 

base of the upr trof near the CA/MX border...while the primary 

circulation nears the OR coast. Best precip will be in the vicinity 

of these disturbances...while westerly onshore flow generates 

upslope conditions along the entire length of the Sierra and 

portions of the northern/central CA coastal mountains. Then into 

Sunday...as the base of the upr trof swings inland toward the Desert 

Southwest...the upr low located along the OR coast will drop toward 

the south-southeast along the CA coast before reaching northern Baja 

by early Monday. With lesser moisture available and flow turning a 

bit more northwesterly as an overall upr trof encompasses the 

western US...look for precip to drop off with the best totals across 

central CA and coastal southern CA from the southwest San Bernardino 

mountains down to the CA/MX border...in nearest vicinity of the 

disturbance moving through the overall flow. 



Into early next week on Monday...the upr trof will shift downstream 

of the area as anti-cyclonic flow sets up over the eastern 

Pacific...and then moves across the west coast later Tuesday into 

Wednesday. This will keep much of the area dry under northwesterly 

flow aloft. There may be a few showers across the northern tier on 

Monday and Tuesday in the northwesterly flow...but amounts and 

coverage will be light and scattered.



The next system will begin to enter the picture on Wednesday into 

Thursday...with overall timing slightly slower than previous 

thinking. The latest NBM has trended this way...along with the 

operational deterministic models from the 23/00Z run...and the 

forecast issuance followed this scenario. Best precip on Wednesday 

into Thursday looks to fall along coastal areas from the Russian 

River basin northward...and the inland over the crest of the 

southern OR Cascades down across the Shasta Lake drainage and much 

of the Sierra with 1.00- to 3.00-inches again...similar to the 

current system. 



Freezing levels will are dropping today as the cooler airmass 

filters in across the region and bottoming out early Sunday from 

3500- to 6000-feet from northwest to southeast...with levels in the 

vicinity of I-80 from 4000- to 4500-feet. Then look for a gradual 

increase as the upr ridge slides across the area early next week on 

Tuesday...peaking during the afternoon hours from 6000-feet 

northwest to 9500-feet southwest. Then with the next troffing moving 

across the area for midweek toward the end of the week...these will 

fall once again...down to about 3000-feet northwest to 8500-feet 

southeast...between 3500- and 4500-feet along I-80. 





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







Kozlowski



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