####018003713####
AGUS76 KRSA 082049

HMDRSA



Hydrometeorological Discussion

National Weather Service / California Nevada RFC / Sacramento CA

1250 PM PST Fri Mar 8 2024



...DRY CONDITIONS ACROSS THE REGION TODAY...

...A SERIES OF SYSTEMS WILL BRING PRECIP TO THE NRN HALF OF THE 

REGION THIS WEEKEND THROUGH EARLY NEXT WEEK...



.METEOROLOGICAL CONDITIONS (SHORT TERM: FRI PM - MON AM)...



Dry conditions continue this afternoon as an upper ridge resides 

over the west coast. Forecast overall remains on track this 

afternoon for a pair of systems to move through this weekend 

bringing precip to the northern portion of the region. Little change 

with the first system as an upper trough arriving early Saturday 

morning before moving inland across the PacNW/nrn CA in the morning 

and lifting northeastward out of the area in the afternoon/evening. 

This will bring showers to nrn CA and srn OR for Saturday. QPF for 

the first system has not changed hardly at all since the morning 

forecast. 



The second system, a surface/upper low, is set to bring showers into 

the north coast by early Sunday morning. Precip will spread across 

the nrn CA coast and inland into the afternoon as the low opens into 

an upper trough stretched offshore from BC through nrn CA. The 

trough will then progress inland the rest of the short term. Models 

show a bit of a decrease in QPF compared to this morning, 

particularly for the Sunday morning time frame as the ECMWF has 

slowed down the system just a bit. These decreases have crept into 

the ensembles and the NBM as well resulting in a lowering of QPF for 

Sunday by about 0.10-0.50".



Highest precip amounts through 12z Monday forecast for the north 

coast at about 1.50-3.50" (locally higher for isolated spots). QPF 

for the rest of the area: 1-2" Shasta, 0.50-1.50" northern Sierra 

and rest of the nrn CA coast, 0.10-0.75" central Sierra/Bay Area, 

and a few hundredths to 0.50" or so down the valleys. Majority of 

the precipitation for these events expected north of I-80. 



Freezing levels lowering into Saturday morning down to 4-7 kft north 

of I-80 dropping further into the afternoon to 3.5-6.5 kft. Levels 

will fluctuate the rest of the weekend but remain generally around 

those heights until spreading further to the south into early Monday 

at 3-4.5 kft north of I-80 and 4.5-8.5 kft to Point Conception.





.METEOROLOGICAL CONDITIONS (LONG TERM: MON AM - THU AM)...



One exiting s/wv trof moving from northern NV toward UT...while the 

next in a series of disturbances crossing the northern Pacific is 

approaching the Pacific Northwest and northern CA to start the 

period. An area of elevated moisture just to the west of the CA 

coast will feed into this next s/wv trof with PW values just over 

1.00-inch helping enhance precip over northern CA and portions of 

central NV before stretching across northern NV. Freezing levels 

with this event will generally range from 4000- to 6500-feet.



As this s/wv trof moves across the area on Tuesday...look for signs 

of splitting and the southern piece forming a cutoff low somewhere 

in the vicinity of the 4-Corners region. Also...as an upr ridge 

pumps up over the eastern Pacific...this will help to amplify the 

pattern from the central Pacific all the way toward the western US 

interior. Dry northerly flow will set up across CA and NV with a 

sharp east-to-west gradient of freezing levels across the 

region...from 3000- to 5000-feet over NV and 10000-feet along 

coastal CA. 





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







AS/Kozlowski



$$