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AGUS76 KRSA 101936

HMDRSA



Hydrometeorological Discussion

National Weather Service / California Nevada RFC / Sacramento CA

1235 PM PDT Wed Apr 10 2024



...WARMER TEMPS AND DRY CONDITIONS FOR THE NEXT COUPLE DAYS...

...LOW PRESSURE WILL BRING COOLER AND WETTER CONDITIONS BY THE 

WEEKEND...



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



After a warm next couple days with afternoon high temperatures 

running about plus 5- to plus 15-degF above normal for this time of 

year...the pattern is expected to transition as a colder system 

drops south-southeast out of the Gulf of Alaska toward the CA coast 

on Friday into the upcoming weekend. Agreement on the overall 

pattern shift is still looking good amongst the 10/12Z deterministic 

models...but the details on the trajectory of the upr low is not a 

strong point right now. The CMC continues to be closest to the 

coast...while the GFS is the farthest offshore. The EC trended just 

a tad slower and nudged to the west a bit. Still looking at enough 

disagreement that results in very little precip across northern and 

central CA (west solutions)...and widespread light to moderate 

precip across these same areas (east solutions). For now...used a 

blend of the previous forecast and the latest NBM with some manual 

edits to account for the latest EC trending slightly toward the GFS. 

This brought precip amounts down slightly for the Sierra and just a 

tick up for the coastal areas between the Russian River basin and 

the Monterey Bay area. Freezing levels above 10000-feet with the 

warm air will take on an east-to-west gradient by early 

Saturday...from 9000- to 11500-feet across NV and southern CA to 

6500- to 9500-feet across the Sierra (north-to-south) and 4000- to 

7500-feet for coastal northern/central CA.





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



Spread in the timing and inland propagation of the upper low through 

the weekend continues into the afternoon forecast with the GFS being 

slower to move the system inland. In addition to the timing 

differences, spread on the exact characteristics and details of the 

low remain resulting in uncertainties surrounding the exact 

placement of the precipitation. Afternoon forecasts generally 

followed the guidance from the WPC, which primarily leaned on the 

EC/UKMET/CMC and the 06Z GFS through day 5. Accumulations decreased 

slightly along the coast (generally <0.10 inches) while increasing 

up to a quarter of an inch over the eastern Transverse in Los 

Angeles and San Bernardino Counties. Little to no change elsewhere. 

Ridging is forecast to build over the forecast area as the upper-low 

moves inland, resulting in warmer and drier conditions. 



Freezing levels are forecast to lower to below 4,000 feet along the 

coast as the core of the upper low moves inland before rising under 

ridging to >10,000 feet across the south and >4,000 feet across the 

north on Monday. 





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







Kozlowski/CH



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