879
AGUS76 KRSA 201547
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
750 AM PST Thu Nov 20 2025

...SHOWERS AND OCCASIONAL T-STORMS TODAY AS A FRONT SWEEPS THROUGH
CA FOLLOWED BY AN UPPER LOW ALONG THE COAST...
...LINGERING SHOWERS OVER SRN CA TOMORROW AS THE SYSTEM EXITS
FOLLOWED BY MOSTLY DRY CONDITIONS THE REST OF THE PERIOD...

.METEOROLOGICAL CONDITIONS (THU AM - WED AM)...

A front is currently stretched across nrn/cntrl CA and out to the
Pacific as an upper low forms off the coast of the PacNW. Radar has
some showers just south of I-80 and into SLO county. Observations
overnight report about 0.10-0.75" over nrn CA, locally 0.75-1" over
Shasta, and 0.10-0.50" around the Bay Area/central coast. Expect
showers to continue today as the front sweeps across the state re-
enforced by the trailing upper low. The low is forecast to move along
the CA coast later today reaching Point Conception early tomorrow
morning. As the low passes, some instability may result in
thunderstorms. Both the GFS and ECMWF continue to take the low south
offshore on Friday before taking its turn eastward towards land in
the evening after passing the southern border. This will allow
showers to linger over srn CA through much of Saturday as it slowly
exits into AZ. QPF through 00z Sun: 0.75-2.50" Transverse, 0.50-
1.50" coastal soCal, 0.10-0.50" down the valleys, and 0.25" or less
for the central coast/Bay Area. Precip has now mainly pulled out of
nw CA so just some light lingering showers.

Mostly dry conditions are expected the rest of the period aside from
occasional showers along the northern regional border as a couple
troughs move through the PacNW. For now the systems look to be too
far north to reach CA but that could change. Only about a hundredth
of an inch or so for the Smith Basin in the extended and up to 0.10"
for the srn OR Cascades, otherwise dry weather expected.

Freezing levels 5.5-8 kft across the Sierra this morning gradually
rising overnight up to 6.5-8.5 kft as the system gets further away.
Trend of higher freezing levels through the weekend back up to 8-11
kft into Saturday with the southern Sierra hitting 12.5 kft Monday.


Please Note: This product may NOT be routinely updated.
Please refer to the following product issued by the CNRFC
www.cnrfc.noaa.gov/Daily-Briefing for a graphical summary of
weather and hydrologic conditions.

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



AS

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