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AGUS76 KRSA 031554
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
830 AM PST Mon Nov 3 2025

...LIGHT PRECIP FAR NRN CA/SRN OR MON/TUES MORNING...
...STRONGER SYSTEM WITH HEAVIER PRECIP EXPECTED LATE TUESDAY INTO
THURS MORNING ACROSS NORTHERN CA...

.METEOROLOGICAL CONDITIONS (MON AM - SUN AM)...

Wet and unsettled weather is forecast to start spreading southward
over the northern portions of the forecast area this afternoon as a
cold front and moisture plume (PWATs >1.25 inches) begins moving
onshore. Precipitation over the next 24 hours will primarily be
focused along the Coast Range and Shasta Drainage with the heaviest
accumulations (>1 inch) over Cape Mendocino and the Smith River
Basin.

Precipitation is forecast to intensify late Tuesday into Wednesday
as a deeper and broader trough swings off the coast, phasing with
the remnant moisture plume of the earlier system producing PWATs
closer to 1.5 inches across the North Coast. Heaviest precipitation
is primarily focused over similar locations to Monday with as much
as 3+ inches over Cape Mendocino and the Shasta Drainage.
Precipitation will spread southward into Thursday AM with >2 inches
along the Northern Sierra and lighter accumaltions further south.

The EC and GFS currently differ quite a bit on timing and
accumulations on Tuesday with the EC later and lighter than the GFS.
This mornings forecast primarily blended the NBM and WPC, which
increased overall accumulations slightly across northern CA,
following trends within the NBM.

Freezing levels will start the forecast period around 10k feet
across northern CA before dropping to 7k feet on Wednesday as the
trough digs southward over the region. Levels are forecast to rise
to >13k feet later in the forecast period as ridging begins to
build again.


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



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