515
AGUS76 KRSA 011510
HMDRSA

Hydrometeorological Discussion
National Weather Service / California-Nevada RFC / Sacramento CA
710 AM PST Sun Nov 1 2026

...PRECIP ACROSS EASTERN NV AND PORTIONS OF SOCAL WRAP UP TODAY...
...WEAK SYSTEM TRAVERSES NORTHERN CA AND NORTHERN NV ON TUE...
...DRY CONDITIONS RETURN TO END THE WEEK...

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

Troffing along the west coast is beginning to shift inland this
morning with the deep northern s/wv trof moving across the southern
Sierra...while the southern energy is approaching the northern Baja
coast. A rather deep moisture plume with origins in the lower
latitudes generally between 120W and 130W has been drawn northward
ahead of this overall troffing...and is advecting inland over
northern Baja on its way toward the Desert Southwest. CIMMS TPW
imagery shows values within this plume exceeding 2.00-inches as it
reaches the coast...while the 01/00Z GFS and EC both show a maximum
IVT close to 1200-kg/m/s along the Baja coast. This stream of
moisture interacting with the favorable forcing as the troffing
shifts inland is generating moderate to heavy precip downstream of
the area across AZ up into UT and CO. The western edge of the
elevated moisture will bring light to moderate precip from eastern
NV southward across portions of southern CA with anywhere from 0.50-
to 1.00-inch possible mainly through the afternoon hours. So far in
the past 3-hours since 01/12Z...the KIPL automated observation
station has seen 0.49-inch...as radar imagery shows echoes streaming
from southwest to northeast across these desert locations close to
the lower Colorado River basin.

Precip will diminish this evening and overnight as the upr trof
slides to the east and a transitory upr ridge slides across the area
on Monday. This will bring dry conditions for Day 2. Then attention
next turns to a s/wv trof moving across the eastern Pacific
generally along 40N...now just passing 150W. Models have struggled a
bit with this feature...but are starting to grasp the timing and
coverage of precip anticipated for Tuesday...which is a tad faster
than yesterday/s thinking. Precip will spread across northern CA as
the system moves inland and then weaken as it shifts inland across
northern NV. A narrowing PW plume ahead of this feature will bring
values close to 1.00-inch to the coast between Cape Mendocino and
the SF Bay Area before quickly eroding as it shifts inland. Best
precip will fall across the Eel and Russian River basins with
amounts of 0.10- to 0.33-inch...dropping off to 0.25-inch or less
for the Shasta Lake drainage and northern Sierra. The Sacramento
Valley...SF Bay Area...and central Sierra should all remain near or
less than 0.10-inch.

This s/wv trof will quickly move off toward the east and reach the
central Rockies by Wednesday. Another weak disturbance that was
initially thought to reach far enough south to bring far northern CA
and northern NV some light precip on Wednesday into Thursday is now
looking to remain too far north with dry conditions returning to the
area for the latter half of the week. High pressure will slowly
build across the west coast to end the week.


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



DRK

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