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AGUS76 KRSA 061530
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
730 AM PST Thu Nov 6 2025

...ANOTHER SURGE OF MOISTURE WILL BRING ADDITIONAL MODERATE PRECIP
TO THE N COAST LATER TODAY...
...DRY CONDITIONS THEN RETURN THROUGH THE PERIOD AS HIGH PRESSURE
BUILDS IN...

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

A few light showers this morning as moisture lingers overhead. 12z
sounding out of KOAK still showing PW values at 1" and even 0.89" at
KNKX in soCal. TPW imagery shows a large area of moisture offshore
spanning the length of CA and stretching out past the Hawaiian
Islands. Over the past 12 hours observations report another 0.10-
0.75" of precip with upwards of an inch or so over Shasta. Currently
sitting under zonal flow with an upper low over the Gulf of Alaska.
A shortwave will develop on the south end of the low later this
morning with a surface low beneath it. This will push additional
moisture into nrn CA later today and tonight returning more moderate
precip to the north coast. Precip will diminish into early Friday
morning as a ridge builds in offshore. High pressure will stick
around through the weekend while another system develops on the back
side of the ridge. Models continue to show a low forming off of an
elongated trough over the Gulf into Monday. There is pretty decent
agreement on the low meandering about offshore early next week
keeping us dry. Det GFS/ECMWF then have this low weakening and
absorbing back into the main flow pattern by Wednesday. At this
point a now newly formed low will make its way towards the west
coast. Det models and a majority of ensemble members keep precip
offshore before the end of the current forecast period. There is
disagreement for the rest of Wednesday, but for this forecast expect
dry conditions to dominate after tomorrow morning.

The forecast was a blend of morning WPC guidance and the latest NBM.
Elected to use the NBM in the final time frame to omit any precip
over the coast Tuesday night as the majority of ensemble members do
not show precip reaching CA at that point. All but a few hundredths
of QPF over the next six days is expected before 12z Friday morning.
Expecting 0.50-1" or so along the north coast (locally up to 2.30"
Smith Basin/King Range), 0.25-0.75" for Shasta, 0.10-0.50" for the
rest of nrn CA north of Sonoma County, and maybe a few hundredths
to a tenth over the northern Sierra and into Sonoma County.

Freezing levels back up to 8.5-12 kft north of I-80 mid morning
gradually increasing into the weekend with most of the region above
11-12 kft by Sat am.


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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