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AGUS76 KRSA 311343
HMDRSA

Hydrometeorological Discussion
National Weather Service / California-Nevada RFC / Sacramento CA
645 AM PDT Mon Aug 31 2026

...COOLER WITH PRECIP CHANCES INCREASING OVER NORTHERN CA...

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

A weak disturbance is moving through the southwest flow aloft from a
location along the southern CA coast toward southern NV this
morning. This is expected to touch off scattered showers and
thunderstorms primarily over eastern NV during the afternoon and
early evening hours...before this s/wv trof exits the area over
northern UT. At the same time...general troffing is developing over
the northeast Pacific and is expected to dig southward along the
west coast.

An initial s/wv trof rotating through this flow will move across
northern CA on Tuesday...reaching the coast during the afternoon
hours and exiting the area over eastern OR early Wednesday. There
isn/t a lot of moisture entrained into this system...resulting in
relatively light precip over portions of northwest CA up toward the
upper Klamath River basin.

A deeper low spinning over the northeast Pacific...just off the
Pacific Northwest coast along 130W will shove a more potent moisture
plume southward toward the northern CA coast on Wednesday. Max PW
values within this feature are looking to be close to 1.50-inches.
This looks more promising for precip production for Wednesday
afternoon into Thursday with the best amounts located over the Smith
River basin with 1.00- to 2.50-inches...tapering off to 0.25- to
0.75-inch across the rest of the northern CA higher terrain...and
very little over the Sacramento Valley.

For the end of the week into the upcoming weekend...models are
hinting at tropical/monsoon moisture advecting northward from near
Baja toward southern CA. There is very low confidence in exact
placement of this elevated moisture...which may bring an increasing
chance of at least some light precip for southern CA.


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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