Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
248 AM EST Sat Nov 23 2024
Day 3
Valid 12Z Mon Nov 25 2024 - 12Z Tue Nov 26 2024

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
NORTHERN CALIFORNIA INTO FAR SOUTHWEST OREGON...

Showery conditions will likely continue across portions of northern
CA and southwest OR Monday into Monday night as a deep layered low
and shortwave energy moves inland. Certainly not a classic setup
for flooding with limited moisture and dropping IVT
values...however this area remains more hydrologically sensitive
than normal following the significant atmospheric river event the
past few days. Additional rainfall over far northwest CA into
southwest OR is generally 1-3" in the guidance, with isolated
totals of this magnitude also possible over the western slopes of
the northern Sierra Nevada.

A more significant plume of moisture/IVT will actually move into
portions of southern/central CA...generally from portions of San
Luis Obispo and Monterey counties into the western slopes of the
southern Sierra Nevada. QPF has been trending up with this system,
although still seeing some model spread. The latest model consensus
suggests a possible 2-3" of rain along the coastal ranges and the
southern Sierra below snow levels. Not seeing any instability with
this system and large scale forcing is only modest, so hourly
rainfall rates are generally not expected to exceed 0.5". Given
this, and the fact that most of this area has not seen significant
rainfall recently, will continue with no areas in the excessive
rainfall outlook for now.

Chenard
Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt