Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
200 PM EST Fri Nov 22 2024
Day 3
Valid 12Z Sun Nov 24 2024 - 12Z Mon Nov 25 2024

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

...1900 UTC Update...
No changes were made to the previous Marginal Risk area, based on
the latest (12Z) models and guidance trends.

Hurley

...Previous Discussion...
Locally heavy rain will be possible Sunday into Sunday night over
northwest CA into far southwest OR. A front slowing near the coast
will provide plentiful low level moisture convergence, and mid
level shortwave energy should provide some additional lift as well.
Moisture is a limiting factor for heavy rainfall with the better
moisture plume situated well south and not really getting drawn
into this system. Thus this is not expected to be a significant
atmospheric river, and normally would not expect a system of this
nature to pose a flood risk. However given the significant rainfall
over the past few days, this additional rainfall may be enough to
cause some localized additional flooding as the area will be more
hydrologically sensitive than normal. Still some model differences
in the exact evolution of this system and thus rainfall amounts
this period are uncertain...but current indications suggest
localized amounts of 2-3" will be possible.

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