Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1100 AM EST Thu Nov 13 2025
Day 2
Valid 12Z Fri Nov 14 2025 - 12Z Sat Nov 15 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE TRANSVERSE
RANGE OF SOUTHERN CALIFORNIA...

A front will continue to make southward progress toward the
Transverse Ranges at the beginning of the forecast period, with
strong onshore flow (around 25-35 knots at 850mb) continuing to
foster upslope and orographically enhanced rainfall at 12Z Fri.
Over time though, this flow will slacken partially due to the
cutting off and retrograding mid/upper low west of the California
coast. The heavy rainfall threat will lessen substantially during
the day as a result, with only terrain-favored areas experiencing
what should be an isolated risk of excessive rainfall.
Slight Risk areas are maintained for this outlook per the previous
forecast, but have been confined to portions of Santa Barbara and
Ventura Counties for the morning rainfall activity.

Late in the forecast period, models suggest another uptick in heavy
rainfall potential approaching portions of the Los Angeles Basin
and adjacent eastern Transverse and San Diego County Mountains.
Timing on the onset of this activity is a bit uncertain, and the
bulk of this second surge of rainfall should hold until D3/Sat. A
Marginal Risk is maintained in these areas to address this
secondary threat.

Lastly, strong southwesterly flow will impinge upon the Olympics
and Cascades for a second consecutive day Friday. This
orographically enhanced heavy rain scenario will promote areas of
an additional 1-2 inches of rainfall (with locally higher totals).
With antecedent rainfall expected to fill area watersheds on
D1/Thursday, the additional rainfall could cause isolated
instances of flooding/flash flooding especially in sensitive and
low-lying areas. A Marginal Risk area has been added to account for
this threat.

Cook

Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt