Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
423 PM EDT Mon Oct 13 2025
Day 2
Valid 12Z Tue Oct 14 2025 - 12Z Wed Oct 15 2025

...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL OVER PORTIONS OF
SOUTHERN CALIFORNIA...

2030Z Excessive Rainfall Discussion Update...

Few changes needed to the previously-issued ERD. Present thinking
is that the main threat for excessive rainfall across California
will be in the first 12 hours of so given the progressive nature of
the anomalous upper low dropping southward along the coast.
Elsewhere...the large scale features were handled similarly
amongst the various models.

Bann

0830Z Excessive Rainfall Discussion...

...Central to Southern California...

Our western disturbance will continue its progression slowly inland
with a steady south-southwesterly component situated over the
terrain of southern CA. Expect a continuance from the D1 to bleed
into the first half of D2 with heavy rainfall aligned within the
eastern Transverse Range and the northern Peninsular Range to the
north and northeast of Los Angeles. PWAT anomalies on the order of
1-2 deviations above normal are sufficient for a deep layer
moisture regime capable for heavy rainfall rates between 0.5-1"/hr
with a chance for a few stronger cores to exceed 1"/hr, a signal
more than capable of producing flash flooding in-of the area most
susceptible given the burn scar remnants positioned in the
Peninsular Range. Additional totals of 1-3" are forecast with
locally higher possible in those areas northeast of Los Angeles in
the terrain. Totals for the event will run between 1-4", plentiful
over a span of 12-24 hrs. to cause issues in what is a sensitive
locale for flash flooding and debris flow. The previous SLGT risk
was linked together and spans the eastern Transverse into the
northern Peninsular Range. MRGL risk is in place surrounding,
including an extension into parts of the Central Valley and
adjacent Sierra Foothills as locally heavy rainfall is still
forecast through the first 6-12 hrs. of the period which could spur
some isolated flash flood signals.

...New Mexico and West Texas...

Remnant elevated moisture across far west TX into NM within a
persistent axis of diffluent flow will yield a period of scattered
thunderstorms over the two areas leading to isolated flash flood
concerns, mainly in urban zones and over the complex terrain
aligned from the Sacramento's up into the Sangre de Cristos. Totals
are not very appreciable at this juncture, but environmental
conditions still support some heavier rainfall prospects over areas
that will have seen a decent amount of rain leading in. Combination
of antecedent conditions and additional rainfall place the threat
inside the MRGL risk threshold leading to general continuity from
previous forecast.

Kleebauer


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