Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Mon Feb 16 2026
Day 1
Valid 12Z Mon Feb 16 2026 - 12Z Tue Feb 17 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
CENTRAL AND SOUTHERN CALIFORNIA...
A mid to upper-level trough will propagate into the West Coast,
while a surface wave does the same this afternoon. Showers and
scattered to isolated thunderstorms will spread south from the
central California coast this morning down to SoCal tonight. The
most impactful rainfall will likely occur between late morning and
early evening. A combination of favorable upper and LLJ dynamics
(120+ kts upper, 40-50 kts 850 mb respectively) within a
relatively moist (0.75-1" PWATs representing the 90th percentile)
and an unstable environment (100-300 J/Kg MLCAPE) will likely
produce efficient rain rates this afternoon, especially over parts
of the Central CA Coast down through the San Rafael Mountains and
northern Los Angeles metro.
HREF neighborhood probabilities indicate over a 25% chance of
exceeding 2" in 24 hours by Tuesday morning across much of the
aforementioned areas, with some embedded signals for 5"+ within
upslope areas of the Transverse Ranges and Santa Lucia Range. Burn
scars, urbanized and upslope areas will be especially susceptible
to runoff. Progressive storm motion will mitigate flash flood
risk.
Kebede
Day 2
Valid 12Z Tue Feb 17 2026 - 12Z Wed Feb 18 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF CENTRAL AND SOUTHERN CALIFORNIA...
Another mid-level trough dives south along the West Coast on
Tuesday, sending another round of showers and isolated
thunderstorms into the central and southern California Coast.
Ingredients will be less impressive on Tuesday than today, thus a
marginal risk from the Santa Cruz Mountains down through the San
Diego metro will suffice. Snow levels will also be lower so
upslope portions of the Transverse Ranges will likely see snow
where they see rain today. Saturated soils from antecedent rainfall
will be an important factor in any isolated flash flooding that
occurs within the marginal risk area.
Kebede
Day 3
Valid 12Z Wed Feb 18 2026 - 12Z Thu Feb 19 2026
...THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS
LESS THAN 5 PERCENT...
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt