Crescent City, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

257
FXUS66 KEKA 252107
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
207 PM PDT Fri Jul 25 2025

.SYNOPSIS...Thunderstorms are possible through late tonight. Near
normal to slightly below normal temperatures expected for the next
few days. Temperatures trend slightly upward towards the later
parts of next week.


&&

.DISCUSSION...Early this morning around 13z, a small cell of
convective thunderstorms moved through interior Humboldt near
Bridgeville and continued on a southwest trajectory before
fizzling out. The ingredients for convective weather continues
through the afternoon and well into this evening. As of 2030z,
cells have popped up in the Trinity Horn and south of the Yolly
Bolly district near the southeastern Trinity/Tehama border. With
PWAT values near 1.0-1.2 and EQL levels showing elevated CAPE, we
are expecting convective activity through late tonight which also
includes small hail and the possibility of strong outflow winds
of up to 50+mph as the high based thunderstorms drop out. A
progression from the northeast to southwest has the steering and
flow hinting at movement into Lake or eastern Mendocino counties.
In general, the upper-low inches more northeasterly, bringing a
similar setup to yesterday, but moves slightly south and east.
Confidence has increased on thunderstorms forming across Trinity
County, eastern Mendocino, and northern Lake Counties. CAPE may be
even higher (nearing 1000 J/kg) with DCAPE remaining near 1000
J/kg. Higher shear in the Yolla Bollys may allow for some longer-
lasting storms, but elsewhere shear remain weak. Storms will
likely form and collapse quickly, bringing gusty outflow winds.
The previously mentioned high PWATs of an inch or more could
support periods of heavy rain.

The low moves to the east Saturday, bringing most mid-level moisture
with it. Thunderstorm chances significantly decline, and if any
form, the Trinity Horn is the most likely area. Sunday and into the
middle of next week high pressure is expected to generally remain
east of the area. This will keep temperatures near seasonal normals
with highs in the upper 80s to low 90s. Thunder potential generally
looks to remain low. Ensembles are hinting at another upper-low
forming right off the coast, which may return thunderstorm chances
mid next week, and this will need to be watched.


&&

.AVIATION...(18Z TAFs) IFR conditions remain through the morning
along the coast. Through the day cloud ceilings are likely (70-90%)
to scatter away  to as daytime mixing takes effect around 21-02Z to
give MVFR/VFR conditions. IFR conditions (60-80%) expected to return
and remain through tonight and tomorrow morning. Probabilities for
LIFR conditions are 30-40% and are not expected for coastal areas.

Inland, river valley clearing will lead to VFR conditions. A
thunderstorm threat this afternoon is possible in eastern Humboldt,
NE Mendocino, & Trinity county with NBM showing (a 30-40%
probability of lightning from 21Z-06Z today. Calm conditions
expected late tonight through the morning inland.



&&

.MARINE...An upper level cutoff low will lurk off the Central
California Coast and will remain in the vicinity through Friday and
develop into an open upper level trough for the weekend. This will
continue to keep the surface pressure gradient, holding winds to
gentle to moderate levels through the weekend. Seas 2 to 5 feet are
expected, with the lightest conditions expected nearest the coast.
Winds are expected to be mostly northerly with south/southwest winds
likely directly adjacent to the coast, especially overnight as
southerly reversals form. The northerlies will be slightly stronger
today , mainly through the southern outer zone, with sustained winds
likely remaining mainly below 20 kts through the weekend, except for
a small localized area south of Cape Mendocino where wind gusts will
increase to 20 to 25 KTS from the north/northwest. Wind waves are
forecasted to increase slightly during the daytime areas in this
area as well. MH/DS

&&

.FIRE WEATHER...Friday, isolated to scattered thunderstorms shift
south and east with the highest confidence in Trinity, eastern
Mendocino, and northern Lake. Isolated storms are possible in
eastern Humboldt, as well. Again gusty, erratic outflow winds of
50 mph are possible and a brief heavy downpour is not out of the
question. A Red Flag Warning has been issued for abundant
lightning in Trinity, eastern Mendocino, and northern Lake
Counties. Thunderstorm chances decrease this weekend.

Outside of thunderstorms, winds are generally expected to be fairly
light and terrain driven. Interior Temperatures are generally
expected to be around or slightly below seasonal normals with highs
in the 80s to low 90s. Dry afternoon RHs in the 20s are possible in
the eastern portions of the area, but good overnight recoveries are
likely. JB



&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Red Flag Warning until 11 PM PDT this evening for CAZ212-
     277-283.

NORTHWEST CALIFORNIA COASTAL WATERS...
None.
&&

$$

NOTE: The full forecast discussion is now regularly issued between
10 am/pm and 1 pm/am. Additional updates will be issued as needed.

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