583
FXUS66 KEKA 120712
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1212 AM PDT Sat Sep 12 2026

.KEY MESSAGES...

* Red Flag Warning in effect for all towns and areas within Lake
  County Saturday for critical fire weather of strong winds and low
  relative humidity.

* Elevated fire danger each afternoon through Saturday for the
  interior.

* Chances for light rainfall for Del Norte and northern Humboldt
  Saturday.


&&

.SYNOPSIS...Cooler temperatures are expected through into the
weekend. Light rain is possible for the Del Norte and northern
Humboldt Saturday. Westerly to northwesterly winds will bring
elevated to critical fire danger for the interior Saturday.


&&

.DISCUSSION...A trough and associated front will enter the area
today, considerably lowering interior temperatures to the 70s and
80s. The front will also bring a chance for rain to Del Norte and
northern Humboldt Counties. Del Norte has around an 80-90% chance to
see measurable rain, while northern Humboldt has around a 20-40%
chance, mainly north of Eureka. The chance for wetting rain (over
0.1") is around 10-20% in northern Humboldt and 60-70% in Del Norte.
There is some instability modeled with this system, which may allow
for a thunderstorm to develop in an especially strong shower.

Post frontal westerly winds will strengthen this afternoon for the
eastern portions of the area. The probability of wind gusts over 30
mph are above 50% for much of eastern Lake County, eastern
Mendocino, and the Trinity River Valley in eastern Trinity County.
This will elevate fire weather concerns, particularly over Lake
County where the strongest winds will coincide with dry conditions.
A Red Flag Warning is in effect for Lake County today, but elevated
fire weather conditions will exist for all the interior areas listed
above. There are also chances this fire threat continues Sunday
night and Monday for the far eastern portions of the area. See the
Fire Weather section below.

An omega-block pattern is likely to develop right off the Pacific
Northwest coast, with troughing remaining far east and far west.
Slightly over half of ensemble members do show an elongated
positively tilted trough or cutoff low over the area Wednesday.
This will contain little moisture and may only result in a slightly
deepened marine layer and perhaps some modest instability in the
higher terrain. Regardless, a dry, near-normal pattern looks likely
for the following week as the omega block stalls any storm track for
NW California. /JB


&&

.AVIATION...Nighttime IR Satellite Imagery shows a weak stratus deck
developing along the Del Norte coastline. This feature is keeping
the forecast optimistic for VFR through the early hours of the
morning for much of the North Coast. Light winds are expected
through the morning before westerlies at ACV and southerlies at CEC
form. Inland, WNW winds will funnel through terrain with heightened
chances for gusts in Mendocino and Lake County, especially near
elevated terrain. VFR is expected in areas away from smoke from the
Lucas Fire in Lake County. Rainshowers are possible for Del Norte
and N. Humboldt Co, yet models show continued VFR ceilings with
periodic MVFR possible.


&&

.MARINE...An incoming upper level through is ushering a weak cold
front to the coastal waters by tomorrow. This front will weaken the
surface pressure gradient allowing for the weakening of northerly
winds through the overnight hours. Localized areas, such as those
downwind from points or capes can expect northerlies to last
slightly longer. Gentle breezes expected through Saturday with
gentle to moderate breezes. Fresh to strong northerly breezes return
Sunday and continue through early next week. Near-gale force gusts
possible south of Cape Mendocino Monday.


&&

.FIRE WEATHER...A troughing pattern will bring breezier winds,
much cooler temperatures, and a deeper marine layer through the
weekend. Wetting rain is possible for Del Norte and far northern
Humboldt. Stronger winds are forecast this afternoon with gusts up
to 35 mph are possible in Lake, southern Mendocino, and eastern
Trinity Counties, especially for higher, N-S orientated terrain. RH
will rise with this onshore push of winds to the 20s and 30s, but
much stronger wind gusts of 25 to 35 mph will support critical fire
weather conditions, particularly in Lake County. In the few hours
before the winds increase, hot and dry conditions are possible,
increasing the likelihood of critical fire weather conditions for
Lake County. A Red Flag Warning has been issued in Lake County from
10 AM Saturday to 2 AM Sunday. Other areas outside Lake County will
still see elevated fire danger, including eastern Mendocino and
Trinity County, despite not being within the Red Flag Warning area.

Winds ease Sunday and RHs increase slightly into the high 20s to the
high 30s for the eastern interior. Areas closer to the coast could
see afternoon RHs in the 50s with a much deeper marine layer. Sunday
night into Monday, an increase of northerly winds down the Central
Valley of California may elevate fire conditions again for the
eastern portions of the area, particularly eastern Lake County
should the winds end up on the stronger end. RH does trend upwards,
so the threat may be muted somewhat, but it is something to watch.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Red Flag Warning from 10 AM this morning to 2 AM PDT Sunday
     for CAZ418>421.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PDT early this morning for
     PZZ455-475.

&&

$$

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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https://www.weather.gov/images/eka/zonemap.png