650
FXUS66 KEKA 132013
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
113 PM PDT Mon Oct 13 2025

.SYNOPSIS...An area of low pressure continues to push southward
pulling the precipitation with it. There will be chances for
interior frost this week. Temperatures will warm later this week
as high pressure builds back in.


&&

.DISCUSSION...The bands of heavy rainfall and gusty winds observed
this morning have passed as an area of low pressure pulls southward.
Wraparound moisture will continue the rainfall and some higher
elevation mountain snow chances today. Periods of moderate rainfall
can be expected south over Mendocino and Lake counties through
this evening. There will be extended chances for showers through
the interior southern zones on Tuesday, mainly over Trinity County
and southward as the low stalls over CEN CA before weakening and
ejecting east. Convective allowing models (CAMs) resolved some
stronger terrain enhanced showers Tuesday afternoon over the
eastern portions of the far interior mountains Tuesday afternoon.
There may be enough instability for a couple thunderstorms over
the high terrain from Southeast Trinity south into far interior
Lake County briefly Tuesday afternoon.

Overnight temperatures will lower tonight with the passage of a
front. There will be a battle to attempt to dry the lower levels
as breezy offshore winds develop while cloudcover and showers
remain. Some areas of frost may develop, but coverage looks
limited at this time given the lingering unsettled weather.
Tuesday night will have to be reexamined if confidence for drying
and clearing is higher.

High pressure will expand in from the west through the latter
portion of the week and into the weekend. Above normal temperatures
are forecast over this period with strong chances (70-80%) for
the warmer interior valleys to reach or exceed 80F. Rain chances
increase again through the latter half of the weekend. JJW


&&

.AVIATION...A cold front is moving across the area this afternoon.
It has generally moved past the coastal terminals and VFR conditions
are in place. This continues to bring periods of rain and IFR
conditions to Trinity, Mendocino and Lake counties this afternoon
and overnight. Behind the front showers are developing and may bring
occasional showers and brief IFR conditions are possible in the
heavier showers. As the showers come to a end behind the front low
level clouds are expected to settle into the inland valleys bringing
IFR or LIFR conditions. Offshore flow at the coast is generally
expected to keep the clouds away, although few brief periods of
ground fog are possible. Showers may linger through the night in
Mendocino and Lake counties as the upper level low moves overhead.
Tuesday there may be a few lingering showers in southern Mendocino
and Lake counties. MKK


&&

.MARINE...Winds have generally become northerly across the waters
behind the front this afternoon and are starting to strengthen. The
18Z ASCAT pass shows 15 to 20 kt winds in most areas aside from
inside 10 NM north of Cape Mendocino. The winds are expected to peak
around 15 to 25 kt this afternoon and evening before diminishing
again overnight.  Showers and a few thunderstorms are possible this
afternoon and tonight as the upper level low starts to move
overhead. Waves are dominated by a northwest swell expected to
build to around 10 to 11 feet at 10 seconds or so. This is expected
to start diminishing tonight. In general have gone slightly over the
model guidance with this wave coming in higher than expected. In
addition to this swell, short period wind driven waves are expected
to peak around 5 to 7 feet.

Tuesday northerly winds remain stronger beyond 20 NM and start to
become southerly close to the coast as the upper level trough pulls
out of the area. These remain lighter on Wednesday before
strengthening again on Thursday and Friday. Saturday winds are
expected to start diminishing again ahead of the next weather system
on Sunday. Tuesday a long period swell starts to build in. Initially
it is expected to be around 3 feet at 16 seconds and that is also
expected to be it`s peak. Otherwise waves are expected to be steep
and wind driven. MKK


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 5 AM PDT Tuesday for PZZ450.

     Small Craft Advisory until 3 PM PDT Tuesday for PZZ455-475.

     Small Craft Advisory until 3 PM PDT Tuesday for PZZ470.

&&

$$

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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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png