Frost Advisory 10, NWS Eureka, CA

935 
WWUS76 KEKA 130532
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1032 PM PDT Sun Apr 12 2026

CAZ110-111-114-131500-
/O.CON.KEKA.FR.Y.0010.260413T0900Z-260413T1500Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
Including Potter Valley and Gravelly Valley Airport
1032 PM PDT Sun Apr 12 2026

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 8 AM PDT MONDAY...

* WHAT...Temperatures as low as 35 will result in frost formation.

* WHERE...Northern Mendocino Interior, and Northern Lake.

* WHEN...From 2 AM to 8 AM PDT Monday.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive
  outdoor plants may be killed if left uncovered.

* ADDITIONAL DETAILS...Some valleys may see fog instead, which will
  reduce the risk of frost.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka

MKK

580 
WWUS76 KEKA 130715
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1215 AM PDT Mon Apr 13 2026

CAZ115-131500-
/O.EXA.KEKA.FR.Y.0010.260413T0900Z-260413T1500Z/
Southern Lake-
Including Middletown, Clearlake Park, Clearlake, Finley, Lakeport,
and Hidden Valley Lake
1215 AM PDT Mon Apr 13 2026

...FROST ADVISORY IN EFFECT UNTIL 8 AM PDT THIS MORNING...

* WHAT...Temperatures as low as 33 will result in frost formation.

* WHERE...Southern Lake.

* WHEN...Until 8 AM PDT this morning.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive
  outdoor plants may be killed if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

CAZ110-111-114-131500-
/O.CON.KEKA.FR.Y.0010.260413T0900Z-260413T1500Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
Including Potter Valley and Gravelly Valley Airport
1215 AM PDT Mon Apr 13 2026

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

* WHAT...Temperatures as low as 33 will result in frost formation.

* WHERE...Northern Mendocino Interior, and Northern Lake.

* WHEN...Until 8 AM PDT this morning.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive
  outdoor plants may be killed if left uncovered.

* ADDITIONAL DETAILS...Some valleys may see fog instead, which will
  reduce the risk of frost.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka

MKK

530 
WWUS76 KEKA 131448
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
748 AM PDT Mon Apr 13 2026

CAZ110-111-114-115-131600-
/O.EXP.KEKA.FR.Y.0010.000000T0000Z-260413T1500Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-Southern Lake-
Including Lakeport, Finley, Gravelly Valley Airport, Hidden Valley
Lake, Middletown, Clearlake, Potter Valley, and Clearlake Park
748 AM PDT Mon Apr 13 2026

...FROST ADVISORY WILL EXPIRE AT 8 AM PDT THIS MORNING...

The threat has ended.

$$

For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka

JB

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1250 AM PDT Sun Apr 12 2026

.SYNOPSIS...Scattered showers are expected again today with a
slight chance for thunderstorms, mainly in the afternoon. Cool
temperatures and a mix of sun and clouds are expected Monday and
Tuesday. Rain is expected Wednesday, mainly north of Mendocino
county. Near freezing or freezing temperatures are expected late
in the week with more rain possible over the weekend.

&&

.DISCUSSION...The upper level low is moving onshore this morning
and continuing to bring showers and a few thunderstorms to the
area. Snow levels are around 3,500 to 4000 feet with some local
areas of snow down to 3,000 feet. Generally accumulations look to
only be a few inches of slushy snow below 5,000 feet with larger
amounts at higher elevations. This afternoon with the daytime
heating and the upper level low moving overhead the models are
showing a 100 to 200 j/kg of CAPE and this may be enough to bring
some more thunderstorms to the inland areas. This will depend on
how quickly the low moves out of the area and there is still some
uncertainty on that. Snow levels are also expected to rise this
afternoon with daytime heating and as the low moves out. As the
low moves overhead and then out of the area winds are expected to
remain lighter than yesterday.

Sunday night into Monday with the low moving out is is expected
to start drying out. However, now some of the models are showing
a shortwave moving down from the north and this may bring some
more light rain or drizzle on Monday. Very little rainfall is
expected, generally less than a tenth of an inch. However, this
will likely bring enough clouds to keep temperatures in the
northern valleys above freezing. Farther south skies are expected
to remain more clear in Mendocino and Lake counties, although some
fog may form in the valleys due to the recent rain. This could
allow some frost to form and a frost advisory may be needed. Monday
afternoon temperatures will generally stay in the 50s with some
low 60s possible in southern Mendocino and Lake counties. Monday
night into Tuesday is expected to remain dry. Frost is possible
in more of the area, but there still may be some clouds and valley
around, especially in the north. Tuesday afternoon temperatures
may finally warm into the 60s in many of the valleys, although the
coast will likely remain in the 50s.

The next weather system is expected to bring more rain Tuesday
night into Wednesday. Rainfall amounts continue to increase,
although probabilities drop off quickly in Mendocino and Lake
counties. The Del Norte mountains have around a 50 percent chance
of seeing 1 inch, however the mountains of Humboldt county only
have around a 10 percent chance of seeing over an inch. Humboldt
and Trinity counties are expected to see around a quarter to a
half inch of rain. Northern Mendocino county is expected to see
less than quarter of an inch with only a trace to a tenth of an
inch farther south. Snow levels are mainly expected to be around
5,000 feet.

Thursday through early Saturday mainly dry weather is expected
and afternoon temperatures will warm into the 60s and 70s once
again. It looks like the valleys will finally dry out enough to
allow temperatures to cool, especially Thursday morning. Overnight
lows are expected to be near or below freezing. There may even be
frost along the coast.

Next weekend there is the potential for another round
of rain. Currently it looks like the rain will start to spread
across the area Saturday night and continue on Sunday. MKK

&&

.AVIATION...(06Z TAFs)...Swaths of moderate to heavy rain over the
CWA Saturday late afternoon into the evening brought periods of LIFR
and reduced visibility. Intensity has waned with post frontal winds
light and variable as of 05z. VFR/MVFR conditions for mostly all
terminals in the CWA are expected through the TAF period with cloud
cover dropping off after 07z. Cyclonic flow continues as the CCW
motion, centered off of Cape Mendo, lumbers northward up the
coastline. Ceilings around 5000 feet or more could come down to
around 2500 feet by Sunday morning sunrise hours, MVFR conditions
with light rain with sporadic infrequency expected. Chances for rain
drop off by the late afternoon Sunday for the coastal terminals with
a return overnight into early Monday morning. /EYS

&&

.MARINE...West to northwest winds will develop early Sunday.
In addition there is expected to be a west-northwest swell around
5-7 feet at 9-10 seconds and some additional small swells through
the day on Sunday.

Monday, northerly winds returns as high pressure starts to build
into the area. This will promote moderate to fresh northerly breezes
across the waters Monday through Tuesday, with the strongest winds
south of Cape Mendocino. Wednesday, a brief wind shift to the south
is expected over the northern waters as a frontal system moves
through, followed by strengthening northerly winds Wednesday night
through Friday as the pressure gradient tightens. There is a
potential (75-95% chance) of gale force gusts late next week.
/ZVS

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Winter Weather Advisory until 11 PM PDT Sunday for CAZ107.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until midnight PDT tonight for PZZ450-
     455-470-475.

&&

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