373
FXUS66 KEKA 122308 AAA
AFDEKA

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Eureka CA
408 PM PDT Fri Jun 12 2026

.KEY MESSAGES...

-  Temperatures will warm quickly with moderate to major HeatRisk
expected through the weekend and into early next week.

-  Coastal stratus is possible tonight south of Cape Mendocino.

-  Potential cooling trend in the inland areas starting on Wednesday.

.SYNOPSIS...High pressure continues to build into the area with
hot temperatures expected into early next week. The near coastal and
coastal areas may start to see more marine influence over the
weekend and into early next week while Trinity county is expected to
see the hottest temperatures Monday and Tuesday. Cooler temperatures
are possible starting on Wednesday.


&&

.DISCUSSION...High pressure continues to build in across the area
and the interior is expected to see a few hot days of this heatwave.
A southerly surge of clouds could make its way up to Ukiah but the
likelihood of that depends on available moisture at low levels and
advected stratus into the Russian River Valley and Anderson Valley.
This will likely start to cool temperatures at the immediate coast
and inland to areas as far as Boonville or so.

For the weekend a weak upper level trough is expected to drop down
from the north. This is expected to bring some instability, but
current moisture profiles look like they remain too dry for any
thunderstorms. Temperatures are expected to remain more steady
fluctuating somewhere around 100 in the afternoons. The winds
southerly winds along the Mendocino coast are expected to slightly
increase and keep the stratus in place. The high pressure is
expected to keep the marine layer fairly shallow and it may mix out
each afternoon. Sunday it looks fairly certain that the marine layer
will be well north of Cape Mendocino as the winds get lighter.

Heat Advisories have been hoisted beginning Saturday when
temperatures noticeably increaser in combination with warmer
overnight low over the interior. Advisories expand in coverage
southward Sunday. Monday and Tuesday high pressure continues to
the strengthen over the area and is expected to some of the
hottest temperatures of this heat wave. Further expansion
southward or westward closer to the coast may be required.

Wednesday the high pressure is expected to start to break down and
cooler temperatures are expected aloft. This will cool temperatures
across the area and likely deepen the marine layer.
MKK/JJW


&&

.AVIATION...VFR conditions remain firmly in place. Northwesterly
winds are breezy along the coast. Surface winds will ease into the
weekend. A week area of low pressure is ushering in southerly flow
along the Mendocino coast, and stratus was observed slowly pressing
northward Friday afternoon. Guidance is struggling to model much of
it make it around the cape, but the subtle increase in low level
moisture should allow for at least localized shallow stratus
formation around Humboldt Bay. Probability for this scenario has
increased to 40 to 50% after 12Z Saturday. Given the building
ridge, fog visibilities will be possible. The shallow ceiling
levels will also allow for quick scattering. If stratus does make
it around the cape Saturday, clearing may be delayed due to light
westerly flow.


&&

.MARINE...Gale strength northerlies persist in the northern
waters beyond 10 nm in Zone 470. Seas up to 14 ft are likely
occurring over this zone as a result. Advisory level conditions
remain elsewhere from steep wind-driven seas and northerly winds of
20 to 25 kts. Steep seas are propagating into the northern inner
zone 450, but the inners south of Cape Mendocino remain more
sheltered from the larger northwesterly seas. Winds and seas will
diminish Sunday. A small long period southerly swell moves in Monday
while northerlies and short period seas restrengthen.


&&

.FIRE WEATHER...Temperatures are expected to remain hot and dry
into early next. Over the weekend a shortwave moving down form the
Pacific Northwest is expected to increase instability and this may
lead to increased mixing heights. It doesn`t look like there will
be enough moisture in NW California for any thunderstorms, that is
expected to remain well east and south of the area. Early next
week temperatures may climb slightly more and the hottest
temperatures of the heat wave are expected. Wednesday into late in
the week cooler temperatures are expected. This may also bring
stronger winds or possibly thunderstorms depending on how the
pattern evolves. MKK.


&&

.COASTAL FLOODING...High astronomical tides are predicted from
Saturday, June 13 through Tuesday June 16 for Northwest
California. The combination of a high astronomical tides and long-
period swells will increase the risk of minor coastal flooding
around Humboldt Bay, including King Salmon and low-lying roads
near Arcata Bottoms. Advisory level tidal heights of 8.8 ft at the
North Spit gauge may come close to being met at the 9:53 pm high
tide Friday. There is higher confidence on 8.8 to 9.1 ft tides
occurring Saturday through Tuesday. /JJW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Heat Advisory from 11 AM Saturday to 10 PM PDT Tuesday for
     CAZ102-105-116.

     Coastal Flood Advisory from 9 PM to 11 PM PDT Saturday for
     CAZ103.

     Heat Advisory from 11 AM Sunday to 10 PM PDT Tuesday for
     CAZ108-111-117.

     Heat Advisory until 10 PM PDT Saturday for CAZ113-114-
     118>120.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Coastal Flood Advisory from 9 PM to 11 PM PDT Saturday for
     PZZ415.

     Small Craft Advisory until 9 PM PDT Saturday for PZZ450-475.

     Gale Warning until 9 PM PDT Saturday 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