775
FXUS66 KEKA 072112
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
212 PM PDT Mon Jul 7 2025

.SYNOPSIS...Slightly cooler temperatures are expected Tuesday and
Wednesday. Warming is expected again Thursday with additional
warming Friday with the heat continuing into the weekend.

&&

.DISCUSSION...An area of low pressure is approaching from the west
this afternoon. This has brought a southerly surge of stratus and
southerly winds along the coast. This is also bringing some cooler
air aloft and generating some instability. This may allow a few
thunderstorms to develop this afternoon and evening. The majority
of the activity is expected to be in Siskiyou county. However a
few of them could develop in northern Trinity county mainly over
the higher terrain. With a westerly storm motion these may push
into Del Norte county this evening, but confidence is low on this.

Tonight and Tuesday a deeper marine layer is and more widespread
stratus is expected as the upper level low continues to approach
the area. This is expected to bring some cooler temperatures,
especially in the near coastal areas. This is expected to continue
into Wednesday. This has the potential to bring a thunderstorm or
two,

High pressure builds back into the area Thursday, bringing hot
temperatures back into the interior. NBM probabilities of seeing
over 100 degrees is around 50%-60% Thursday for most interior
valleys. Probabilities increase to over 90% by Friday with around
50% probabilities of 105 or greater. Widespread moderate to locally
major HeatRisk is expected, meaning heat will be dangerous to those
sensitive and without sufficient cooling. Ensembles are showing high
probabilities for high pressure to remain over the area through at
least early next week, with triple digit temperatures remaining
possible. MKK/JB

&&

.AVIATION...Persistent southerlies are driving marine stratus up the
north coast, bringing IFR to LIFR ceilings to the coastal terminals.
A brief period of scattering is possible this afternoon as cloud
cover retreats to the immediate coastline, but will be shortlived if
verified. Gusts 15 to 20 knots possible at CEC this afternoon and
lee of other coastal headlands. UKI will experience similarly gusty
conditions this afternoon. IFR stratus expected to return after 03Z
this evening as southerly flow continues to drive the cloud deck
into the coast. Model soundings indicate a strong inversion keeping
ceilings <1000 feet with reduced visibilities likely overnight (HREF
50 chance <1 sm through 15Z). With strong southerly flow, there is
also a chance of stratus reaching UKI up the Russian river valley
around sunrise (around 20%).

&&

.MARINE...Steep wind waves are still being observed in the inner
waters this afternoon as northerly winds gradually migrate further
offshore. Gentle to moderate southerly breezes will continue in
areas adjacent to the coast, especially lee of coastal headlands.
Conditions will continue to diminish this afternoon and overnight as
a closed upper low cycles off the CA coast. Winds and seas will
remain especially calm Tuesday through late Wednesday as a small
southerly swell fills into the waters. Another period of strong
northerlies is likely mid to late week as high pressure builds in
from the SE. NBM and mid range model guidance shows 50 to 60% chance
of gale gusts developing in the outer waters beginning early
Thursday.

&&

.FIRE WEATHER...Warm temperatures and low afternoon humidities
continue today, with slightly lower temperatures expected Tuesday
and Wednesday. Overnight recoveries generally remain good aside
from the exposed ridges in the thermal belt. There is a slight
chance (15%) for thunderstorms this afternoon and evening. These
are mainly expected to be in Siskiyou county, but there may also
be some in northern Trinity county. A few may also drift west into
Del Norte county this evening. Any that do form are expected to
bring a few dry lightning strikes and gusty, erratic winds.

Much hotter temperatures and drier humidity are likely in the
interior late this week. Triple digit temperatures are likely in
most of the interior valleys by Friday with very low afternoon
RHs and moderate overnight recoveries. MKK

&&

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

     Small Craft Advisory until 8 AM PDT Tuesday for PZZ470-475.

&&

$$

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