358
FXUS66 KEKA 060716
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1216 AM PDT Sun Jul 6 2025

.SYNOPSIS...Temperatures continue to increase through Monday in the
interior. There is a slight chance for interior thunderstorms Monday
and Wednesday along with slightly cooler temperatures. Hot weather
with temperatures over 100 degrees possible by Thursday.

KEY MESSAGES:
* Warmer interior temperatures today and Monday

* Slight chance of interior thunderstorms Monday and Wednesday

* Hot temperatures with Moderate HeatRisk Thursday into next
  weekend


&&

.DISCUSSION...High pressure continues to build in to our east while
a cutoff low forms off the coast of northern California. Warmer high
temperatures are expected today and Monday with 90s likely in most
valleys. Triple digits are not out of the question in the warmest
valleys, including the Trinity River valley. The upper low off the
coast moves closer early in the work week. High temperatures are
forecast to lower 5-10 degrees, closer to seasonal normals.

Moisture associated with the upper low along with still warm
temperatures does bring a slight chance for thunderstorms in the
higher terrain of northern Trinity county. CAMs within range of
Monday afternoon are showing most activity to the northeast of the
area, but still there is a 10-15% chance. Subtle changes in the
position of the low will determine if there is enough moisture
available for convection and where it will occur, so this will need
to continue to be monitored. Confidence is lower Tuesday afternoon
as the low (and any possible thunder activity) moves northward. The
low moves onshore and passes through the area Wednesday, which does
increase thunder chances slightly in Trinity County, but confidence
remains low.

High pressure builds back in Thursday and Friday, 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 80% by Friday with around
50% probabilities of 105 or greater. Widespread moderate to locally
major HeatRisk is expected which will be dangerous to those
sensitive to heat and those without sufficient cooling. JB


&&

.AVIATION...Coastal terminals have maintained VFR conditions as of
20z today. Partly cloudy skies with less than 1000ft ceilings are
around 60% likely at filling back in for KACV by midnight. Ceilings
and visibility will further degrade into the early morning hours,
with less than 500ft at 65% probability. Similar conditions at KCEC
overnight and into Sunday morning. Light southerly winds at KUKI by
late morning will become variable, westerly at times and build to
around 5kts or so. VFR at KUKI will be the prevailing condition.


&&

.MARINE...Northerlies with gusts 20 to 30 knots developing in the
outer waters into Sunday morning. High confidence in near gale gusts
continuing south of Cape Mendocino as Gale conditions develop and
become confined to the northern waters during the day Sunday. Gusts
approaching 40 knots are possible as the strongest winds develop
late Sunday into Monday morning. Steep and hazardous wind waves 9 to
12 feet are forecast in response to these winds, potentially
propagating into the northern inner waters briefly. Conditions will
quickly diminish on Monday as a closed upper low cycles off the CA
coast.


&&

.FIRE WEATHER...Temperatures continue to warm today with high 90s
likely for most of the interior. Overnight recoveries are generally
expected to remain good into mid next week except for a few exposed
ridges where low RH`s may persist through the night. Tonight into
Monday some offshore flow is expected to help keep the marine clouds
and moisture confined to the coast, which may bring some lower
recoveries in northern Humboldt and Del Norte counties. A deeper
marine layer is possible Monday as an upper low approaches the area.
This low also brings a slight chance (10% or higher) for dry
thunderstorms Monday and Wednesday afternoons. Chances remain low as
moisture and instability remain meager, but the position of the low
could change this in either direction still.

The upper level low is forecast to finally eject N-NE by mid next
week as a massive ridge over the four corners region expands over
the area. Much hotter temperatures and drier humidity are highly
probable in the interior late next week. Triple digit temperatures
are likely in most of the interior with very low afternoon RHs and
moderate overnight recoveries.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 5 PM this afternoon to 9 AM PDT
     Monday for PZZ450.

     Small Craft Advisory until 3 PM PDT this afternoon for
     PZZ455-470.

     Gale Warning from 3 PM this afternoon to 3 AM PDT Monday
     for PZZ470.

     Small Craft Advisory until 3 PM PDT Monday for PZZ475.

&&

$$

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