Douglas City, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

778
FXUS66 KEKA 161857
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1157 AM PDT Mon Jun 16 2025

.SYNOPSIS...Increasing afternoon breezes and some fire weather
concerns in southern Mendocino and Lake County early this week.
Warmer temperatures and minor HeatRisk concerns mid week. Much
cooler temperatures and chances for light rain Friday and through
the weekend.


&&

.DISCUSSION...In the near term, an approaching shortwave trough
is bringing some weak elevated instability and moisture this
afternoon. Moisture and instability is lacking, but a low chance
(up to 5%) exits for far NE Trinity County. There are some weak
radar returns over the ocean well offshore and over the interior.

Weak ridging will begin building in behind the trough. Inland valley
temperatures will warm into the low to mid 90s, with some upper 90
in Lake County on Wednesday. This will present minor HeatRisk
concerns. Temperatures will trend lower next Thursday with
another weak shortwave trough passing. Initial analysis of this
trough does not show much chances for convective impacts, but
features as this always bear watching this time of year.

A seasonally anomalously strong trough is then forecast to dive
south into the region next Friday. NBM currently holds up to a 54%
chance for over 0.1 inches of rain Friday through Saturday. Some
ensemble members show chances for higher amounts. There is the
potential some of this precipitation may be in the form of
thunderstorms with steep lapse rates and elevated instability. One
of the more "extreme" scenarios (20% chance) is over a half inch
of rain in Del Norte and perhaps a few snowflakes over the highest
peaks. Chillier low temperatures are possible behind the system
as well, with lows in the 30s likely in most of Trinity and the
coldest valleys of Mendocino and Humboldt. Cluster analysis shows
strong agreement in this scenario. JJW


&&

.AVIATION...(18Z TAFs) Coastal MVFR conditions are expected to give
way to VFR categories during the daytime. FEW-SCT ceilings could
remain through the day at KACV before a possible return of stratus.
As an upper level ridge enters the area, the marine layer is
expected to be thinner, possibly giving IFR-LIFR conditions tonight
along the coast and adjacent coastal river valleys. Inland can
expect moderately gusty afternoon winds and VFR conditions.
Scattered high level clouds are also expected through the day as
the remnants of a front passes overhead.

Confidence: HREF data shows about a 50% chance for low cloud
coverage tonight. In addition, there is only around a 20-30% of
those cloud ceilings being below 1000ft AGL. However, some individual
model soundings show the cloud coverage reaching potential LIFR
conditions due to low clouds. TEMPO groups have been added to give
an idea on forecast confidence with regards to timing for coastal
stratus.


&&

.MARINE...Winds are forecasts to ease from the northern outer
waters through the day, as small craft advisories now cover inner
and outer waters south of Cape Mendocino (PZZ475 & PZZ455). The sea
state will be largely dominated by steep short period wind waves
today before calming with the easing winds. As the winds and wind
waves die down, a small mid-period NW swell enters the area waters
early Tuesday morning. These calmer conditions will be short lived
however, as fresh breezes return to the southern waters Wednesday
through the rest of the week. Depending on the wind wave responses
to these winds, small craft advisory well could be issued for
Wednesday in the southern waters. Later in the week and into the
weekend, a late season cold front passing over the PacNW will cause
the land-sea temperature difference that creates the pressure
gradient which drives our coastal winds to weaken, bringing gentle-
to-moderate breezes and a mid-period small NW swell to the
coastal waters.


&&

.FIRE WEATHER...A shortwave trough is passing through this
afternoon. There are some light shower returns showing up early
this afternoon, but surface precipitation is not expected. There
is very limited moisture aloft and a very small chance (less than
5%) for an isolated dry thunderstorm over NE Trinity this
afternoon.

Northerly winds are increasing in southern Mendocino and Lake County
this afternoon again, strongest in southern Mendocino and Lake
counties. These will trend slightly lower Tuesday, but will remain
gusty in the afternoons. Minimum RH values will trend lower early to
mid next week, with some values in the mid to upper teens Wednesday.
Locally elevated to some brief critical fire weather conditions will
develop with these afternoon wind pulses and lowering RH. A cold
upper low will dive south into the region late this week and into
the weekend. Northerly winds will increase again with this trough,
but RH will trend higher and temperatures will likely turn
anomalously cooler through next weekend. JJW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 10 PM PDT this evening for
     PZZ455-475.

&&

$$

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