Whitethorn, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

678
FXUS66 KEKA 100705
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1205 AM PDT Tue Jun 10 2025

.SYNOPSIS...Isolated thunderstorm threat for Trinity, Del
Norte, and NE Mendocino County continues Tuesday afternoon into the
evening. Warm temperatures continue Tuesday, however, a cooling
trend will keep temperatures cooling steadily through the week into
the weekend.

&&

.DISCUSSION...* Isolated afternoon and early thunderstorms in the interior,
  primarily Trinity County on Tuesday. Cloud-to-ground lightning
  strikes and gusty erratic winds possible.

* Interior heat risk diminishing and becoming low on Wednesday.
  High temperatures generally decreasing each day this week along
  with cooler overnight low temperatures late this week.

* Gustier afternoon and evening westerly and northwesterly breezes
  expected mid to late week.


An upper level ridge over California will migrate eastward as a weak
upper level trough swings over our area from the north. This
synoptic weather change will ad variety to our daily weather. First
and foremost, there is CAPE aloft over the Klamath mountains,
allowing for daytime heating to pop into thunderstorms for one more
afternoon. The GFS is showing "Most Unstable CAPE" values centered
over Del Norte, Trinity, and Northeastern Mendocino County Tuesday
night. Brief wetting rain, cloud to ground lighting, and small (pea-
sized) hail is possible with these storms. upper level vorticity
will be present in the 700mb level which could help sustain some
thunderstorm briefly. However, the storms look relatively dry with
the troposphere being at 46% RH by 00Z/5PM.

Tuesday has a decreased chance in the NBM probability for thunder
with the Trinity Horn area having a 10-20% chance of thunderstorms.
Del Norte and NE Mendocino show only a 0-5% chance so confidence
remains low for storms developing in those areas. THe majority of
the convective development looks to stay much further east of CWA in
southern OR and NE CA. Potential for gusty winds and dry lightning
could be a fire weather concern for these areas. This incoming
trough looks quite dry and main impacts appear to be a return of
stronger gusty winds and cooler temperatures.

Inland valleys will struggle to break 90F on Wednesday through the
rest of the week and weekend. High tempertures look to be around the
low 80s at the warmest for inland valleys Friday and Saturday as of
right now. This comes a relief after what has been a warm couple of
weeks to start meteorological summer. These cooler temperatures will
also be accompanied by stronger winds with afternoon wind gusts
around 15-20mph in the later portion of the week.


&&

.AVIATION...A strong marine inversion has persisted along the coast
and has gradually lowered to LIFR ceilings overnight. Ceilings will
most likely continue to drop through the night with short periods of
dense fog (50% chance) likely along the coast around sunrise. High
resolution models indicate ceilings will be slow to lift along the
coast with Humboldt Bay even having a 30% chance of at least IFR
conditions persisting all day. The interior, meanwhile, will remain
VFR with isolate afternoon thunderstorms over high terrain being
the greatest potential concern. /JHW


&&

.MARINE...Gentle northerly winds have continued to spread throughout
the waters overnight with short period seas generally below 5 feet.
North winds will steadily increase in the outer waters through
around midweek with strong wind gusts in the southern outer waters
by Wednesday morning. Strong winds will spread north by Thursday
with near gale force gusts fanning south of Cape Mendocino. The sea
state will be nearly entirely controlled by short period wind waves
of 5 to 7 feet around mid week. High pressure stalling over the
eastern Pacific will encourage strong northerly winds to continue
into the weekend. /JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 9 PM this evening to 9 PM PDT
     Wednesday 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