Glenhaven, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

818
FXUS66 KEKA 300706
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1206 AM PDT Fri May 30 2025

.SYNOPSIS...Hot conditions will peak Friday and Saturday with gusty
winds along the coast by Sunday afternoon. Generally warm and dry
conditions will continue through the start of June.

KEY MESSAGES:

-Hot conditions with triple digit temperatures across the interior.
Moderate HeatRisk today and Saturday.

-Strong gusty winds along the coast Sunday and Monday afternoon.

-Low (10%) chance of isolated dry thunderstorms over high terrain
 on Sunday.


&&

.DISCUSSION...A strong but narrow ridge of high pressure
is currently building over the area, bringing clear skies and hot
weather to the interior, along with shallow marine influence and
nighttime fog along the coast. Heat will most likely peak today with
high temperatures most likely to crest over 100 degrees for the
first time this year, especially around Ukiah, Clearlake and along
the Trinity River Valley. The confidence in temperatures of 100 or
higher is high (90 percent) but the overall risk drops to around 30%
for any highs over 105. Given the short nature of the event, the
overall HeatRisk is moderate. Marine influence and a strong sea
breeze will keep the immediate coast much cooler with marine air
extending as high as around 1000 feet in elevation.

High pressure will gradually eject south and east with a robust mid
level trough stalling over the eastern Pacific by Sunday. This will
setup a very strong pressure gradient along shore just over the
coastal waters, which will generate very strong north winds
throughout the waters but also in exposed areas along the coast.
Exposed ridges like in the King Range could see gusts as high as 50
mph. Stable marine air is likely to subdue winds slightly, but gusts
around 40 mph are most likely at low elevations. There remains some
potential (40%) for marginal wind advisory conditions along the
coast with gusts over 45 mph at low elevations. The risk is greatest
(70%) on headlands around Crescent City.

As the trough moves onshore Sunday, some mid to upper level moisture
will be advected northward to our area. Models are hinting for a
small chance for thunderstorms, but probabilities remain below 10%.
Some model soundings do show some instability, but also a weak cap
which currently keeps thunder probabilities low. High-resolution
models will provide more insight as they get into range. The trough
will move inland early next week. Long range ensembles show
generally high confidence in warm, dry conditions continuing through
the first week of June. JHW/JB


&&

.AVIATION...LIFR ceilings with a 50% to 70% chance of 1/2SM in fog
expected early this morning at coastal forecast terminals (ACV and
CEC). Conditions are forecast to improve through the day on Friday,
though a shallow and compressed marine layer may linger along the
shoreline and result in LIFR cigs and perhaps fog at KACV and KCEC
into the afternoon hours. Otherwise, VFR is expected for much of the
interior except for early morning low clouds and fog in North Coast
river valleys and Eel delta. DB

&&

.MARINE...Northerly winds and steep waves will continue to increase
on Friday with small advisory conditions (15-25 kt with gusts to
30kt) primarily in the outer waters and nearshore downwind of Cape
Mendocino through Saturday morning. A 1038mb high pressure center
offshore over the NE Pacific will build this weekend and interact
with a deep low pressure system over the California interior.
A very tight pressure gradient between the high and the low is
forecast to develop over the waters, resulting in a full gale and 18
to 25 foot seas by Sunday afternoon and evening. Storm force gusts
up to 55 kt are possible, about a 50% chance Sunday afternoon and
evening. Guidance continues to indicate high probabilities (>60%)
for gales continuing into early next week (Mon and Tue), especially
across the outer waters. Seas will most likely remain quite
elevated, around 15-20 feet. DB


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Heat Advisory from 11 AM to 9 PM PDT Friday for CAZ105-106-
     110-113.

     Heat Advisory from 11 AM Friday to 10 PM PDT Saturday for
     CAZ107-108-111-114-115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Gale Watch from Saturday evening through Sunday evening for
     PZZ450-470.

     Gale Watch from Saturday afternoon through Sunday evening
     for PZZ455-475.

     Small Craft Advisory until 7 PM PDT Saturday for PZZ470.

     Small Craft Advisory until 1 PM PDT Saturday 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