Frost Advisory 17, NWS Eureka, CA

984 
WWUS76 KEKA 051436
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
736 AM PDT Mon May 5 2025

CAZ106-051700-
/O.CON.KEKA.FR.Y.0017.000000T0000Z-250505T1700Z/
Southern Humboldt Interior-
Including Dinsmore
736 AM PDT Mon May 5 2025

...FROST ADVISORY REMAINS IN EFFECT UNTIL 10 AM PDT THIS MORNING...

* WHAT...Temperatures as low as 37 will result in frost formation.

* WHERE...Southern Humboldt Interior, mainly in eastern Humboldt 
  county in Larabee Valley and other higher elevation valleys.

* WHEN...Until 10 AM PDT this morning.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive 
  outdoor plants may be killed if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

CAZ108-051700-
/O.CON.KEKA.FR.Y.0017.000000T0000Z-250505T1700Z/
Southern Trinity-
Including Hayfork
736 AM PDT Mon May 5 2025

...FROST ADVISORY REMAINS IN EFFECT UNTIL 10 AM PDT THIS MORNING...

* WHAT...Temperatures as low as 32 will result in frost formation.

* WHERE...Southern Trinity county, especially the Hayfork Valley. 

* WHEN...Until 10 AM PDT this morning.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive 
  outdoor plants may be killed if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

CAZ115-052100-
/O.CON.KEKA.WI.Y.0017.000000T0000Z-250505T2100Z/
Southern Lake-
736 AM PDT Mon May 5 2025

...WIND ADVISORY REMAINS IN EFFECT UNTIL 2 PM PDT THIS AFTERNOON...

* WHAT...North winds 25 to 35 mph with gusts up to 55 mph.

* WHERE...Southern Lake county over the higher terrain and exposed 
  areas.

* WHEN...Until 2 PM PDT this afternoon.

* IMPACTS...Wind gusts will be particularly strong over the exposed 
  ridges. There is an increased risk of tree branches and other 
  debris on roadways. Gusty winds will blow around unsecured 
  objects. Tree limbs could be blown down and a few power outages 
  may result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution.

&&

$$

For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka

EYS

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Eureka CA
232 PM PDT Sun May 4 2025

.SYNOPSIS...Strong and gusty northerlies continues today in coastal
areas and over exposed ridges. Robust offshore flow and warming
expected tonight and Monday. Offshore flow weakens on Tuesday. Dry
weather with above normal interior warmth expected all next week.

&&

.DISCUSSION...Northerly winds have picked up quite a bit this
afternoon and will continue into the evening hours. Peak gusts
around 40mph have been observed at the county line ridge in
eastern Lake county, bordering Colusa. Winds ease in magnitude
overnight, yet some areas will still remain gusty, particularly in
far eastern Lake and southeastern Trinity bordering Tehama county.
Wind fetch will recede away from near shore areas by the late
morning/early afternoon on Monday. Temperatures overnight into
Monday could mimic this mornings' lows with frost in the decoupled
valleys. Frost and freezing temperatures will be possible again
for the interior valleys in Trinity early Monday morning. Airmass
warms tonight, but skies will be clearer, winds light and
dewpoints lower.

Main impacts today through Monday continue to be strong and gusty
northerly to northwesterly winds. NBM means continue to indicate
peak gusts generally around 25-35 mph. Windier points,
particularly wind-prone headlands around Pt St George, Cape
Mendocino and Pt Arena will probably gusts to 40-50 mph this
afternoon and early evening. These strong winds will have impacts
on recreation and other outdoor activities today.

A 925mb northerly speed max (35-45kt) will form over the central
valley this afternoon and evening, and expand into a swath of NE
winds by early Monday. Robust NE winds are expected over the higher
elevations, especially over eastern Mendocino and eastern Lake
Counties. NBM means continue to indicate NE wind gusts in the lower
elevations around 20-35 mph. Gusts to 45 mph or more are possible in
the lower elevations with HREF and NBM probabilities around 40% for
Cobb and 10-30% elsewhere. Windy conditions are expected to continue
on Monday, but will most likely diminish for coastal areas as the
airmass warms and stability increases.

High temperatures in the interior will warm above seasonal averages
on Monday and remain above average on Tuesday. Highs may reach or
exceed 90F at Ukiah, Willow Creek and Hoopa (65% chance) by Tuesday
as a thermal trough develops and 850mb temps increase to 15-17C.
Robust offshore flow will keep coastal stratus limited in coverage
and duration or non-existent Monday and Tuesday.

Upper ridge axis over the PAC NW is forecast to shift southeastward
around mid week. Precip chances remain low (<5%) as a trough over
the Gulf of Alaska edges south and eastward. Nearshore southerlies
may result in stratus by mid week. A decaying front may bring a
shallow push of moist air and an outside chance (<10%) for coastal
drizzle. Interior high temps are forecast to remain above normal for
the rest of the week. Most ensemble clusters indicate above normal
500mb heights and above normal interior warmth into Saturday.
40% indicate faster and deeper trough progression on Saturday, so
precip chances and thunder will be possible as early as Sunday (May
11). DB /EYS

&&

.AVIATION...Remaining clouds have cleared out as a
drier airmass builds in and mixing commences from upper level
winds down to the boundary layer. Gusty northerly winds are
forecast at all terminals and are likely to peak in the afternoon.
Stronger easterly winds at around 2000 ft AGL are bringing a LLWS
threat to KCEC, KUKI, and KACV through the evening. Winds aloft
with a northerly bearing will help diminish the LLWS threat. This
will be shortlived as gusts return this evening. VFR conditions
are expected to continue overnight. JB /EYS

&&

.MARINE...In the wake of yesterday morning's cold frontal passage,
inland temperatures have increased today causing a surface pressure
gradient forcing strong, gusty, gale force winds over the coastal
waters. NBDC Buoy data is showing gale force winds with gusts up to
35kts in the inner coastal waters with the latest ASCAT polar
satellite scatterometer scan showing elevated sustained winds in the
outer waters as well. Winds will continue to increase through the
afternoon. These winds are a producing chaotic and hazardous sea
state due to large, steep wind waves. Waves will be largest in the
southern waters through Monday evening, when the winds begin to die
down to near gale conditions.

An upper level trough will move away from our area towards inland
western CONUS allowing ridging to fill over the Pac NW this week.
The ridging will allow a thermal trough pattern at the surface
keeping winds elevated, yet below gale force, through the week. Wind
waves will create a sea state that can be hazardous for small
crafts through midweek.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Gale Warning until 9 PM PDT this evening for PZZ450-455.

     Hazardous Seas Warning from 9 PM this evening to 9 AM PDT
     Monday for PZZ450-455.

     Gale Warning until 3 AM PDT Tuesday for PZZ470-475.

&&

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png