####018005673####
FXUS66 KEKA 152146

AFDEKA



AREA FORECAST DISCUSSION

National Weather Service Eureka CA

246 PM PDT Thu May 15 2025



.SYNOPSIS....A couple weak systems to periodically increase 

cloud cover and present low chances for a few showers or light 

drizzle through Saturday. Breezy northwest winds are anticipated 

through the afternoons, with increasing strength Saturday and 

especially Sunday. Above normal temperatures are expected next

week. 



&&



.DISCUSSION...Another weak weather system riding down the east

side of the ridge is expected to bring some clouds and possible

some light showers in Del Norte county. Temperatures have warmed

into the mid 70s to low 80s this afternoon in the inland areas

while the coast lingers in the upper 50s. Breezy winds continue

this afternoon along the coast with gusts around 25 mph. Stratus

is expected to spread up the river valleys again tonight. Friday

conditions will be fairly similar to today, although possibly a

few degrees cooler. Winds will also be lighter in the afternoon. 



Friday night into Saturday a slightly stronger weather system 

moves into the area bringing cooler temperatures and the potential

for some rain or drizzle. For the Del Norte county inland areas 

the NBM is show a 20 to 30 percent chance of a tenth of an inch of

rain. Northern Humboldt and Northern Trinity are only showing a 5

to 15 percent chance of a tenth of an inch with less than a 5 

percent chance farther south. Winds are expected to increase 

Saturday afternoon behind this system with gusts to 35 mph along 

the coast and up to 40 mph in the southern inland areas. High 

temperatures will also be cooler for the inland areas with highs 

only around 70 in the warmer valleys and upper 50s along the 

coast. Sunday inland temperatures are expected to start warming 

but only a few degrees over Saturday. Saturday night is expected 

to be the coolest nights with some of the colder valleys 

potentially seeing frost if they can remain clear. 



Next week high pressure is expected to build back into the area

and the inland areas could see highs over 90 degrees. Currently

the NBM is showing a 30 to 50 percent probability of the inland

valleys exceeding 90 degrees. The models are generally showing

high pressure, but there are some indications that some weak

shortwaves might move over the top of the ridge bringing cooler

temperatures. MKK



&&



.AVIATION...Steady northerly winds blocked by the coastal terrain 

will result in low cloud redevelopment this evening and overnight 

over Humboldt Bay and Eel delta. MVFR ceilings are highly probable 

for KACV with lower chances for IFR ceilings by daybreak Friday. 

Sporadic MVFR or IFR cigs will also be possible at KCEC once 

northerlies subside and small scale eddies generate light southerly 

and southeasterly winds nearshore. Otherwise for UKI, VFR with 

occasional mid/high is expected. Now winds will remain gusty for 

coastal terminals early this evening with peak gusts to 25 kt or so. 

There is a 50% chance for turbulence and low level wind shear for 

small aircraft, particularly around KACV once surface gustiness 

decouples this evening. Chance for turbulent flow and shallow 

mountain waves will continue tonight over southern Humboldt county 

interior (King Range) and much of western Mendocino county. DB 



&&



.MARINE...Surface ridging extending from a high centered over the 

northeast Pacific coupled with a thermally induced trough over the 

California interior will continue to produce northerlies with to 25 

to 30kt over the waters through tonight. Winds will ease to 10 kt or 

less nearshore by late evening, however. High resolution models 

continue to depict a couple of expansion fans in the lee of Cape 

Mendo and Cape Blanco this afternoon and evening. Strongest 

expansion fan is forecast to occur south of Cape Mendocino where 

gusts to 35-40 kt are highly probable based on HREF. Gale warning 

remains marginal with coverage of gusts > 35kt less than 50% for 

marine zones 475 and 455. 



Pressure gradients will start to relax north of Cape Mendo on Friday 

as a weak front approaches from the NW. Winds and seas are forecast 

to subside in response north of Cape Mendo. South of Cape Mendo, 

gradients will remain sufficiently tight to support gusts to 25-30 

kt for a continuation of advisory conditions. Waves will also remain 

sufficiently steep and uncomfortable south of Cape Mendo; around 6 

to 8 ft at 7 seconds. 



Northerly winds and steep waves will increase again over the weekend 

with small craft advisory conditions likely both north and south of 

Cape Mendo by Sat afternoon and evening. Pressure gradients may 

become sufficiently steep to support gusts over 35 kt in the lee of 

Cape Mendo by Sunday. DB 



&&



.EKA WATCHES/WARNINGS/ADVISORIES...

CA...

None.

NORTHWEST CALIFORNIA COASTAL WATERS...

     Small Craft Advisory until 9 PM PDT this evening for PZZ450.



     Small Craft Advisory until 3 PM PDT Friday for PZZ455.



     Small Craft Advisory until 3 AM PDT Friday for PZZ470.



     Small Craft Advisory until 3 PM PDT this afternoon for 

     PZZ475.



     Gale Warning until 9 PM PDT this evening for PZZ475.



&&



$$



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For forecast zone information

see the forecast zone map online:

https://www.weather.gov/images/eka/zonemap.png