National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS66 KEKA 211209
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
455 AM PDT Sun Apr 21 2024

.SYNOPSIS...Dry weather with above normal temperatures are
expected to continue through Monday. Breezy northerly winds will
developed for coastal areas today as high pressure builds into
the region. Marine stratus is expected to return early Tuesday as
the northerly winds subside. Temperatures will begin a cooling
trend on Tuesday. Moist and unsettled weather conditions return
mid to late next week.


&&

.DISCUSSION...Dry weather with above normal temperatures will
continue today through early next week as weak ridging aloft build
offshore the Pacific Northwest behind a transient shortwave
trough. Areas of valley fog have developed overnight with a strong
radiational cooling. This is expected to clear out during the
morning becoming mostly sunny, despite high cirrus clouds
streaming across the area.

Breezy northerly winds are expected for the coastal areas to
developed this afternoon. Peak wind gust (mostly in the late
afternoon and early evening) of 25 to 35 mph are forecast.
Granted, higher gusts (40-50 mph) are probable (>70% chance) for
wind prone locations; the King Range, coastal headlands of SW
Humboldt and windy point or Pt St George. Winds subside later in
the evening. Meanwhile, offshore flow component is expected to
develop this evening and increase tonight over the exposed ridges,
especially in Del Norte County where gusts from 25 to 35 mph are
likely. This may keep

Interior temperatures are forecast to rebound today, with highs
back to mid 70s to mid 80s. Breezy northerly winds today will
keep the coast in the mid 50s. Monday is forecast to be the
warmest day of the spring season so far as the offshore flow
components strengthen. Warmest interior valleys will likely
(70-90% chance) peak in the mid to upper 80s on Monday. Coastal
temperatures may warm into the mid to upper 60s.

On Tuesday, a 500mb shortwave trough will approach the Pac NW.
Deterministic model guidance continues to indicate increasing
buoyant energy and instability for possible (25-35% chance)
showers and thunderstorms across the interior - mostly Trinity
County - on Tuesday. Also, a closed cyclonic circulation evident
at 925mb will likely induce a southerly wind reversal and a push
of marine air/low clouds from the SW Monday night into Tue
morning. Some cooling is expected on Tue, but high temps will
likely (>60% chance) remain above normal (lower to mid 70s) until
the air mass cools down more drastically toward the end of the
week.

Potential for precipitation will increase mid to late next week
as a colder 500mb trough (temps <-25C). Timing has tightened up to
Thu-Fri with 24 hours probabilities for > 1 inch in 24 hours for
the western slopes of Del Norte and northern Humboldt Counties
around 20 to 30%. There is still a great deal of variability with
timing and precip amounts. Also, there are indications for a
secondary trough in the NW flow on the backside of the main trough
that may spark up more showers Friday night into Saturday (10-20%
chance). It is more certain that interior high temperatures will
cool down by late week - mostly in the 60`s. If snow levels fall
to 5000 feet on Friday, high temps will struggle to reach the
lower 40s in the high mountains Fri-Sat. Precipitation amounts
are forecast to be light, but this time of year even light amounts
will have impacts on outdoor plans or activities. Stay tuned.
ZVS/DB


&&

.AVIATION...Aside from some isolated fog in the Eel river valley,
marginal instability from yertday`s front combined with increasing
north wind along shore have kept any low clouds and fog scoured out.
VFR conditions have prevailed across the area tonight with any
ceilings solidly above 15 kft. Similar VFR conditions will continue
through the day today with north wind gusting up to 30 kts near
coastal terminals being the only notable feature.

Wind will most likely continue to keep the shore scoured out Sunday
night with any coastal fog being very shallow and inconsistent.
Brief IFR conditions would be most likely around Humboldt Bay where
NBM places a 20% chance of brief fog Monday morning.
/JHW


&&

.MARINE...Northerlies have gradually increased throughout the
waters overnight with near gale force gusts observed at near shore
buoys in the wake of a weak cold front. Northerly wind will continue
to strengthen today with increasing coverage of gale force gusts.
The strongest gusts are expected in the far northern waters this
evening with gusts up to 40 kts. The inner water will remain calmer
except for more frequent gales right near Cape Mendocino and Pt. St.
George. Strong wind will support the formation of steep short period
seas in excess of 10 feet through the night tonight.

Building high pressure over the interior will help shunt strong
winds further offshore Monday through midweek, brining calmer
conditions at least to the near shore waters. Short period wind
waves will dominate the sea state except for a series of minor mid
period northwest swells up to 5 feet persisting through the week.
/JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PDT Monday for PZZ450.

     Small Craft Advisory until 9 PM PDT this evening for PZZ455.

     Small Craft Advisory until 3 PM PDT this afternoon for
     PZZ470.

     Gale Warning from 3 PM this afternoon to 3 AM PDT Monday
     for PZZ470.

     Small Craft Advisory until 3 AM PDT early this morning for
     PZZ475.

     Gale Warning until 9 PM PDT this evening for PZZ475.

&&

$$

Visit us at https://www.weather.gov/eureka

Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka

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