Philo, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

493
FXUS66 KEKA 242232
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
332 PM PDT Sun May 24 2026

.SYNOPSIS...Stratus remains over the coastal areas as eddies
offshore recirculate flow back to the shoreline. An upper level low
approaches the area Monday, bringing light rain and cooler
temperatures with gusty winds. Chances for thunderstorms increase
Tuesday and Wednesday.


&&

.KEY MESSAGES...

- Cooler temperatures and higher mixing ratios as moisture and
  colder air mass approaches with the low pressure system.

- Pop up cumulus already in effect today in northern Trinity.
 CAPE up to 1000 j/kg near Weaverville area and south to the Yolly
 Bollys.

- An approaching upper level low will bring gusty winds and light
  precipitation to Del Norte and northern Humboldt Monday.

- CAPE is modest for Tuesday in Trinity and Wednesday in Lake
  county but could produce thunderstorms on the backside of the
  exiting low.


.DISCUSSION...Returning stratus is persistent thanks to the coastal
eddies recirculating surface flow back into the lower elevation
coastal areas. Stratus is persistent near Humboldt bay and as far
inland as a few miles east of Blue Lake. This evening into Monday
early morning will fill in as the next low pressure system
approaches.

A few convective cells have popped up over Trinity, and the Yolla
Bolly district. NBM shows CAPE values in the 900-1000 j/kg near
Weaverville and up the Trinity horn this evening. It is more
likely that there will be a few showers and lightning in isolated
areas of Trinity county which will lose energy by 03-04z. The past
few days we have had cells producing showers and lightning but
they have waned by 01-02z, mostly in Trinity. The approaching low
has a 70-80% probability of producing rain accumulation >
0.03inches in Del Norte Monday and around a 35-45% chance for >
0.03inches in northern Humboldt, also on Monday. The back side of
the approaching low will prime the atmosphere for more convective
activity. Trinity county looks to have modest CAPE Tuesday and
Lake County has gusty winds and low CAPE values Wednesday
afternoon. The timing on Wednesday with the gusty winds and CAPE
could produce some thunderstorms. Confidence is low to moderate.
See the Fire Weather discussion below. /EYS


&&

.AVIATION...(18Z TAFs)...IFR to MVFR conditions are likely to
continue for the coastal areas through the evening. Interior areas
are likely to clear this afternoon with VFR conditions expected.
This evening and overnight, stratus will build back in for the
coastal areas with LIFR to IFR ceilings expected. IFR to MVFR
stratus is possible again for UKI tonight as south winds and a deep
marine layer return cloud cover. JB


&&

.MARINE...Winds and seas have eased with generally light southerly
winds expected today and Monday. Seas are dominated by decaying
northerly winds waves and a long period NW swell at around 3 to 5
ft. A weak cold front arrives Monday evening and winds and seas are
expected to rapidly increase as strong NW winds fill in behind the
front. Expect these to build substantially through the week,
especially for the southern outer waters where there is an 80-100%
probability of gale force winds developing by Tuesday. A mid period
NW swell arrives Tuesday, peaking at around 12 ft. This swell along
with building steep northerly wind waves could bring significant
wave heights over 15 ft by Wednesday. Winds are likely to remain
strong for much of the next week. JB


&&

.FIRE WEATHER...Late afternoon convection in Trinity county and the
Yolla Bollys are expected again today as atmospheric dynamics
prime the conditions for convection. Colder air approaches with
the low pressure system, expected to arrive Monday. Not enough
CAPE for activation Monday but values increase Tuesday for Trinity
County and Wednesday for Lake. Sustained winds around 24mph with
gusts up to 35mph late Tuesday evening pick up again Wednesday
afternoon for both Trinity and Lake. Modest CAPE Wednesday has
good timing with the gusty winds in Lake county for zones 418 and
421. RH values will be around 25% at their lowest with wet
convective cells rather than dry which lowers the risk of fire
spreading if starts happen from lightning with fuels not being
quite cured. /EYS


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 9 PM Monday to 3 AM PDT Wednesday
     for PZZ450-455-470-475.

&&

$$

NOTE: The full forecast discussion is now regularly issued between
10 am/pm and 1 pm/am. Additional updates will be issued as needed.

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