Philo, California Weather Forecast Discussion

471
FXUS66 KEKA 102044
AFDEKA
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
144 PM PDT Wed Sep 10 2025
.SYNOPSIS...Showers and thunderstorms are expected to taper off
this evening and overnight. Thursday a few showers and
thunderstorms are possible over the mountains. Friday and Saturday
are expected to remain dry with more rain possible Sunday and
Monday with dry weather returning after that.
&&
.DISCUSSION...The large upper level continues to spin over
northern CA/Southern Oregon. In the mid level water vapor you can
see several small circulations rotating in the parent low. These
small circulations are moving over the area and helping to
enhance the showers and thunderstorms developing across the
interior this afternoon. The models are showing 300 to 500 j/kg of
CAPE and PWATS are around 1.1 inches. Some of these may produce
locally heavy rainfall. At this point it looks like any showers
that make it out to the coast will be fairly small and weak.
Tonight any areas that do clear out will likely see widespread
low clouds and fog. Thursday afternoon there is slight chance for
showers and thunderstorms once again, but these are expected to
be limited to eastern Trinity and eastern Mendocino and Lake
counties. Confidence is a lot lower and coverage is expected to
be a lot less tomorrow. Mid level lapse rates are not very steep
and instability is quite a bit lower than today.
Thursday night into Friday morning there is expected to be quite a
bit of fog around and good RH recoveries. This will likely take
some time to clear out, but eventually sunny skies and warmer
temperatures are expected in the afternoon. Low clouds and fog are
expected to diminish in coverage Friday night into Saturday
morning. Dry weather is expected for much of the day Saturday and
temperatures are expected to warm over Friday. There is the
potential for another upper level low to bring some rain to the
area. The NBM POPS show it potentially arriving as early as
Saturday afternoon, but the deterministic models are slower and
show it more likely on Sunday. Current model runs are showing
fairly light precip and there is the potential for some lightning
as well. Once this moves past the area on Monday or Tuesday dry
weather is expected to return. MKK
&&
.AVIATION...(18Z TAFs)...IFR to LIFR conditions along the coastal
terminals due to stratus and degraded visibilities. LAMP
probabilities shows high confidence (>75%) in the continuation of
MVFR ceilings below 3kft AGL and only a 30% probability of ceilings
staying below 1kft AGL (30%) midday through the early evening (21Z-
03Z. Light variable winds are expected this morning before turning
into light northerly breezes, potentially increasing daytime mixing/
periodic scattering at terminal sites. Offshore winds aloft in Del
Norte Co. could potentially lead to overnight clearing as well, more
updates expected as forecast confidence improves.
KUKI is observing low, MVFR ceilings. For KUKI and other inland
terminals, HREF model data is confident in the continuation of
clouds around inland terminals today as convection is forecasted
near the Yolla Bollys as well as in Mendocino and Lake Counties.
Gusty outflows/inflow winds are possible, as is locally moderate to
heavy rain. Turbulence is possible near all terminals due to micro-
scale updraft winds. In areas without convection, afternoon breezes
are expected.
&&
.MARINE...As an area of low pressure moves towards the east,
northerly winds are forecast to increase and remain through the end
of the week. Sustained winds peak at around 20-25 kts in the outer
waters in the afternoons each day with gales of 25-30kts possible.
Wind waves of 6-7ft expected with these strong breezes. Small craft
advisories in effect through the weekend due to the steep wind waves.
Besides wind waves, both a northwesterly swell, and a southerly
swell are being observed today, yet they remain relatively small,
around 2ft.
A long period, NW swell of 5-6 is forecast to fill in Friday
morning. Combined seas may reach 7-9 ft by Friday with the
combination of the swell and the wind waves. Sea conditions are
expected to ease slightly Saturday afternoon through Sunday as
another weather system enters the area easing marine winds. Combined
seas are expected to rise as a larger mid-period NW swell fills in
Sunday evening/Monday early morning.
&&
.FIRE WEATHER...Numerous wet thunderstorms are moving through the
area this afternoon. These are expected to diminish tonight. Winds
will generally remain light overnight. Additional thunder storms
are possible on Thursday. Any storms that do form are expected to
be drier. PWATS are lower and the bases are higher. Friday morning
there is expected to be some offshore flow in Del Norte county,
but RH is expected to remain high so this isn`t expected to be an
issue. Saturday morning RH recoveries are expected to be lower,
but winds will also be lighter. Saturday night or Sunday another
weather system is expected to move into the area, but confidence
is low on the impacts at this point. MKK
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 3 PM this afternoon to 3 PM PDT
     Thursday 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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NWS EKA Office Area Forecast Discussion