376
FXUS66 KEKA 302118
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
218 PM PDT Sat Aug 30 2025

.SYNOPSIS...Near seasonal average temperatures will continue
through the weekend. A warming trend will increase the HeatRisk
and fire weather threat as low RH and hot temperatures build across
the interior on Monday and then peak on Tuesday. The coast is
expected to see night and morning clouds with some afternoon
clearing most days. There is a slight chance of thunderstorms on
Tuesday in the interior.


&&

.DISCUSSION...The skies are plenty of sunshine across Northwest
California this afternoon. Afternoon temperatures are running 2
to 5 degrees cooler across the northern portion of the forecast
area compared with yesterday`s reading, while few degrees warmer
across interior Mendocino and Lake counties. Breezy west to
northwest winds are expected to developed through the channeled
terrain, while breezy north winds over the coastal headlands.


Southwesterly winds aloft will continue to push the smoke from the
active wildfires in Siskiyou and Trinity counties toward northeast
out of the area through the weekend. The exception will be areas
north of the Peak Fire between Trinity Lake and Granite Peak.
There will likely be local terrain effects that will continue to
bring smoke to the valleys in all directions near the fires. This
will be especially true if the fire is burning below the inversion
and the smoke is trapped. For details visit weather.gov/eka and
check out the area smoke forecast on the bottom of the main page.

For the Labor Day (Monday), the high pressure begin to builds
north into the area through Tuesday. Interior heat will build on
Monday and then peak on Tuesday. High temperatures in the hottest
valleys are expected to range from 95 to 105F degrees. Expect
widespread Moderate HeatRisk across the interior. The heat will
have impacts on some individuals sensitive to heat, especially
those without effective cooling and/or adequate hydration. Coastal
areas are expected to remain generally in the mid 60`s to low
70`s.

A southerly reversal shortwave trough moving up the west side of
the ridge Tuesday through Thursday. This is expected to draw some
moisture up and bring the potential for thunderstorms over the
interior. The challenge is in the details of the timing, location and
how much moisture is available. The GFS has expanded the threat of
thunderstorm across much the Trinity County and surrounding areas
for late afternoon and evening on Tuesday, while the ECMWF limited
the threat over the Sacramento Valley. Have to expanded the slight
chance of thunderstorms in Trinity County for Tuesday. Coverage
may be increase toward eastern Humboldt and eastern Del Norte with
enough energy aloft and increasing PWAT values toward the coast,
but will wait for more model runs to increase confidence.

Wednesday through late in the week, the shortwave trough will
continue to move northward with dry weather prevailing across the
area. Clusters and operational deterministic models are trending
dry for Wednesday, with drier air-mass moving over the area.
Ensemble clusters are in pretty good agreement showing this
pattern with around 70 percent of the members./ZVS


&&

.AVIATION...Apart from brief LIFR impacts early this
morning, all terminals remained VFR overnight. Remaining stratus has
mostly moved offshore and scattered out late this morning. A trough
moving through the Pacific northwest continues to support a weak
marine inversion, but there are some hints of a shallow marine layer
returning overnight. Offshore flow may complicate visibility
impacts, but LIFR or IFR ceilings are likely if stratus does
develop. UKI remains VFR today with breezy winds in the afternoon
easing overnight. Smoke impacts are mostly limited to Siskiyou and
northern Trinity Counties. JB


&&

.MARINE...Northerly winds continue to increase in the lee of Cape
Mendocino, with gusts up to 25-30 kts forecast near the Cape. Winds
are lighter elsewhere, with gusts peaking at 5-15 kts this
afternoon. Seas also remain mild, with combined seas of 1-2 ft
observed on buoys. A small long-period southerly swell is filling in
this morning and will persist trough the weekend. Higher seas of 4-5
ft are found south of Cape Mendocino, and these will slowly build as
northerlies gradually increase. Stronger winds may reach nearshore
Mendocino Sunday afternoon, with gusts peaking around 20-25 kts. By
Sunday night into Monday, winds increase in the northern outer
waters to 20-25 kts, but nearshore areas are likely to continue to
see lighter winds. This general pattern continues into mid next
week. JB


&&

.FIRE WEATHER...Elevated fire weather conditions due to low RH
and breezy westerly winds over the higher terrain in zones 277,
283 & 264 continue this weekend. Dry weather will continue through
early next week, with low daytime RH mainly in the teens and poor
to moderate overnight humidity recoveries in areas well away from
the coast. Winds will generally be diurnally and terrain driven.
However, a period of enhance afternoon winds with gusts to 25 mph
is expected. A headline for elevated fire weather threat continue
in the Fire Weather Forecast. Next week a warming and drying
trend is expected with high temperatures forecasted to peak in the
upper 90s to near 105 across the interior valleys on Tuesday.
There is also a slight chance of afternoon and evening
thunderstorms on Tuesday, mainly in Trinity county.



&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 11 AM to 11 PM PDT Sunday for
     PZZ455.

     Small Craft Advisory from 5 AM Sunday to 11 PM PDT Monday
     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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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png