Witter Springs, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

952
FXUS66 KEKA 060850
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
150 AM PDT Mon Apr 6 2026

.SYNOPSIS...Above normal warmth is forecast to continue through
today in the interior and then trend cooler later in the week.
Chance for showers and interior thunderstorms will arrive on
Wednesday and continue on Thursday and Friday.


&&

.KEY MESSAGES...

* Interior highs in the mid 70s into low 80s today with minor
  HeatRisk.

* Light showers on Wednesday, followed by showers and interior
  thunderstorm chance Thursday and Friday.

* Shower activity will persist across the region through at least
  Saturday due to lingering moisture rotating around the cut-off
  low tracking southeastward into Southern California.


&&

.DISCUSSION... A weak shortwave trough embedded in southwesterly
flow aloft is passing overhead the NW California overnight, with
high level clouds streaming the area. In addition, a shallow
marine layer have developed with stratus and patchy fog blanketed
much of the coastal waters and adjacent land areas. Patchy dense
fog is already observed around Humboldt Bay with visibility of 1/4
or less. HREF probability for dense fog continue suggesting there
is a 30-50% chance of dense fog along the Hwy 101 between Eureka
and Crescent City from 5 AM to 9 AM this morning. Fog and patchy
dense fog is expected along the river valleys and adjacent coastal
areas early this morning. The shallow marine layer and stratus
should erode back and clear out in the afternoon, but areas of fog
and low cloud may linger near or meander about near the shoreline
through the day as winds remain light and variable.

Otherwise, quiet and dry weather and above normal high temperatures
are forecast to prevail across the interior through at least
Tuesday as a ridge aloft springs back up in the wake of the
aforementioned shortwave trough. Above normal 500mb heights and
850mb temps may even last through Wednesday. High temperatures
will begin to trend cooler; however, interior temperatures will
be similar to Tuesday. Marine air and low clouds pushing into the
coastal river valleys could also bring significant cooling around
mid week if northwest winds increase offshore over the waters.

Precipitation chances return on Wednesday as a cut- off low
burrows eastward into the dominant ridge. Latest WPC guidances
suggest there is a 40% chance of light precipitation across the
area on Wednesday and Thursday, with 50% on Friday. Overall not
much rain is expected over 3 days (Wed-Fri), generally less than
0.25 inches with locally higher amounts due convection in the
interior. Potential for interior convection/thunderstorms
increases on Thursday with long CAPE profiles around 150-300
J/kg, lifted indices near -1C and PWATS over 200% of normal in the
afternoon/early evening over eastern Trinity, NE Mendo and
northern Lake where low level convergence of upslope winds occur.
Wrap around moisture with above normal precipitable water (PWATS >
200% of normal) and greater CAPE on Friday should yield stronger
storms that may result in heavy downpours and perhaps some small
hail. Profiles are not too favorable to strong and gusty outflow
winds (inverted-V profiles), however a few deterministic models,
namely the ECMWF, indicate higher surface- to-500mb S-SE bulk
shear around 25-35kt and strong multi-cell storm clusters seem
possible in the interior.

Beyond Fri into next weekend, wrap around moisture with interior
showers and thunder remains possible on Fri and Sat if the
eastward progression of cut-off low slows down or stalls over the
area. Another trough may come barreling down from the NW bringing
considerable cooling and perhaps more light precip. Or the ridge
will come back and leave the area in dry stable weather with a
warm up for the interior.


&&

.AVIATION...Thick fog and very low stratus is evident on satellite
data just offshore, but so far this evening VFR conditions have
persisted. Most models show a high chance (75%) of fog pushing in
before sunrise, bringing a period of IFR to LIFR along the post.
There is an 80% chance of at least brief clearing back to VFR during
the day, with a deeper (more likely IFR than LIFR) marine layer
likely to build in Monday night. Stratus impacts will remain
relegated to the immediate coast and near coastal valleys. /JHW


&&

.MARINE...Very gentle to calm northwest winds will persist into
Tuesday. Similarly calm seas will persist as well. Low pressure
slowly passing to the south will strengthen northerly winds mid week.
There is relatively high wind strength uncertainty depending on the
track of the low. The ensemble mean shows gusts only to around 21
kts by Thursday in the outer waters,but there is a 20% chance of
near gale force gusts. Regardless there is little to no swell and
sea will be dominated by whatever short period seas are generated.
/JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
None.
&&

$$

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