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000
FXUS66 KEKA 182110
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
210 PM PDT Thu Apr 18 2024

.SYNOPSIS...Dry weather and mild temperatures are expected to
continue through Friday. A weak cold front will bring a slight
chance of light rain and drizzle to the North Coast on Saturday
followed by breezy northerly winds on Sunday.

&&

.DISCUSSION...It was another pleasant day across NW California
today with above normal high temperatures (mid 70s to mid 80s) for
the interior valleys after another chilly start (low temps in the
mid 30s to mid 40s). Coastal areas were near normal; a couple
degrees either side of 60F. Upper ridge offshore extending
northward into western British Columbia will slowly shift eastward
Friday through Saturday. Large scale sinking associated with the
upper ridge coupled with light offshore wind flow will result in
another stellar day with pleasant interior high temps on Friday.
The one downside is the potential for stratus and fog along the
Mendocino coast on Friday. Signature for a southerly wind reversal
and stratus north of Cape Mendocino in not as pronounced. Low
stratus clouds will probably form offshore over the waters and
spread onto the North Coast Friday night in advance of a weak front.

A weak front associated with a transient shortwave trough will
bring a push low level moisture and perhaps some light rain and
drizzle to Del Norte and northern Humboldt counties, primarily
during the afternoon on Saturday. Otherwise, dry weather and some
cooling of interior high temps are expected in response to breezy
west-northwest winds and greater cloud cover across the interior.

Surface high pressure will build in quickly over the Pacific
Northwest Saturday night and Sunday in the wake of the front.
Breezy northerly winds are forecast to redeveloped over mostly
coastal areas as surface pressure gradients tighten on Sunday.
NBM probabilities indicates a 60-80% chance for wind gusts from
30-40 MPH along the exposed ridges and coastal headlands of Del
Norte/Humboldt Counties on Sunday. Also, gusty west-northwest
winds will most likely develop through channeled terrain in the
interior behind the front Saturday evening.

After a brief period of interior warming and upper ridging, interior
temperatures are forecast to trend down mid to late next week as
another upper-trough-complex impacts the west coast. The magnitude
and rate of cooling remains highly uncertain at this point with
25-75th spreads on the order 10F for high temps and 5F for low
temps. Current forecast is for near normal temperatures; highs in
the 60s and lows mostly in the 40s. There are subtle indications
for convection across mainly Trinity County on Tuesday as an upper
trough with limited moisture generates instability.

Potential for precip (showers) will also increase mid to late next
week, though amounts will most likely wont be very much with RAW
ensemble probabilities of 20% to 30% for > 1 inch of rain in
24-hours for the western slopes of Del Norte and northern
Humboldt. Stay tuned. DB

&&

.AVIATION...VFR conditions prevail this afternoon at all
terminals. Mid to high level clouds will increase from the west
throughout the day. Though the northerly winds have relaxed today,
a dry, well-mixed boundary layer continues to thwart stratus
formation through this TAF period. Further easing of the northerly
winds, along with developing coastal return flow eddies, will
begin to increase stratus chances starting later Friday. /JJW

&&

.MARINE... Northerly winds will continue to trend lower today. Steep
seas are also on the way down, and will drop below 7 feet in all
zones into early Friday morning. Winds will become light and
variable in the nearshore inner zones tonight, with periods of
southerly return flow. The northerlies will sharply increase
Saturday afternoon behind a passing front. The northerly winds will
further increase Sunday into Monday when Gale conditions now seem
probable. There is currently 85 to 95% for gusts over 34 kt over the
southern outer waters, and 65 to 75% for the northern outer zone
Sunday afternoon. Other than small 2-3 foot long-period southerly
swells, and a small, mid-period swell over the weekend, the sea
state will be dominated locally generated short-period seas. /JJW

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PDT Friday for PZZ470.

     Small Craft Advisory until 9 PM PDT this evening for PZZ475.

&&

$$

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