Westport, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

333
FXUS66 KEKA 111404
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
604 AM PST Wed Dec 11 2024

.SYNOPSIS...A cold front is bringing rain to Del Norte county
this afternoon and this will quickly spread south and east
reaching Lake county by the evening. Thursday showers are
expected, mainly in the north. Friday and Saturday the next
weather system is expected to bring heavy rain, mountain snow and
strong winds. A brief break is expected Sunday with another
weather system on Monday.

&&

.DISCUSSION...A fairly robust cold front is approaching this area
this morning. It is expected to move onshore this afternoon and
evening. At this point it looks like rain will start around mid
afternoon in Del Norte county and quickly move south reaching Lake
county by early evening. Rainfall amounts have continued to trend
upwards and now ranges from around an inch along much of the
coast, up to nearly 2 inches in the mountains, and 0.50 to 0.75
inches in the drier interior valleys. The dry air in place in
Trinity county will likely keep the snow levels lower in the
northeastern portions of the county. Went with the NAM and GFS
snow levels which brought them down to around 2500 to 300 feet
from Oregon Mtn summit on Hwy 299 to the north and east. This
will likely be heavy wet snow, but 3 to 5 inches is possible as
low as 3000 feet with up to an inch down possibly as low as 2000
feet. Gusty winds are also expected with this system with the
higher peaks and exposed coastal areas of Humboldt and Del Norte
counties seeing gusts of 20 to 30 mph Wednesday late in the
afternoon and evening. Thursday showers are expected behind the
main front. Snow levels will be lower across the area this these
showers, likely dropping to around 4,000 feet or even slightly
lower for much of the area. Models are still not in very good
agreement on how much rain will fall with these showers.

Friday the next system starts to move into the area. The models
are showing a warm frontal boundary out ahead of the main cold
front. Rainfall amounts for Friday look to rain range from over
an inch in the King Range to a quarter of an inch in southern Lake
county. This looks like a highly favorable pattern for low
elevation snow. So have lowered snow levels to 2500 to 3500 feet
across most of the inland areas Friday morning. Breezy south
winds are expected, but these look to mainly be over the higher
terrain due to the fairly stable temperature profile.

Friday evening and Friday night the cold front is expected to
bring strong winds and heavy rain to the area. 925 MB winds on
the 06Z GFS reach 60 KT at Cape Mendocino. Rainfall amounts from
Friday morning through Saturday afternoon look to be around 2 to
4 inches across much of the area, although eastern Lake county
will be closer to 1.5 inches. This may cause some minor flooding
due to the fairly short period of time that it is expected to fall
over. This flooding is expected to be exacerbated around they
bays where streams will have trouble draining during high tide.
Snow levels Friday night into Saturday morning in eastern Trinity
county may be as low as 2500 feet and over a foot of snow is
possible. These will start to rise Saturday afternoon.

Sunday there is expected to be some lingering showers around, but
overall it looks like it will be a break in the rain. Another
fairly strong system is expected on Monday with additional rain,
wind and snow. At this point it looks weaker than the Friday
night system, but it is still 6 days out. MKK

&&

.AVIATION...VFR conditions currently present at all TAF sites. Light
offshore wind is keeping clouds at bay. This morning, the forecast
calls for wind shear at 2kft AGL along the coastal terminals due to
an approaching cold front that will pass over the area today.
Multiple models suggest that a low-level jet of 40-50kts will be
present over the coast this evening and tomorrow early in the
morning due to the frontal forcing. This front is also forecasted to
bring vicinity showers and rain which can sporadically cause limited
visibilities in the late afternoon/early evening. Visibilities show a
90% of remaining over 3SM through the TAF period according to model
guidance. Winds are expected to be southerly and strengthen in the
early afternoon, with gusts possible to ~20kts at coastal
terminals.

&&

.MARINE...Winds today building from the south to gale force in the
northern outers with gusts expected around 35-40kts. These winds are
forced by the passing cold front that will sweep over the area
through the day. In the wake of this front, winds are expected to
remain strong, yet switch direction as we enter the cold sector of
the frontal system. A low-level jet behind the front at the 925mb
pressure level has the possibility to mix down leading to the Gale
warning remaining in effect until Thursday afternoon.

Waves today will be dominated by a NW swell and southerly wind
waves. This swell is expected to wane through Thursday before
another pulse of NW swell arrives to our waters on Friday. Southerly
wind waves will be present on Friday as well as second frontal
system arrives to our area from the NW Pacific. Waves are expected
to remain fairly large (>10ft sig. height) from today into the
weekend with the peak heights over +20ft on Saturday.

&&

.BEACH HAZARDS...Multiple wave groups of long period westerly swell
still persist in the coastal waters this morning. These wave groups
present a moderate risk of sneaker waves through the morning today.
Be cautious visiting beaches and jetties this morning, as relatively
large and unexpected waves could sweep in without warning. Stay much
farther back from the water and never turn your back on the ocean.
JB

&&

.COASTAL FLOODING...High astronomical tides are predicted from
Thursday through early next week. Winds will turn southerly again
Thursday night. Some minor flooding around Humboldt Bay is
possible by Friday morning. Astronomical tides will be 8.45 at
the North Spit Tide gauge. It is likely we will have nearly a 0.5
feet of water over over the astronomical tides resulting in water
levels of 8.9 or so above MLLW. This exceeds the threshold of 8.8
when flooding starts. Saturday astronomical tides will be 8.6 and
by this time there could be nearly a foot of additional water
expected resulting in levels around 9.6 feet and more widespread
flooding in the low lying areas around Humbodlt Bay. The large
surf on top of these high tides may allow waves to wash over the
highway 1 and highway 101 where they are exposed to the waves. MKK

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement until noon PST today for CAZ101-103-
     104.

     Winter Weather Advisory from 6 PM this evening to 10 AM PST
     Thursday for CAZ107.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory from 3 PM this afternoon to 9 PM PST
     this evening for PZZ450.

     Small Craft Advisory until 3 AM PST Thursday for PZZ455-475.

     Small Craft Advisory until 3 PM PST this afternoon for
     PZZ470.

     Gale Warning from 3 PM this afternoon to 3 PM PST Thursday
     for PZZ470.

     Gale Warning from 3 AM to 3 PM PST Thursday for PZZ475.

&&

$$

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