Marine Weather and Tide Forecast for Westhaven-Moonstone, CA

SYNOPSIS
Warm and dry weather is expected to continue today and early Saturday. Southerly winds are expected to increase Saturday afternoon with some slight rain expected in Del Nort county with some spreading south into Humboldt county overnight.
Dry weather is expected to return Sunday. More light rain is possible in the north Monday through Wednesday. The potential for heavier rain increases late in the week.



DISCUSSION
Saturday morning high clouds start to move into the area as cold front approaches the area. This is expected to bring some rain to Del Norte county by the afternoon or evening. This is expected to spread south in the evening into northern Humboldt county. Farther south rainfall amounts are expected to diminish quickly. The southerly winds with this system look to be stronger than we have seen with previous systems. This may enhance some upslope areas such as the King Range and portions of south Fork Mountain. Overall rainfall amounts look to be less than an inch in Del Norte county and diminish to the south and east. Mendocino, Lake and Trinity counties are generally expected to just see a mix of sun and clouds as well as a cooler temperatures with this system.

Rain is generally expected to come to an end on Sunday with the system dissipating as it moves inland. Cloudy skies are expected to linger in Humboldt and Del Norte counties. High temperatures are generally expected to remain in the 60s.

Monday through Wednesday it looks like the weather systems will mainly remain north of California, although some light rain may occasionally drift south into the area. This will likely bring a mix of sun and clouds to the area and temperatures will likely be in the 60s to low 70.

Late in the week the models are starting to show more confidence in the heavier rain dropping south into the area. The models have been showing rain moving south on day 8 or so for the past week or two and this is not unusual in the fall season. The trick is when it will actually move farther south and bring the rain. The increased probabilities are starting to show up at day 7. So it looks like northwest California might be getting closer to some more significant rain. Stay tuned. MKK



AVIATION
VFR conditions are expected through the rest of the day into this evening. Light winds are expected today as a cold front passes to the north of the area. Visibilities could be degraded for areas near the ocean due to large breaking waves causing airborne sea spray to flow over terminals. This evening, southerly winds are likely to develop ahead of the frontal passage. No rain is expected for NW CA through this time however. Low clouds are possible near the CA-OR boarder possibly creating MVFR conditions through dawn with increasing southerly winds. Ridgetops are also expected to have gust winds and LLT is to be expected tomorrow on approach within the TAF area.



MARINE
Northerly winds have begun to eat for all areas that are no directly downwind of Cape Mendocino. This is leading to a sea state that is primarily dominated by one moderately large NW swell at 10ft@16s. This swell is expected to continue through the rest of the day into Saturday night. Ocean winds will shift to southerlies this evening as a cold front passes to the north impacting southern Oregon. Southerly winds will be strongest directly north of Cape Mendocino and in the far northern waters where strong breezes to near gale force gusts are likely.

Come Sunday, a second much larger NW swell is expected to enter the coastal waters. Current models have consistently shown a swell between 18-20ft@15seconds arriving by dawn. That said, models have been lower than the observed waves for the past few incoming swells and a larger swell height is possible, especially as this wave group first arrives to the waters. A hazardous seas watch has been issued for all of Sunday due to this large, steep wave group.
This swell looks to lower down to the mid teens as moderate southerly breezes develop through the start of the coming week.

BEACH HAZARDS
An incoming strong Aleutian low pressure system will deliver multiple long period WNW swells over the next few days.
The first swell will arrive late Thursday with periods up to 20 seconds. The swell will peak at around 11 to 13 ft at 17 seconds Friday, bringing a low to moderately increased risk for sneaker waves.

Sneaker waves are a unique hazard, with up to 30 minutes between waves. Large, unexpected waves can sweep across the beach without warning, sweeping people into the sea from rocks, jetties, and beaches. These sneaker waves can also move large objects such as logs, crushing anyone caught underneath. Even ankle to knee deep water can knock you down and drag you out when a sneaker wave hits.
Pay attention and stay above the high water line and any wet sand to stay safe. If the ground is wet, waves have surged there recently.
Stay safe and never turn your back on the ocean!

A second swell is expected to arrive Sunday morning creating large breaking waves for NW facing beach through the day. Waves could be as large as 22-24ft. A High Surf Advisory is likely as this forecast seems to remain on track with large swell and waves. Extra caution is advised near beaches this weekend due to the increased swell activity. Northern California beaches have yet to had many swells this large this season which means that the beaches have yet to respond to the extra force allowing wave energy to travel further up the sand than is typical for the winter season. Stay safe by being aware of these potential hazards.



EKA WATCHES/WARNINGS/ADVISORIES
CA...
Beach Hazards Statement until midnight PST tonight for CAZ101-103-104-109.

High Surf Advisory from 4 AM to 10 PM PST Sunday for CAZ101- 103-104-109.

NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 3 PM PST Saturday for PZZ450-455- 470-475.

Hazardous Seas Watch from late Saturday night through Sunday evening for PZZ450-470.