textproduct: Eureka

KEY MESSAGES

* Warmer temperatures with additional chances for light rain this weekend. * Stronger storm systems with heavy rain possible starting around or after November 10th.

* Minor to possibly near moderate coastal flooding is likely around Humboldt Bay from November 7th to 10th.

SYNOPSIS

Conditions will trend warmer and drier through the week and into the weekend. Another front will clip the area late Saturday into early Sunday, bringing chances for light rain for isolated areas. The weather pattern continues to look to trend more active mid to late next week.

DISCUSSION

A series of strong NE Pacific cyclones will form and impact regions north of CA in the Pacific Northwest and BC. These storm systems sent a weak front over far NW California Tuesday evening and another one is expected Saturday evening into Sunday. There is a higher chance of rain for the weekend system, with 30-50% chance for over a half inch of rain for N Humboldt to Del Norte. Though the much stronger winds will be farther north over Oregon, some recent model runs have trended the trough farther south, so the wind threat will need to be watched for the Del Norte area. Currently probabilities for gusts over 35 mph are low for the coast and ridges of Del Norte.

The NE Pacific troughs that pass well to the north will amplify ridging over the west. Temperatures will trend warmer in response. Ridging will peak Saturday when highs in some of the interior valleys are forecast to reach the upper 70s to 80 degrees, and this will be 10 to up to 20 degrees above average for the time of year.

The longer term forecast still holds a signal for a more active pattern, with ensembles showing the potential for more impactful storms capable of heavy rainfall and strong winds. Non linear error growth through the farther extended timeframe leads to over- amplification of the large Pacific storm systems in the global models. This is evident in the growing variability in solutions, with half the clusters depicting 1-2 inches of rainfall and the other 50% dry through the 11th through 12th of November timeframe with slightly better agreement later in the 12-13th. Strong southerly winds would also be probable with an atmospheric river type of weather system. JJW

AVIATION...18Z UPDATE

VFR conditions are expected through the day along the North Coast with inland valleys experiencing areas of IFR fog which is expected to burn off by midday. The current offshore winds are expected to shift northerly through the day before calming this evening and switching southerly by dawn tomorrow. Surface fog is possible, yet unlikely tomorrow as the influence of an incoming cold front to the north of the area will likely disrupt any cold pooling at the surface. Inland afternoon winds will be strongest along ridges as a relatively stable atmosphere remains through the day, yet afternoon NNW breezes are forecasted to reach the valley floors. DS

MARINE

The sea state will be dominated by the influence of an incoming cold front to the north of the area through the end of the week. Northerly winds build today as the interior heat creates a relatively week surface pressure gradient. That said, a small craft advisory is still issued for the coastal waters due to steep large NW waves entering the waters mixing with the locally generated short period seas. The NW Swell of 8-10ft @ 13sec will continue through the end of the week before being reinforced with another similar NW swell Saturday morning. As this swell arrives, expect southerly winds to build with the strongest flow in the far northern waters. Near the coastline, offshore winds are expected Saturday morning as well for the North Coast. Light north winds will develop Sunday before southerlies reform before the start of next week. DS

BEACH HAZARDS

An eastward propagating, strong Aleutian low will deliver a second long period WNW swell. The 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 moderate 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!

COASTAL FLOODING

The positive tidal anomaly remains increased again, continuing bring tides higher than predicted. The increased southerly winds brought tides around 1.5 ft higher than forecast Wednesday at the North Spit gauge. Tides are officially forecast to reach 7.4 to 7.5 feet at North Spit on the 7th through 10th of November. The current range of tidal anomalies would bring tides up to and over the advisory level of 8.8 ft, and minor coastal flooding around Humboldt Bay. There will likely be periods of stronger southerly winds through those days, bringing higher confidence to at least minor coastal flooding, and perhaps near moderate.

EKA WATCHES/WARNINGS/ADVISORIES

CA... Beach Hazards Statement from 10 PM PST this evening through Friday evening for CAZ101-103-104-109.

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