Area Forecast Discussion

KEY MESSAGES

* Warmer temperatures with a couple slight chances for light rain this afternoon and evening and again this weekend. * Stronger storm systems with heavy rain possible starting around or after November 10th.

.SYNOPSIS

Conditions will trend warmer and drier through the week and into the weekend. A couple fronts will clip the region this evening and Sunday, bringing chances for light rain. The weather pattern may trend more active mid to late next week.

DISCUSSION

Rain showers have moved out of the area early this morning with lingering cloud cover slowly subsiding. Rainfall totals ranged from around 0.1 to just under a half of an inch over eastern Trinity, Mendocino, and Lake Counties, with just a few hundredths being reported elsewhere. Lingering cloud cover and ample moisture will likely support areas of valley clouds and fog, which will also limit the potential for frost.

A series of strong NE Pacific cyclones will form and impact regions north of CA in the Pacific Northwest and BC. These storm systems will send a couple weak, clipping fronts this evening and again Saturday/Sunday. Light rainfall will be possible, but totals look to be low. There is a higher chance of rain for the weekend system, with 40-50% chance for over 0.3 inch of rain for N Humboldt to Del Norte. This period will have to be watched for some enhanced southerly winds however, looking at 925mb winds. There is currently around 30% chance for gusts over 30 mph for the Del Norte ridges and coast Sat-Sun.

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. Chances for over an inch in 24 hours are 45 to 55% over that period. Strong southerly winds would also be possible. JJW/JB

AVIATION...(6Z TAFs)

Showers have moved out of NW California and skies have started to clear. VFR conditions are likely at all terminals overnight, aside from 20-30% chances for ground fog from recent rains. Any low ceilings will lift and scatter shortly after sunrise. A weak front moving north of the area will bring a roughly 30% chance of rain in the afternoon and evening to the Del Norte Coast. JB

MARINE

Winds diminish and turn northerly today while seas subside as both short period seas and a large northwest swell decays. Northerly winds increase again Wednesday night into Thursday with 20 to 25 kt sustained winds expected south of Cape Mendocino. Moderate winds are possible north of the Cape Thursday afternoon, as well. Another long period northwest swell at around 10 to 11 ft arrives Thursday, which will keep the sea state elevated. Combined seas of 12 to 14 ft are possible as this swell combines with steep seas. Northerly winds peak Thursday and gradually subside again Friday and into the weekend. JB

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 12 ft at 17 seconds Friday, bringing another 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 has increased again, continuing bring tides higher than predicted. The increased southerly winds brought tides 1.8 ft higher than forecast Tuesday at the North Spit gauge. Tides are officially forecast to reach 7.4 to 7.5 ft 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 some moderate.

EKA WATCHES / WARNINGS / ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PST early this morning for PZZ470-475.