textproduct: Eureka

SYNOPSIS

Cool and clear conditions will continue today. Winds turning onshore will likely help form a marine layer early Sunday with light drizzle and rain along the North Coast. Clearer conditions will return early next week alongside another risk of interior frost.

DISCUSSION

Offshore flow continuing overnight combined with drier air may allow for patchy frost formation in interior valleys of Trinity and NE Mendocino counties early this morning. That said, the addition of moisture to the environment from the recent rain is already enabling the formation of fog, which reduces the likelihood of frost formation. Frost concerns through this morning remains low (less than 10% via HREF/REFS probabilities).

Closer to the coast, unstable conditions will make any marine layer formation unlikely leading to clear skies with the exception of radiation fog forming in the coldest lower elevations spots. Cold air will quickly be pulled east of the area with high pressure and offshore flow generating quick warming and drying into the weekend. Sunday will likely promote some coastal stratus formation. Interior highs will generally return to the mid 60s.

Most ensemble members show a weak trough moving onshore well north of the area Sunday night through Monday morning. Most members show light rain and drizzle along the North Coast in Del Norte and Humboldt counties with a 90% chance of at least trace rain amounts in Crescent City and an increasing probability (~15-20%) of any amounts over 0.3 inches. In the Humboldt Bay area, there is about a 40% chance of no rain at all and only a 20% chance of greater than a wetting rain (>0.10"). High pressure will then again most likely briefly build with about 70% of ensemble members showing another cold, cutoff low storm system entering the area late next week. Ensemble clusters are also hinting at a deep trough forming over the NE Pacific next weekend. /JHW&DES

AVIATION...(6Z TAFs)

Offshore flow is promoting VFR conditions at the terminals this evening. VFR conditions are likely to continue overnight, but there is some potential for patchy ground fog to briefly cause LIFR impacts. Any fog and clouds will lift and scatter shortly after sunrise. Winds remain light and mainly from the north. Weakening offshore flow ahead of a front moving through early Sunday will promote the return of the marine layer Saturday evening. So far, models show this as relatively deep with MVFR ceilings likely. JB

MARINE

Northerly winds continue into Saturday and peak in the afternoon with gusts of 20-30 kts in the outer waters. Nearshore, wind gusts peak at 10-20 kts in the afternoon. Seas remain elevated as steep wind waves combine with large long period WNW swells. Combined seas may reach 12-15 ft this afternoon and evening. Winds ease Sunday as a weak front passes through the area, but northerly winds return behind the front Sunday night into Monday. Combined seas may temporarily drop below 10 ft Sunday night, but are forecast to exceed 10 ft again as winds build. Milder conditions return by Tuesday evening and continue through midweek. JB

BEACH HAZARDS

A series of long-period WNW swells will fill in starting Saturday morning. These will pose a moderate risk of sneaker waves through the day Saturday and Sunday. Breaking wave heights may reach 17-19 ft. Be cautious visiting beaches and jetties and remember to never turn your back to the ocean!

EKA WATCHES/WARNINGS/ADVISORIES

CA... Beach Hazards Statement through Sunday evening for CAZ101- 103-104-109.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 7 AM PST Sunday for PZZ450-470.

Small Craft Advisory until 3 PM PST Sunday for PZZ455-475.