textproduct: Eureka

KEY MESSAGES

* Moderate risk for sneaker waves along the Lost Coast and Mendocino Coast through Wednesday.

* Elevated fire danger through Tuesday for interior areas due to breezy afternoon winds.

* Near to slightly below normal interior temperatures expected through the middle of next week.

* Coastal stratus likely to form each night and clear each afternoon through at least the middle of next week.

* Hot interior temperatures likely late next week.

SYNOPSIS

Near to slightly below normal temperatures likely for the interior areas, while near to slightly above normal coastal temperatures are likely for the coastal areas for the coming days. Breezy afternoon winds elevate fire danger in eastern Trinity, eastern Mendocino, and Lake counties. Hot interior temperatures return late next week.

DISCUSSION

The weak marine inversion and light nearshore winds allowed coastal temperatures to remain above normal with the immediate coast observing mid 60s to low 70s, and tying a record at WFO EKA on Woodly Island. Winds offshore slightly increase and turn more northerly, which could knock coastal temperatures back towards normal (low to mid 60s); however, the weak marine inversion remains in place through mid next week. The Mendocino Coast will see breezier afternoon winds which will support closer to normal temperatures.

The troughing pattern has also brought breezy afternoon winds of 20 to 25 mph in the interior areas, mainly in the higher elevations and channeled terrain (such as Clear Lake and the Trinity River valley). Low afternoon relative humidities in Trinity, eastern Mendocino, and Lake Counties along with these winds brings an elevated fire weather threat.

There is high confidence in high pressure rebuilding over the area late next week. NBM is showing moderate to high probabilities for high temperatures in the triple digits for most interior valleys Friday into the weekend. JB/JJW

AVIATION

(06Z TAFS)..The low level inversion will remain at a weakened state while broad NE Pacific troughing deepens the marine layer slightly. The setup is not favorable for long duration shallow stratus and visibility obscurations; however, soundings show a very shallow saturated layer below the deepened ceiling. MVFR to IFR levels are probable, though statistical guidance (MOS) introduces some brief fog and more solid coverage of LIFR ceilings. Given the mixed signals, there is low confidence on what layer will largely persist. The weak inversion is expected to allow for another day of full clearing Sunday afternoon. /JJW

MARINE

The sea state is dominated by a small 3 to 4 foot long period southerly swell and some small mid period westerly and northerly swells. A second reinforcing long period southerly swell will arrive Tuesday. Winds will remain very light, only up to 4 to 8 kts Sunday afternoon north of Cape Mendocino. South of the cape, northerly winds of 10 to 15 kts, and locally up to 20 kts around the cape will develop thru Sunday afternoon. The southern zones will continue to see slightly higher winds Monday before the northerlies trend higher in all waters starting Tuesday. Localized areas of gale conditions will develop in the expansion fan around Cape Mendocino. /JJW

FIRE WEATHER

Breezy westerly winds will continue in the afternoons for interior areas and may be particularly breezy with gusts of 20 to 25 mph over the ridges and channeled terrain in eastern Trinity, northeast Mendocino, and Lake Counties. Afternoon relative humidities remain low in these areas with minimum values in the teens and 20s. Outside the higher elevations of Lake County, which has been observing moderate to poor overnight recoveries, most areas are likely to see good overnight recoveries. This pattern continues through at least mid next week with only minor fluctuations in wind and RH each day. Closer to the coast, a deep marine layer will bring high RH and perhaps stratus and/or fog into the river valleys. Afternoon RH ranges from 70s to 80s at the immediate coast to 30s and 40s in interior Humboldt, Del Norte, and western Mendocino Counties. Hot temperatures return late next week. /JB

BEACH HAZARDS

A long period southerly swell, up to 22 seconds, has built in from tropical systems in the Eastern Pacific. A second reinforcing long period southerly swell will arrive Tuesday. These energetic swells will bring a low to moderate risk of sneaker waves that would be most hazardous on steep, south and southwest facing beaches along the Lost Coast and Mendocino Coast.

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! /JJW

EKA WATCHES/WARNINGS/ADVISORIES

CA... Beach Hazards Statement through Wednesday afternoon for CAZ104-109.

NORTHWEST CALIFORNIA COASTAL WATERS... None.