textproduct: Eureka

KEY MESSAGES

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

* 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

A weak upper level low off the coast of the Pacific Northwest continues to slowly move northwestward. This troughing pattern has brought a deep marine layer and a weak marine inversion. This brought elevated stratus that crept farther into the interior. This has allowed for interior temperatures to remain about or slightly below normal with most valleys seeing high 80s to mid 90s. The weak marine inversion and light nearshore winds have allowed coastal temperatures to remain above normal with the immediate coast observing mid 60s to low 70s. This is likely to continue today, but confidence wanes somewhat Sunday into early next week. 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

AVIATION...(18Z TAFs)

Coastal stratus has scattered and lifted late this morning, bringing VFR conditions across the area. Stratus is likely to return again tonight bringing IFR to MVFR ceilings to the coastal terminals. There is a chance for occasional visibility reductions overnight at the coastal terminals, but confidence is low. Interior areas are likely to remain VFR for the next 24 hours. /JB

MARINE

Light winds continue across the waters with southerly winds being observed north of Cape Mendocino and northerlies south of the Cape. Seas are dominated by mid to long period northwesterly and southerly swells of 2 to 5 ft. Northerly winds begin to spread through all marine zones Sunday. Northerlies will also increase south of Cape Mendocino Saturday night through Sunday, with sustained winds of 15 to 20 kts likely in the outer waters by Sunday evening. This pattern continues through mid next week. Wednesday, northerly winds increase again across the waters with strong breezes and steep seas expected for the outer waters. /JB

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 is being observed at around 3 to 4 ft at 22 seconds. This 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. A Beach Hazards Statement has been issued through midnight tonight for this threat.

Sneaker waves are relatively large, unexpected waves that arrive without warning. There may be up to 30 minutes between sets of these waves. Relatively mild seas can be followed by breaking waves of up to 10 to 15 ft. Be cautious while at southward facing beaches and stay much farther back from the water. Never turn your back on the ocean! /JB

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None.