textproduct: Eureka

SYNOPSIS

Colder than average conditions will persist again tonight through Friday morning. Otherwise, conditions will generally remain calm and slowly dry and warm into early next week.

DISCUSSION

Skies have gradually cleared through the day as the few remaining showers have diminished. The day started with some snow evident as low as 1500 feet but no real impacts have been reported. Otherwise, cooler and drier air has pulled over the area under the influence of north wind. Wind shifting offshore overnight will further promote cold and dry conditions, even along the coast. There is a 50 to 70% chance of lows below 30 around Humboldt Bay tonight with many interior valleys solidly in the mid 20s. Such conditions are much cooler than average.

Otherwise, weak ridging will slowly build into the region this weekend and into early next week. Gradual warming will occur by late this weekend and build into mid next week. A very weak upper level wave around Sunday could produce midlevel clouds and very light coastal drizzle, but otherwise skies will be mostly clear. Southeast winds will most likely inhibit any strong marine layer formation. Above average temperatures are forecast by Tuesday with some daytime interior highs in the low 70s by early next week. In contrast to the last couple of weeks, there is very little chance of rain with less than 10% of ensemble members indicating any chance for wetting rain late in the week. /JHW

AVIATION...(18Z TAFs)

Cloud cover has largely subsided across the area with only a few lingering showers being observed over the waters. VFR conditions are being observed at all the terminals. Breezy northerly winds are possible at all terminals early this afternoon before subsiding overnight. A low level wind shear threat at UKI will likely subside by early this afternoon. Offshore flow tonight is expected to keep skies clear across the area, aside from stratus and fog in the interior valleys. NBM is showing less than a 10% chance for IFR conditions at UKI tonight, but with ample moisture it is not out of the question for some patchy fog to develop around sunrise. JB

MARINE

A large long period swell has filled in and peaked this morning around 22 ft at 17 seconds. This swell will subside over the coming days, but combined seas are likely to remain above 10 ft through at least Friday afternoon. Winds have started to ease as well as the pressure gradient weakens, but are still likely to remain breezy in the lee of Cape Mendocino. Generally, gusts of 10- 20 kts are expected across the waters and could reach around 30 kts in the lee of Cape Mendocino this afternoon and evening. Winds subside tonight and turn southerly ahead of a trough to the north of the area. Winds are likely to be fairly light, through gusts could reach up to 15-20 kts possible by Saturday in the northern waters. A westerly swell will fill in Saturday, though combined seas are likely to remain below 10 ft. Another, larger westerly swell at around 12 ft at 17 seconds fills in Sunday, returning elevated seas. Winds turn northerly but remain fairly light early next week. JB

BEACH HAZARDS

A large northwesterly swell has peaked at around 21 to 22 ft this morning, producing breaking wave heights of 22 to 25 ft. The High Surf Advisory remains in effect through 10 PM this evening as the swell begins to subside. Stay much farther back from the ocean and avoid steep beaches and jetties. Remember, never turn your back on the ocean!

On Sunday, another long period westerly swell originating from a low near the Aleutians fills in at around 7 ft at 20 seconds and peaks around 12 ft at 17 seconds. Should this swell fill in as forecast, there will be a moderate sneaker wave risk for the area on Sunday and into early Monday. JB

EKA WATCHES/WARNINGS/ADVISORIES

CA... High Surf Advisory until 10 PM PST this evening for CAZ101- 103-104-109.

Cold Weather Advisory from 2 AM to 9 AM PST Friday for CAZ103-113-115.

NORTHWEST CALIFORNIA COASTAL WATERS... Hazardous Seas Warning until 10 PM PST this evening for PZZ450-455-470-475.