textproduct: Eureka

SYNOPSIS

Dry, calm, and foggy weather will persist through the weekend. Wetter weather will finally return next week with period of light to moderate rain and wind focused along the North Coast early in the week.

DISCUSSION

KEY MESSAGES:

-Calm and dry weather with nocturnal fog through the weekend.

-Moderate rain (1 to 2 inches at lower elevations) most likely (70% chance) to impact the North Coast early next week. Mildly enhanced (gusting 35 to 45 mph) southeast wind along with the rain.

-Potential for a stronger storm late in the week.

WEATHER PATTERN OVERVIEW: Broad high pressure and gentle offshore flow will continue Friday and through the weekend. This will continue to promote a very shallow but patchy marine layer along shore with shallow fog overnight. During the day, unseasonably warm conditions will continue with near record breaking highs in the mid 70s expected to continue Friday around Ukiah. Otherwise conditions will continue to be unseasonably dry and calm.

There is high ensemble confidence that a wetter pattern will finally return early next week, brining the first wetting precipitation for December across NW California. A weak but consistent atmospheric river will most likely (70% chance) impact the area beginning late Monday through mid week. There does remain a 30% chance that rain will remain north of the area with little precipitation for the North Coast.

There is strong indication that conditions will remain much warmer than normal during the wet period, eliminating any winter weather concerns and generally limiting the thunderstorm or higher end rain rate potential. Rain will be mostly focused along the North Coast. Although much more rain than recently, rain amounts will be very typical for this time of year. Most likely rainfall at lower elevations along the North Coast between Monday evening and Wednesday will be between 1 and 2 inches with enhanced rain amounts at higher elevations of 2 to 4 inches. Rain amounts will be much less for the southern half of the area with less than 0.5 inches of rain most likely in Lake County and around the Russian Valley. Given recent dry weather, even rain rates aligning with model outliers will most likely result in little flood risk.

Beyond rain, enhanced southeast wind will briefly arrive alongside the rain. Similar to the rain though much windier than any conditions over the past several weeks, conditions will generally be typical for December. Peak wind gusts at lower elevations will most likely be 25 to 35 mph with only a 20% chance of impactful gusts over 45 mph on high coastal ridges. Winds gusts will most likely be strongest Monday and Tuesday.

There is generally high (80% of ensemble members) that a wetter pattern will continue through the end of December. Long range forecasts have placed a high risk for a moderate to strong atmospheric river near the end of next week. This could translate into heavy rainfall of 2 to 6 inches and wind gusts over 60 mph. There remains, however, very high ensemble variability with a large possibility that any stronger storms continue to stay north of the area. /JHW

AVIATION...(06z TAFs)

Variable conditions at the coastal terminals with shallow fog/mist through this morning, followed by mainly VFR/MVFR with visibility reduction in haze at ACV and CEC. Prevailing VFR at UKI through the TAF period. Winds remains light.

MARINE

Moderate to fresh northerly winds across the outer waters, while light to gentle for the inner waters.Northerly winds are expected to gradually diminish throughout the day. Short-period wind waves in the southern outer waters will expand into the northern outer waters this morning, resulting in hazardous conditions for small crafts through tonight. Winds and seas greatly improve Saturday with calm to light southerly winds and fading short period and long period waves. Southerly winds are forecast to strengthen late Sunday with increasing influence from a Northeast Pacific trough. Chances for Gale strength gusts increase Monday, particularly in the northern waters. /ZVS&JJW

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PST Saturday for PZZ470.

Small Craft Advisory until 3 PM PST this afternoon for PZZ475.