textproduct: Eureka

KEY MESSAGES

* A few light showers are expected Tuesday morning in Del Norte and northern Humboldt counties.

* Valleys of Lake county are forecast to see near freezing or freezing temperatures again Tuesday morning.

* Minor coastal flooding expected through Thursday at high tide, mainly around Humboldt Bay.

SYNOPSIS

The lingering showers in Humbodlt and Del norte counties are expected to diminish this evening. Another weak front is expected to bring more light rain to Del Norte and northern Humbodlt counties Tuesday morning. Cool and mainly dry weather is expected Wednesday through Friday with another chance for light rain over the weekend.

DISCUSSION

A weak front moved through last night bringing some light to moderate rain to Humboldt and Del Norte counties. Showers are lingering this afternoon over the higher terrain, but are expected to diminish this evening. It looks like clouds will sink into many of the valleys tonight and this is expected to keep the temperatures from getting too cold. The exception may be Lake county so have added a frost advisory to Lake county. This may need to be expanded into Mendocino county if skies clear more than expected. Early Tuesday a weather system moving by to the north has strengthened slightly and now it looks like this will bring some rain to areas north of Ferndale in Humboldt county and in Del Norte county. Rainfall amounts are expected to be less than a quarter of an inch and likely less than a tenth of an inch. Again, this rain is not expected to make it very far inland or south with Trinity, Mendocino and Lake counties remaining dry. This rain and is expected to come to an end in the evening.

Wednesday through Friday an upper level trough is expected to remain over the region, but at this point the weather systems are expected to remain north of the area. This could change and one of the weather systems could drop farther south bring some light rain to northern portions of the area. High temperatures expected to remain in the 50s in the north and the 60s in the south. At this point Wednesday looks like it will be the most likely to clear out in Humboldt and Del Norte counties, although confidence still remains moderate on this.

The NBM shows Saturday as the next time northwest California may see rain, however even then probabilities for over a tenth of an inch remain around 25 percent or less. Next week models are still showing the potential for heavier rain, but the ensembles generally show it now holding off until the middle of the week. MKK

AVIATION

A dry and cold air mass advecting across the area today combined with slight offshore flow has kept the coast clear to VFR conditions all day today. VFR conditions will most likely continue overnight with only patchy ground fog expected thanks to clear skies. Moisture from recent rain did support extensive valley fog this morning, but no terminals were impacted and less interior fog coverage is expected tonight. VFR conditions will most likely continue all day Saturday with dry air remaining in place. /JHW

MARINE

In the wake of a passing cold front, gale force north winds have persisted all day today in the outer waters. Winds have also been strong near shore with hazardous short period seas up to 12 feet even pushing near shore. Despite the front, there is no major swell to speak of with short period seas dominating the sea state.

Winds will weaken and pull back forms shore Saturday with mostly calm winds in the inner waters by early afternoon. Short period seas will fall in response. below 10 feet by mid morning and below 6 feet by the evening. Even in the out waters then mostly calm to gentle north and west winds will persist Sunday through early next week with only a very minor south swell forming the sea state. /JHW

Coastal Flooding

Water levels this morning reached 9.1 ft above MLLW at the North Spit. This brought some minor flooding to low lying areas of King Salmon and the Arcata bottoms. This was again with an anomaly of 1.1 to 1.2 feet above astronomical tides. The surge model shows a similar anomaly on Tuesday and light southerly winds are expected to persist north of Cape Mendocino Tuesday morning. So with an astronomical high tide of 8.04 feet on Tuesday, expect water levels will reach 9.1 or 9.2 and cause slightly more flooding than this morning. So have issued another coastal flood advisory.

Wednesday the northerly winds are expected to start to strengthen and expand north. This may start to diminish the anomaly or keep it steady. This will be the highest astronomical tide at 8.06 ft. This will likely bring at least minor coastal flooding and possibly moderate coastal flooding. This will mainly be around Humbodlt Bay with little expected outside the bay unless there are large waves. Arena Cove is also expected to see water level reach the highest astronomical tide levels. Waves are only expected to be around 6 to 7 feet at 11 seconds so am not expecting impacts on the Mendocino coast at this point, but this will need to be monitored. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... Coastal Flood Advisory from noon to 3 PM PDT Tuesday for CAZ103.

Frost Advisory from 1 AM to 9 AM PDT Tuesday for CAZ114-118- 120.

NORTHWEST CALIFORNIA COASTAL WATERS... None.