textproduct: Eureka

KEY MESSAGES

* Interior Valleys are expected to see a another chilly morning on Sunday morning with near freezing or freezing temperatures, while closer to the coast low clouds may limit the frost.

* Light rain is expected Sunday evening through Monday, mainly in Humboldt and Del Norte counties.

* Coastal flooding is possible Sunday, but more likely Monday through Wednesday at high tide, mainly around Humboldt Bay.

SYNOPSIS

Dry weather will continue through tonight and much of Sunday. Another chilly morning is expected Sunday morning. There is a chance for rain in Humboldt and Del Norte counties Sunday evening through Monday. A persistent upper level trough is expected Tuesday through Thursday bringing highs only in the 60s or cooler. Rain is possible with chances increasing late in the week in the north.

DISCUSSION

High pressure over the area is bringing clear skies and dry conditions. Another chilly night is expected in many of the valleys. Have issued a frost advisory for Mendocino and much of Lake county. If the northern valleys of Mendocino county remain clear they may see freezing temperatures and this will need to be watched. The same will be true in Humboldt and Del Norte counties. Currently clouds look more likely in these areas so have not issued frost advisories there. Farther north in Trinity county an agricultural killing freeze has occurred. Thus, frost advisories and freeze warnings have been suspended for this winter season for Trinity county.

Sunday high clouds are expected to start moving into the area ahead of an upper level trough and associated frontal boundary. Rain is possible as early as late Sunday afternoon in Del Norte county. However this is more likely to start Sunday evening in Del Norte county and spread south overnight into Humboldt county. Rainfall amounts in Del Norte county are expected to range from a half inch to an inch. Humboldt county may see close to a half inch near Del Norte county with less than a tenth of inch in southeastern Humboldt. Eventually some may make farther south and east, but only a trace to a few hundredths is expected. There is a small chance for some thunderstorms late Sunday night in Del Norte county, but confidence is low on this and models have been trending the upper level low farther making it less likely.

Tuesday and Wednesday are generally expected to see dry weather, however it is a troughy pattern. This could bring a few showers, especially to the coastal counties. A mix of sun and clouds is likely in this pattern. This all is expected to keep temperatures in the 50s or 60s. Starting on Thursday most of the models are showing some rain, although the amounts vary on the clusters. The probability of over a half inch for any particular 24 hour period is less than 20 percent through late next week. Early November the models and the CPC forecast are starting to show the potential for a wetter pattern by November 3rd. MKK

AVIATION

High pressure continues to bring mostly clear skies and VFR conditions as well as generally light winds. Tonight there is the potential for some low clouds to develop along the Humboldt and Del Norte coasts. The models show these may be in the MVFR range. In general confidence is low on the return of stratus as there is currently none on satellite anywhere nearby and probabilities are 30 to 50 percent. Areas that do see clouds return are likely to see skies clear out again by midday. Late in the afternoon or evening an approaching frontal boundary is expected to start lowering the CIGS as rain approaches Del Norte county. MKK

MARINE

Winds and waves are expected to continue to diminish tonight. Sunday these winds are expected to gradually become southerly as a front approaches the area. These southerly winds are expected to remain light, only around 10 to 15 kt. A few models show stronger winds in the northern waters and this will need to be watched as it gets closer. Monday night into Tuesday the winds are expected to turn northerly again. These look to be slow to increase only reaching 20 kt in the southern water by Tuesday night. These are expected to continue to increase on Wednesday before diminishing again late in the week. Winds are expected to be mainly wind driven but combining with a small northwest swell around 5 to 7 feet. MKK

COASTAL FLOODING

High astronomical tides associated with the full moon will bring chances for coastal flooding around Humboldt Bay starting as early as Sunday with chances continuing through next week. Astronomical tides at the North Spit tide gauge reaches 7.49 ft MLLW on 11:26 AM Sunday. As the northerly winds have diminish the current tidal anomaly has increased to 1.1 feet for todays high tide. The northerly winds are expected to continue to diminish tonight and Sunday. If the anomaly increases to just 1.3 feet minor flooding may occur. Monday the astronomical tide increases to around 7.8 feet. The anomaly is expected to increase as well and this could easily bring water levels to around 9.0 feet. Tuesday the winds start to turn back to the north. This may start to diminish the anomaly or keep it steady. This will be the highest astronomical tides, and highest chances for coastal flooding, are forecast to be on Tuesday and Wednesday of next week at 8.04 ft and 8.06 ft, respectively. 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. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... Frost Advisory from 8 PM this evening to 10 AM PDT Sunday for CAZ110-111-114-120.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 5 PM PDT this afternoon for PZZ450.

Small Craft Advisory until 10 PM PDT this evening for PZZ470.

Small Craft Advisory until 4 AM PDT Sunday for PZZ475.