textproduct: Eureka

KEY MESSAGES

* Dry and unseasonably warm weather forecast through midday on Thursday.

* Moderate to heavy rain and gusty south winds across much of the area throughout Friday.

* Very large surf Saturday with breaking waves over 25 feet is possible. This will increase beach erosion and possibly bring some coastal flooding.

* Additional rain and wind possible over the weekend and into early next week.

SYNOPSIS

Unseasonably warm and dry weather is expected today and Thursday. Friday a strong cold front is expected to bring gusty winds and moderate to heavy rain to the area. There may be a brief break in the rain on Saturday before another system brings more rain and wind Saturday night and Sunday.

DISCUSSION

High pressure to the east and a trough to the west are bringing southerly winds and warm temperatures to the area. Today will likely be the warmest day for a while in many areas. Highs may reach close to 80 in the southern areas. Tonight into Thursday morning a weak front approaches the area. Some of the models show this bringing some light showers or sprinkles to the coastal areas while others keep it dry. So the forecast has a slight chance of rain near the coast. If any does fall it should be light. Much of the area is expected to continue to warm conditions although there is a bit more uncertainty on the temperatures.

Thursday night the winds are expected to increase across the area as the front approaches the area. The stronger winds are expected in Del Norte county and the ridges and the King Range Humboldt county. The GFS and the RRFS both show 55 to 65 kt at 925 and 850 MB as the front moves into Humboldt and Del Norte county. So have issued a wind advisory for the Del Norte county as well as the higher terrain of Humboldt county. This may need to be expanded or upgraded. One question is how unstable the low levels will and if the winds will be able to mix down to the lower elevations, especially along the coast. The winds will likely be strongest just ahead of the heavier rain. The NBM and the GFS show some light rain start late Thursday or Thursday night. If there is any rain it will likely be on the upslope areas such as the south slopes of the King Range. The front is expected to bring the heavier rain starting around sunrise and rapidly spreading across the rest of the area by mid-morning.

The heavier rain is expected to start around sunrise on Friday morning. The front is expected to move through during the day. A quick 1 to 3 inches is expected with the front. The NBM is showing a 70 to 95 percent chance of over 2 inches in Del Norte, Humboldt and northern Mendocino counties. There is even a 60 percent of over two inches in northern Lake county. Farther south and in the Hayfork/Weaverville areas of Trinity county probabilities are less than 50 percent. It looks like the burn scars will not reach the flooding thresholds, but this will need to be monitored as it gets closer and comes more within range of the higher resolution models.

Behind the front showers are expected, especially in Humboldt, Del Norte and northern Mendocino counties. The heavier showers may bring close to an additional inch of rain with them. There is the potential for some thunder with these showers as well The NBM thunder probabilities have come down slightly, but are still around 15 to 20 percent.

Generally dry weather is expected on Saturday, although there may be some lingering showers. This will be short-lived however with the next weather system moving in Saturday night or Sunday. This one is expected to have lighter winds and rain, but still could see a half inch in Lake county to nearly two inches in the mountains of Humboldt and Del Norte counties. Drier weather is possible Monday and part of Tuesday with another system possible later on Tuesday. MKK

AVIATION

High pressure is bringing VFR conditions to many areas this morning. There is some stratus in the valleys of Humboldt and Del Norte counties. These are generally bringing MVFR conditions. South to southeast winds are in place and helping to keep the coastal ceilings up. Skies are expected to scatter out fairly quickly this morning with southerly winds picking up some. Tonight stratus is expected to return in the coastal areas once again. This may bring some MVFR or IFR conditions back to the coast at some point tonight. MKK

MARINE

Southerly winds continue across the waters this morning, but remain only around 10 to 20 kt. A northwest swell of 8 to 11 feet at 13 seconds continues to move through as well. The southerly winds are expected to increase slightly this afternoon, but generally remain around 5 to 15 kt in the southern waters and 15 to 20 kt in the northern waters through tonight. Thursday a weak front is approaching the area and is expected to 20 to 25 kt southerly winds to most of the area. A new northwest swell is expected to move in building waves slightly to 13 to 14 feet at 15 seconds.

A strong front is expected to rapidly increase winds across the area Thursday night and Friday. Gales are expected to start near or shortly before midnight in the northern waters and may expand into the southern waters towards morning. There is the potential for storm force wind gusts if the comes in on the stronger side of model guidance and this will need to be watched as it gets into range of the high resolution models. Just as these strong winds are diminishing on Friday afternoon a very large swell is expected. The wave model shows this building to around 25 feet at 18 seconds. This could lead to breakers around 30t. A high surf warning will likely be needed as this gets closer. Saturday night into Sunday another system is expected to bring gales or near gales. MKK

COASTAL FLOODING

Water levels inside Humboldt Bay continue to run 1.2 to 1.5 feet over the astronomical tides. Winds will continue to be southerly which tends to increase water levels slightly. The max high tide is expected to drop each day through the weekend, yet increasingly stronger southerly winds are likely to offset at least some of this decrease in max tide height. The water levels are expected to be slightly below 8.8 feet the next couple of days around high tide (11/11 @12:06pm, 11/12 @12:55pm).

EKA WATCHES/WARNINGS/ADVISORIES

CA... Wind Advisory from midnight Thursday night to 1 PM PST Friday for CAZ101-102-104>106.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until midnight PST Thursday night for PZZ450.

Gale Watch from late Thursday night through Friday afternoon for PZZ450.

Small Craft Advisory until 10 AM PST Wednesday for PZZ455.

Small Craft Advisory until 10 PM PST Thursday for PZZ470.

Gale Watch from Thursday evening through Friday afternoon for PZZ470.

Small Craft Advisory until 3 AM PST Friday for PZZ475.