textproduct: Eureka

KEY MESSAGES

* Another round of light to locally moderate rain likely today.

* Warmer temperatures and mostly dry weather likely Wednesday through the end of the week and into the weekend.

* Stronger storms with heavy rain possible starting around November 10th.

SYNOPSIS

Another round of rainfall is expected today. Warmer and mostly dry weather is likely Wednesday and through the weekend. Chances for heavy rain, strong wind, and heavy mountain snow arrives early to mid next week.

DISCUSSION

An approaching low pressure system will bring mostly light to locally moderate rainfall to the area. The main frontal passage will move through in the morning bringing widespread light rain. Post-frontal showers around the low pressure system are likely to bring additional light to locally moderate rain showers into the late morning and early afternoon, primarily to Mendocino and Lake Counties. A few thunderstorms and heavier downpours are possible with this batch of rain. Rainfall totals are expected to be about a tenth to a half inch of rain from about Eureka and southward. There remains a 30% chance for the Humboldt Coast to see no rain and a 60% chance for the Del Norte Coast. Conversely, there is around a 20-30% chance for areas of Southern Mendocino and southern Lake Counties could see over an inch of rain. This scenario would require heavier showers with embedded thunderstorms to develop in the afternoon.

Along with the rainfall, breezy southeast winds are likely ahead of the front along the coast and on exposed ridges. Gusts peak at around 20 to 30 mph with locally higher gusts possible on the ridges of the King Range. Southeast flow and downsloping often brings warmer temperatures along the coast (and lower than expected rainfall amounts). This may bring mid to high 60s to some areas around Humboldt Bay. Interior areas remain in the 50s to low 60s.

Another weaker front moves north of the area Wednesday. Some light rain showers is possible with this Wednesday evening and night, with the best chances (60%) for any measurable rain in Del Norte which declines sharply to 20% along the Humboldt Coast. There is around a 20% chance for over a quarter inch in Del Norte. Otherwise, high pressure builds in over the area, allowing for warmer temperatures late week and through the weekend.

Attention remains focused on the extended forecast when models and ensemble clusters are coming into closer agreement on a shift to a more active weather pattern. The threat starts after the 9th, likely near of after the 10th. For that period, there is a 40 to 60% chance of exceeding two inches of rain over a two day period, and a 30 to 50% chance of exceeding three inches, respectively. Cluster analysis shows 50% of the members with over 2 inches in a 24 hour period. The possible atmospheric river storm system would be capable of strong southerly winds as well. JB/JJW

AVIATION...(6Z TAFs)

An approaching frontal system will bring rain with lowering ceilings. Ceilings are likely to remain VFR along the Humboldt and Del Norte coasts as southeast flow keeps ceilings elevated. Some brief MVFR visibilities and ceilings are possible during heavier showers. Moderate rainfall towards Mendocino and Lake Counties is likely to bring MVFR ceilings to UKI. Potentially heavier showers in the afternoon may support IFR to MVFR ceilings and visibilities. Conditions improve in the evening and overnight as the front moves out of the area. Persistent offshore flow is likely to prevent a widespread marine layer from forming in the evening, however areas of patchy fog is possible. JB

MARINE

An approaching low pressure system will approach the area early this morning, increasing southerly winds. Sustained 20 to 25 kt winds are likely as the front passes starting from the south and west and moving north and east. Localized and brief near-gale force gusts are possible as the front passes, mainly before 3AM and 9AM. A few thunderstorms are possible south of Cape Mendocino this afternoon which may have locally stronger winds nearing gale force. Seas remain elevated as a long period NW swell of 7 to 8 ft continues to build and combine with short period wind waves of 6 to 8 ft. Combined seas may reach 11 to 13 ft this afternoon and evening. Winds quickly ease Wednesday, however seas will remain elevated as long period NW swells will continue through the week. Winds turn northerly Thursday and moderate winds are likely in the lee of Cape Mendocino through Saturday. JB

BEACH HAZARDS

A very long period northwest swell peaked Monday afternoon, but the size and energy will be very slow to subside. This continues to bring an extreme threat for sneaker waves through this morning as winds remain light and other wave groups remain limited. A Beach Hazard Statement is in effect through this morning for this sneaker wave threat.

Sneaker waves are relatively large, unexpected waves with long period between large sets. Up to 30 minutes may pass between waves. Large, unexpected waves can sweep across the beach without warning, sweeping people into the sea from rocks, jetties, and beaches. Avoid jetties, steep beaches, and stay much farther back from the ocean!

EKA WATCHES/WARNINGS/ADVISORIES

CA... Beach Hazards Statement until 9 AM PST this morning for CAZ101-103-104-109.

Frost Advisory until 9 AM PST this morning for CAZ110-111- 114.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 PM PST this evening for PZZ450- 455.

Small Craft Advisory until 3 AM PST Wednesday for PZZ470.

Small Craft Advisory until 3 AM PST Wednesday for PZZ475.