Marine Weather and Tide Forecast for Weaverville, CA

DISCUSSION
Pocket of shallow fog, some dense quickly eroded through the morning hours; however, a return fog is underway along the coast. Dense fog visibilities are already being observed along the North Coast, and an Advisory may be required later if coverage and consistency increase. Light showers to light drizzle can be expected to continue along the North Coast, mainly in Del Norte.
Latest guidance only yields trace amounts of measurable rainfall for Del Norte, but persistent light drizzle may accumulate a few hundredths along portions of the North Coast. It will remain dry elsewhere with increasing high temperatures.

The persistent ridge of high pressure southwest of the region responsible for blocking Pacific storm systems will strengthen and nose eastward through the workweek. Significant warming will occur as a result. The current forecast yields high temperatures in the interior reaching 10 to 15 to locally up to 20 degrees above climatological norms mid to late this week and into the weekend. NBM shows a high probability (70 to 80%) for the warmer interior valleys to exceed 70 F Thursday and especially Friday (80 to 90%). When looking at NBM probabilities for exceeding 75F, the Ukiah area shows probabilities of 50% for Thursday and Friday. This would likely break the high temperature record of 72F from 1958 for Ukiah on Friday if the forecast holds.

Ensembles and clusters show an attempt to weaken the formidable ridge through the weekend. Precipitation chances start to increase through the latter portion of the weekend, but meaningful breakdown of the ridge or zonal flow may not occur into early next week when rain chances look to further increase. JJW



AVIATION
(18Z TAFs)...VFR conditions have returned to all terminals late this morning and early this afternoon. A shift to northwesterly winds is likely to bring offshore stratus back to the coastal terminals, returning LIFR conditions. Model guidance suggests ceilings lifting or potentially scattering overnight as the marine layer deepens. Moist surface conditions could promote areas of patchy ground fog, however, especially in the interior valleys.
Fog is possible again in the interior valleys tonight, including UKI. Any fog is likely to lift and scatter shortly after sunrise. JB



MARINE
Generally light winds are forecast through Tuesday morning, with south winds forecast north of Cape Mendocino and west- northwest winds forecast south of the Cape. Another mid-period northwest swell will fill in this afternoon and evening, peaking at 7-9 ft at 13 seconds overnight into Tuesday. Combined seas may briefly exceed 10 ft in some areas. Northerly winds are also likely to trend northward Tuesday and Wednesday. Northerly wind gusts of 15- 25 kts are possible south of Cape Mendocino Tuesday and Wednesday afternoons and steep wind waves of 5-7 ft are possible. Additional mid-period northwest swells will continue to fill in through the week, keeping seas elevated. JB



BEACH HAZARDS
A low to moderate threat of sneaker waves is expected for the Del Norte, Humboldt, and Mendocino coastlines late this week. A mid-period westerly swell generated by a storm currently ~500mi south of the Aleutian Islands will enter the coastal waters early Thursday morning. A lack of local wind waves will allow this swell to dominate the sea state, creating beach conditions that could look deceivingly calm. Forecast confidence will grow in time as NDBC data becomes available for observations closer to NW CA as the swell passes midweek. Remember to never turn your back to the ocean, and to avoid steep beaches, jetties, outcroppings, and rocks during these events. DS



EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
None.