Sunrise 6:22 AM   Sunset 7:59 PM Moonrise 7:09 PM   Moonset 5:11 AM

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PZZ455 Cape Mendocino To Pt Arena Out 10 Nm- 846 Am Pdt Tue Apr 23 2024
Today - S winds 5 to 10 kt. Waves N 6 ft at 8 seconds - .and S 2 ft at 16 seconds. Tonight - N winds 5 kt. Waves nw 5 ft at 10 seconds - .and S 2 ft at 15 seconds. Wed - NW winds 5 to 10 kt. Waves nw 3 ft at 9 seconds - .and S 2 ft at 15 seconds. Wed night - NW winds 5 to 15 kt. Waves N 5 ft at 5 seconds - .and S 2 ft at 16 seconds. Thu - W winds 5 to 10 kt. Waves nw 5 ft at 5 seconds - .and S 2 ft at 15 seconds. Fri - NW winds 10 to 15 kt. Waves W 7 ft at 9 seconds. Sat - W winds 10 kt. Waves nw 5 ft at 7 seconds - .and nw 4 ft at 15 seconds.

PZZ400 846 Am Pdt Tue Apr 23 2024
Synopsis for northern california waters - Current southerly winds right along shore and northerly winds in the outer waters will gradually weaken through day as a cut-off low pressure system south of the area continues to moves west. Gentle winds will more turn more northerly and onshore this evening. These calmer winds will lead to short period seas dropping below 6 feet through early Wednesday morning. Calmer conditions will persist with only minor and isolated enhancement of northerlies around cape mendocino through Thursday.

FXUS66 KEKA 231115 AFDEKA

AREA FORECAST DISCUSSION National Weather Service Eureka CA 415 AM PDT Tue Apr 23 2024

SYNOPSIS
Showers and thunderstorms are forecast for the interior this afternoon, mainly in Trinity county. A cooling trend will start today with additional cooling Wednesday.
Drastically cooler interior temperatures, rain and high mountain snow will return Thursday through Friday. Additional showers and below normal temperatures are expected through the weekend.

DISCUSSION
A shortwave moving into the Pacific Northwest will bring cooler temperatures aloft. Farther south off the southern CA coast an upper level low is bringing southerly flow. This is bringing some mid-level moisture to the area and this will combine with the cooler air aloft to generate some instability.
This morning there is some weak elevated instability bringing a few showers and even a few flashes of lightning to the Humboldt county coastal areas. The bigger threat for thunderstorms will be this afternoon in mainly Trinity county, but may also extend south into northeastern Mendocino county. At this point it looks like it will remain north of Lake county. The hires models are showing around 100 to 300 j/kg of CAPE. This should be enough to generate some showers and thunderstorms this afternoon and evening. Lapse rates aloft diminish through the afternoon to only around 6c/km and this may end convection by late afternoon.

Along the coast the ACV profiler is showers the marine layer rapidly building and is already around 2,000 feet deep at 2AM. The satellite shows this cloud cover spreading north along the coast and then into the river valleys. The immediate coast is unlikely to see too much sun this afternoon and therefore will keep temperatures notably cooler.

Tuesday night is expected to be dry once the showers come to an end, although drizzle may form along the coast. Wednesday widespread coastal stratus is expected in the morning and may take some time to clear back to near the coast. Inland a few showers are possible again, but the threat for thunder looks lower than Tuesday. The flow aloft will be out of the west which is not a favorable pattern for convection. Wednesday night is expected to be mainly dry.

Thursday an upper level trough is expected to drop down from the northwest bringing cooler air and some rain to the area. At this point it looks like the rain will be starting in Humboldt and Del Norte counties and is expected to spread south and east in the afternoon. The front is expected to dissipate as it moves south with southern Mendocino and Lake counties receiving very little rain.

Friday and into the weekend the pattern remains cool and moist with zonal onshore flow through the column. Shortwaves are expected to move through this and this will bring some local some periods of light precipitation. Overall amounts are expected to be light and snow levels will generally be above 4000 to 5000 feet. Inland valley temperatures will likely see high temperatures struggle to get out of the 50s on Friday with only some slight warming going into the weekend. MKK

AVIATION
A complex aviation environment has built in overnight.
A southerly jet under the cover of a strong marine inversion near shore has pulled a deck of marine stratus north all along the coast.
That said, the southerly wind is so strong that appears to be disrupting the marine layer leading to waves and breaks in the cloud deck on satellite, especially north of Cape Mendocino. This set up has lead to only inconsistent IFR conditions that will most likely continue through the morning.

Though daytime sun will fight to mix out the clouds, weakening winds turning onshore will actually enhance the ceilings by late afternoon, at least offshore. Models place a 30 to 60% chance of IFR ceilings along parts of the coast with most of the uncertainty likely from the location of the stratus hanging right along shore.
Regardless of the efficacy of clearing this afternoon, coastal stratus and fog are most likely to quickly rebound onshore late this evening bringing widespread and more consistent IFR conditions to coastal terminals.

For the interior, southerly wind has brought widespread fog up the Russian River Valley with clearer VFR conditions further north. Ukiah should expected IFR to LIFR ceilings this morning before quickly clearing by late morning. Weakening southerly wind is unlikely (10 to 20% chance) to bring a repeat of fog early Wednesday morning. /JHW

MARINE
For the most part, northerly winds have gradually decreased this evening with gusts below 20kts everywhere except the for northwest outer waters. That said, stable air combined with interactions with a cutoff low pressure system off the Sonoma County Coast have actually generated and unusually strong southerly jet alongshore. Southerly gusts up to 30 mph have been locally observed near Pt. Arena and Crescent City this morning. These battling winds have generated a complex short period wave environment with combined heights of 5 to 10 feet.

Winds will continue to weaken and more consistently turn northerly and onshore later Tuesday evening through late weak. A series of passing fronts will lightly enhance winds, though gusts looks moderate at best with 20 kt gusts restricted right around Cape Mendocino. Such winds will most likely not even be strong enough to even build short period seas to 6 feet.

Through short period seas will dominate the sea state through the week, a series of persistent, mid period northwest swells up to 5 feet will generally compliment the northerly wind waves. /JHW

EKA WATCHES/WARNINGS/ADVISORIES
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 AM PDT this morning for PZZ470.

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Fort Bragg Landing
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Tue -- 05:43 AM PDT     0.03 feet Low Tide
Tue -- 06:11 AM PDT     Moonset
Tue -- 06:25 AM PDT     Sunrise
Tue -- 12:12 PM PDT     4.39 feet High Tide
Tue -- 04:51 PM PDT     Full Moon
Tue -- 05:25 PM PDT     1.91 feet Low Tide
Tue -- 08:01 PM PDT     Sunset
Tue -- 08:09 PM PDT     Moonrise
Tue -- 11:33 PM PDT     5.62 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Fort Bragg Landing, California, Tide feet

Point Cabrillo
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Tue -- 02:49 AM PDT     -1.28 knots Max Ebb
Tue -- 06:11 AM PDT     Moonset
Tue -- 06:26 AM PDT     Sunrise
Tue -- 06:35 AM PDT     0.00 knots Slack
Tue -- 09:32 AM PDT     1.03 knots Max Flood
Tue -- 12:47 PM PDT     -0.00 knots Slack
Tue -- 03:13 PM PDT     -0.84 knots Max Ebb
Tue -- 04:51 PM PDT     Full Moon
Tue -- 06:31 PM PDT     0.00 knots Slack
Tue -- 08:01 PM PDT     Sunset
Tue -- 08:09 PM PDT     Moonrise
Tue -- 09:20 PM PDT     0.82 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION

Point Cabrillo, California Current, knots

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