Cape Mendocino to Point Arena CA from 10 NM to 60 NM Marine Forecast
|Today...Nw Winds 10 To 20 Kt. Waves Nw 8 Ft At 11 Seconds...And S 2 Ft At 14 Seconds. A Slight Chance Of Showers.|
|Tonight...N Winds 15 To 25 Kt. Waves Nw 11 Ft At 12 Seconds.|
|Mon...N Winds 25 Kt. Waves N 13 Ft At 9 Seconds...And S 2 Ft At 15 Seconds.|
|Mon Night...N Winds 10 To 20 Kt. Waves N 12 Ft At 9 Seconds.|
|Tue...Nw Winds 5 To 10 Kt. Waves Nw 7 Ft At 11 Seconds.|
|Wed...N Winds 15 To 25 Kt. Waves N 8 Ft At 7 Seconds...And Nw 6 Ft At 15 Seconds.|
|Thu...N Winds 15 To 25 Kt. Waves N 10 Ft At 9 Seconds...And Nw 5 Ft At 13 Seconds.|
| Area Forecast Discussion|
National Weather Service Eureka CA
544am PDT Sunday September 19 2021
Expect areas of showers across northwest California diminish this morning, followed by clearing skies with a relatively cool and breezy afternoon. More dry weather is on tap for the week ahead, with warming temperatures even at the coast early in the week thanks to offshore flow.
The upper level trough and a renewed cold front moved into northern California early this morning. Radar returns have been increasing in coverage and intensity for the northern portion of the region, particularly for Del Norte and Humboldt counties. Otherwise, band of showers will continue to drop southeast into Mendocino County. Rainfall amounts from a few hundreds to four tenth of an inch per hour range. The high resolution models indicates that the showers activity will gradually diminish through the morning hours across northwest California.
The aforementioned upper level trough will continue to eject eastward away from the west coast today, and as a result moisture content is expected to decrease in the area. The winds will begin to shift to the west-northwest. A high pressure ridge builds to our north and east over the Great Basin tonight. This will promote dry offshore winds tonight through Tuesday, especially over the interior ridges on Monday. While some cool marine layer stratus will try to linger Sunday night along the coast, increasingly dry air will probably erode any lingering cloud cover heading into Monday, with sunny skies for much of the area through Tuesday or Wednesday. That evolution will favor increasing afternoon high temperatures through Tuesday, with inland values in the 90s probable during Tuesday. Even coastal areas may see some highs in the 70s on Monday or Tuesday if the offshore winds stay at bay.
Winds will become northerly today and increase in speed tonight. Breezy northerly winds will continue Monday, but diminish Monday night and Tuesday. Small Craft Advisories have been hoisted for all marine zones (albeit with different start and end times). A mid-period NW swell will build into the area today and continue through mid-week. /SEC
Another round of showers associated with the strong upper level trough were moving across the region this morning. The bulk of the rainfall was farther to the north, reaching portions of Mendocino County but amounts much less than areas farther north and any drops southern into Lake County. Offshore component is expected to develop as high pressure builds quickly in to the north tonight into Monday, especially over exposed higher slopes and ridges. This wind will bring in much drier air, followed by a hotter and drier day on Monday. Some locally breezy conditions may persist over the exposed ridgetops Monday night, but expect winds will be lighter overall. However, humidity recoveries heading into Tuesday morning will be much poorer. That means the fire weather watch remains on track, but it is possible in may need to be extended into a portion of Monday night. Do not think fuels will dry enough over zones to the north and west to support any red flag conditions with this offshore flow event, however just the winds and the humidity may get there locally over some of the highest ridges in zones 212 and 277, and maybe even locally elsewhere Monday and Monday night as we dry out. Winds will ease additionally mid-week, but it will remain warm and dry across the interior. /AAD
.EKA WATCHES/WARNINGS/ADVISORIES... CA... Fire Weather Watch from this evening through Monday afternoon for Lake County Portion of Lake/Napa/Sonoma RU.
NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from noon Monday to midnight PDT Monday night for Pt St George to Cape Mendocino out 10 nm.
Small Craft Advisory from 6pm this evening to 9pm PDT Monday for Cape Mendocino to Pt Arena out 10 nm.
Small Craft Advisory from 3am Monday to 6am PDT Tuesday for Pt St George to Cape Mendocino 10 to 60 nm.
Small Craft Advisory from 6pm this evening to 6am PDT Tuesday for Cape Mendocino to Pt Arena 10 to 60 nm.