Point St. George to Cape Mendocino CA from 10 to 60 NM Marine Forecast
|Today...N Winds 15 To 25 Kt. Waves N 10 Ft At 9 Seconds...And W 5 Ft At 13 Seconds. Patchy Fog.|
|Tonight...N Winds 15 To 25 Kt. Waves N 10 Ft At 9 Seconds... And W 4 Ft At 12 Seconds.|
|Fri...Nw Winds 5 To 15 Kt. Waves N 8 Ft At 8 Seconds.|
|Fri Night...N Winds 5 To 10 Kt. Waves N 6 Ft At 7 Seconds.|
|Sat...N Winds 5 To 15 Kt. Waves N 5 Ft At 6 Seconds...And W 5 Ft At 18 Seconds.|
|Sun...S Winds 5 To 15 Kt. Waves W 6 Ft At 13 Seconds.|
|Mon...Sw Winds 5 To 15 Kt. Waves W 8 Ft At 12 Seconds...And S 2 Ft At 18 Seconds.|
| Area Forecast Discussion|
National Weather Service Eureka CA
244pm PDT Wednesday September 22 2021
Seasonable temperatures arrived with the passing of an upper trough. Offshore flow will develop tonight and tomorrow night. Temperatures will warm through the end of the week as the North Pacific High noses in from the southwest. No precipitation is expected through the weekend while the ridge flattens and temperatures moderate back down.
Some morning shallow fog clung along the immediate coast today, eventually splashing in and out of the coast with the northwest winds before peeling down from the north. An upper trough passed by today and allowed the high temperatures to drop significantly along the coast, upwards of 20 degrees from what was observed yesterday. Offshore winds will develop overnight, creating some brief fire concerns. See the fire discussion below. The North Pacific High will quickly begin nosing in overnight behind the trough. Temperatures will warm in response, though coastal temperatures will be moderated by the westerly flow and perhaps some coastal stratus. Winds will be lighter Friday and may have a better chance of warming at the coast if the stratus drys out.
The weekend will feature continued dry and quiet weather, while the upper ridge 'flattens' and begins to give way to some gradual cooling heading into next week. There continues to be signs in the ensemble and deterministic guidance of some rain arriving as early as Monday, or possibly Tuesday. Ensemble guidance is homing in on some solid chances for at least a wetting rain for that time. Probabilities increase northward for areas starting from Cape Mendocino. There are probabilities for more, but still some spotty individual members in there, especially GFS. There are hints this could mark a pattern change more favorable for at least some more general 'troughiness'.
Northerlies are expected to increase and reach small craft advisory (21-25kt) this afternoon/early evening across mainly the outer waters and near prominent headlands. Northerlies will persist through the day on Thu, then ease on Friday. Southerlies should also develop for the inner waters on Friday as steep short period northerly waves slowly diminish. A series of small (6ft or less) mid-period NW swells are forecast to spread into the waters through the forecast period as well. Long-range models hint at a trough deepening over the NEPAC early next week, possibly sending us a larger NW swell around Tue-Wednesday next week.
RH recoveries have improved after an onshore flow push as an upper level trough passed through. Westerly up-valley winds picked up this afternoon. Drying northeast winds will pick up overnight. Winds will gust to around 20 to very isolated 30 mph over the ridges. The southern zones of 264 and 277 are currently headlined for the resulting low RH values and locally critical fire weather conditions. These winds will ease heading into Thursday night and Friday. Dry weather will continue through the weekend, but with a gradual cooling trend and improved RH recoveries.
.EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3am PDT Friday for PZZ470-475.