906 FXUS66 KEKA 101122 CCA AFDEKA AREA FORECAST DISCUSSION...CORRECTED National Weather Service Eureka CA 422 AM PDT Wed Oct 10 2018 .SYNOPSIS...A weak weather system will bring slightly cooler temperatures today and Thursday along with some coastal stratus. High pressure and offshore flow builds in Friday bringing clear skies. High pressure will continue to bring warm and dry weather into the middle of next week, although the coast may see a return of stratus and fog. && .DISCUSSION...High pressure is in place over the eastern Pacific with a trough over the intermountain west. Several shortwaves moving down into the trough will impact our weather over the next several days. Slightly cooler temperatures are expected over the inland areas today and Thursday. This morning there is some stratus in the near coastal river valleys, but this should burn off fairly quickly. Tonight with the approaching shortwave stratus and drizzle is expected along the much of the coast. As this trough moves south offshore flow sets up and this should keep the Del Norte and northern Humboldt coasts mostly clear. Farther inland cooler and drier air is expected to move and frost is likely in some of the colder valleys in Trinity county. So have issued a frost advisory for late tonight. Thursday night into Friday the high pressure noses its way into the Pacific Northwest creating northeast to east offshore flow across NW California. This should keep skies fairly clear across the area. Frost is likely once again across Trinity county. It is also possible in the interior valleys of Humboldt, Del Norte and northern Mendocino counties but confidence is low on this and it will need to be watched. For the weekend inland temperatures will continue to warm back into the mid to upper 80s. Winds will weaken considerable at the coast. It looks like stratus will come back to the Mendocino coast on Friday night into Saturday morning. Saturday night the winds continues to weak and stratus will likely spread across much of the coast. It may be a shallow layer and confined to the immediate coast. The first half of next weeks look to continue to have high pressure and dry conditions over the area. The weak winds will likely allow a shallow layer of stratus to linger in the coastal areas. MKK && .AVIATION...An easterly component to the light winds this morning has helped keep low clouds and fog at bay along the coast. Some low stratus and fog has been occurring along the coastal interior drainages and may maintain some mvfr conditions through the mid morning hours. Thus some local mvfr to ifr conditions are still possible through 15Z but should give way to VFR for the remainder of the TAF cycle as the offshore flow should be a little stronger tonight. && .MARINE...A strong expansive area of surface high pressure will continue over the northeastern Pacific while low pressure was persists across the Great Basin. The result is a tight pressure gradient exists between these two features that is very gradually decreasing. The resulting wind field is also diminishing in speed and by late this morning, the gale force wind gusts should cease. Gusty north winds will still prevail however through Friday but should remain within the sca criteria. The wind speeds will fall off drastically by the weekend as low pressure develops offshore over central/northern California. Wave wise, a mid period northwesterly swell will continue to spread across the coastal waters during the next seven days...ranging from 4 to 6 feet at 12 seconds today, then subsiding to 3 feet at 10 seconds Thursday and Friday, followed by a potential increase from 4 to 7 feet at 9 seconds this Sunday. In addition, a southerly swell from 3 to 5 feet at 14 seconds appears to be on track tonight through the weekend. && .EKA WATCHES/WARNINGS/ADVISORIES... CA...Frost Advisory from 2 AM to 9 AM PDT Thursday for CAZ107-108. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 PM PDT this evening for PZZ450-455. Small Craft Advisory until 3 PM PDT Thursday for PZZ470. Gale Warning until 11 AM PDT this morning for PZZ475. && $$ Visit us at http://www.weather.gov/eureka Follow us on Facebook and Twitter at: http://www.facebook.com/NWSEureka http://www.twitter.com/nwseureka For forecast zone information see the forecast zone map online: http://www.weather.gov/eureka/zonemap.png