textproduct: Eureka

SYNOPSIS

High pressure continues to build into the area with hot temperatures expected into early next week. The near coastal and coastal areas may start to see more marine influence over the weekend and into early next week while Trinity county is expected to see the hottest temperatures Monday and Tuesday. Cooler temperatures are possible starting on Wednesday.

DISCUSSION

High pressure continues to build in across the area and the interior is expected to see a few hot days of this heatwave. A southerly surge of clouds could make its way up to Ukiah but the likelihood of that depends on available moisture at low levels and advected stratus into the Russian River Valley and Anderson Valley. This will likely start to cool temperatures at the immediate coast and inland to areas as far as Boonville or so. Overnight lows will likely drop into the 50s in most of the valleys, however the ridges are expected to stay much warmer, likely in the 70s. This will increase the heat risk in these areas.

For the weekend a weak upper level trough is expected to drop down from the north. This is expected to bring some instability, but current moisture profiles look like they remain too dry for any thunderstorms. Temperatures are expected to remain more steady fluctuating somewhere around 100 in the afternoons. The winds southerly winds along the Mendocino coast are expected to slightly increase and keep the stratus in place. The high pressure is expected to keep the marine layer fairly shallow and it may mix out each afternoon. Sunday it looks fairly certain that the marine layer will be well north of Cape Mendocino as the winds get lighter. Monday and Tuesday high pressure continues to the strengthen over the area and is expected to some of the hottest temperatures of this heat wave to Trinity county. Areas closer to the coast there is more uncertainty and this will need to be monitored as it gets closer.

Wednesday the high pressure is expected to start to break down and cooler temperatures are expected aloft. This will cool temperatures across the area and likely deepen the marine layer. MKK

AVIATION

VFR conditions prevail at the coastal terminals overnight with minimal cloud cover as offshore wind continues. Southeasterly winds have become the dominant regime as the high pressure dome expands off the coast of the PACNW. Diurnal patterns will continue with wind gusts returning Friday afternoon, at a lighter clip than previous days. Models hint at a few hours of reduced visibility around 12z or so at KCEC and KACV. The southerly push overnight could push light fog or stratus up the valley towards KUKI but moisture is lacking with the dry easterly winds as a source. /EYS

MARINE

Gale strength northerlies persist through the outer zones through Saturday. The southern outer zone will have less coverage Friday, mainly around Cape Mendocino and westward. Northerly winds and steep seas will continue advisory conditions for the inner zones. Strengthening northerlies over the northern outer waters Friday will build steep and hazardous seas up to 14 ft. The northern inner waters will have to be watched for a brief surge of hazardous seas late Friday. Currently it looks like the gales will continue beyond 10 to 20 nm north of Cape Mendocino on Saturday, then start to diminish on Sunday and this allows a southerly surge to move northward. Winds are generally expected to remain lighter into early next week.

FIRE WEATHER

Temperatures are expected to remain hot and dry into early next. Over the weekend a shortwave moving down form the Pacific Northwest is expected to increase instability and this may lead to increased mixing heights. It doesn't look like there will be enough moisture in NW California for any thunderstorms, that is expected to remain well east and south of the area. Early next week temperatures may climb slightly more and the hottest temperatures of the heat wave are expected. Wednesday into late in the week cooler temperatures are expected. This may also bring stronger winds or possibly thunderstorms depending on how the pattern evolves. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... Heat Advisory until 10 PM PDT Friday for CAZ113-114-118>120.

NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 5 PM PDT Friday for PZZ450.

Small Craft Advisory until 9 AM PDT Friday for PZZ455.

Gale Warning until 9 PM PDT Saturday for PZZ470.

Gale Warning until 9 AM PDT Friday for PZZ475.