textproduct: Eureka

SYNOPSIS

Cooler inland temperatures will bottom out today as an upper level low moves onshore in the Pacific Northwest. The low will also bring some breezy winds to the interior. Above normal temperatures are expected to return for the weekend with another chance for thunderstorms next week.

DISCUSSION

The upper level low moves onshore at the Pacific northwest. Cooler weather continues to occur through today with continued breezy conditions this afternoon and diminishing into this evening. The lower heights and cooler temperatures aloft have weakened the marine inversion which has allowed the coast to mostly clear out this afternoon. Into tomorrow the upper level low is forecast to make its way northeast into British Columbia which will enable temperatures to warm some for the interior. The warming temperatures aloft will likely make stratus more prevalent through the weekend. The flow is expected to be fairly light, although the 700 mb winds are generally out of the south and this should keep smoke to the north and east of the area unless a new fire develops to the south.

For the weekend high pressure strengthens and edges slightly to the west. This is expected to bring warmer temperatures to the inland areas. Highs are expected to be back in the mid 90s to around 100 in the warmer valleys. This will bring more minor to locally moderate heat risk.

Starting Monday, monsoonal moisture is anticipated to make it's way north and west into the area. At this point there doesn't appear to be a trigger to get any thunderstorms going and instability is fairly limited on Monday and Tuesday. For now it looks like Wednesday has the best chance to see some thunderstorms in Trinity county. However it would only take a small shift in the timing of a shortwave or increased instability to have some more thunderstorms. This will need to be monitored closely.

AVIATION

Typical gusty afternoon winds from the northwest are forecast along the coast. Ukiah is expected to see some stronger afternoon winds once again. Tonight the clouds are expected to return again, but it may take until around or after 06Z. The CIGs may not be all that low, possibly just MVFR with periods of IFR. Cloud cover may be more persistent for coastal terminals tomorrow, especially around Humboldt Bay.

MARINE

Northerly winds are expected to increase over the next 12 hours then remain fairly consistent at small craft conditions through the weekend. Winds will remain higher in the southern waters with near gale gusts in the lee of Cape Mendocino late this afternoon and into very early tomorrow morning. In general, winds should start to diminish, slightly at first, but more so on Sunday. Winds are expected at only around 10 kt Monday and Tuesday before starting to increase again late in the week.

A larger southerly swell is starting to show up in the models. This is from tropical storm Elida off the Mexico coast. The current wave model shows these building to around 4 feet at 14 seconds on Monday. This could create some larger breakers than usual on the southern facing beaches, especially south of Cape Mendocino. MKK

FIRE WEATHER

Stronger northwest winds are expected this afternoon/evening in Mendocino, Lake, and eastern Trinity counties. Afternoon RH is expected to not be as low as on Wednesday. Lake and Eastern Trinity county may still see some areas in the teens, however most other areas are expected to be in the 20s or higher. Winds ease Friday, back to more typical afternoon breezes, but afternoon RH will also lower back into the teens and 20s. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT Saturday for PZZ455-475.

Small Craft Advisory from 11 PM this evening to 9 AM PDT Saturday for PZZ470.