textproduct: Eureka

SYNOPSIS

Temperatures will slowly continue to warm and are expected to peak on Monday. Gloomy stratus will continue to blanket the coast again Sunday with a better chance for clearing Monday. There is the possibility of some rain, drizzle, and inland thunderstorms on Wednesday or Thursday.

DISCUSSION

The axis of the upper level ridges remains to the east of the area. The winds are keeping the marine layer clouds in place along the coast. Inland areas remain warm with highs in the 80s to near 90. The marine layer is keeping the western half of the coastal counties cooler. This slightly moderated air is impacting Gasquet, Hoopa, Garberville, Laytonville, Willits and down into Ukiah. These areas remained in the mid 70s to mid 80s today. Areas farther inland such as Weaverville, Covelo, and much of Lake county were in the upper 80s to around 90. Sunday is expected to be very similar to Saturday with a weak trough approaching from the west. The marine layer may slightly farther inland keeping temperatures slightly cooler than today.

Sunday afternoon the trough moves through the area. This may increase the mixing and could bring some brief clearing at the coast. This shifts the wind to more offshore by Monday morning. There are better chances of more clearing by Monday afternoon. This offshore flow should also help bring warmer temperatures the the near coastal areas 10 to 20 miles inland with many of these areas reaching into the upper 80s to low 90s. Farther inland mid 90s are expected. There is the potential that the low clouds will linger at the immediate coast and keep temperatures around 60. This will likely be the warmest day of the next week for much of the area. Heat risk is expected to moderate in portions of Lake and Trinity counties.

Tuesday an upper level low starts to approach the area and this is where model solutions start to diverge. Some of the ensemble clusters bring this low quickly north and into Washington and Oregon while the slowest solution keeps the low well off the California coast. The evolution of this low into Wednesday and Thursday will have big impacts on the forecast. This could bring the chance for Thunderstorms if the low moves onshore in northern CA. However some of the other solutions could keep hot temperatures over the area. Late in the week the models are showing zonal flow developing over the west coast. There are still some big differences whether there will be some weak ridging and dry weather or the remnants of the upper level low continuing to move through the area. Overall confidence is below normal in the extended period.

AVIATION

Widespread stratus is bringing IFR conditions with local LIFR conditions this morning. These are expected to persist into at least early afternoon. This afternoon northwest winds start to increase and this may help to clear skies for a few hours. At ACV the HREF is still showing a 25 percent chance of MVFR CIGS lingering through the afternoon. CEC is seeing a better chance of clearing and remaining clear into the evening. At KACV there is a better chance of MVFR or IFR CIGS returning in the evening. MKK

MARINE

Northerly winds are expected to increase through Sunday afternoon as an upper level trough moves out of the area. This appears to have slowed slightly, so have pushed back the start of the small craft advisory in the northern waters. Later this afternoon and evening winds are expected to be mainly around 20 to 25 KT with locally stronger areas in the lee of Cape Mendocino. The swell continues to move through the waters at around 3 to 4 feet at 12 to 14 seconds. Wind driven short period waves are expected to increase to around 5 to 9 feet Monday night.

Monday the northerly winds are expected to diminish as an upper level low starts to approach the area. Lighter winds are expected on Tuesday and Wednesday. However there is quite a bit of uncertainty in the pattern for the middle of the week so confidence is a low and many different model solutions are possible. The middle of next week there is the potential for the northwest swell to increase some as well. MKK

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PDT Monday for PZZ455.

Small Craft Advisory from 1 PM Sunday to 9 PM PDT Monday for PZZ470.

Small Craft Advisory until 9 PM PDT Monday for PZZ475.