textproduct: Eureka

KEY MESSAGES

* High pressure builds through the rest of the week, bringing an extended dry period for the interior and overcast conditions for the North Coast.

* Northwest gusts are expected again Wednesday with gusts up to 30-45mph for the King Range and other exposed terrain and gusts up to 20-25mph for North Coast headlands.

SYNOPSIS

Upper-level ridging builds over the West Coast this week. A warming trend is expected for inland areas with coastal areas being more likely to have morning overcast or foggy conditions.

DISCUSSION

The end of the week will be dominated the interactions of a Pacific high pressure center off the California coastline and a developing thermal trough in the wake of Hurricane Polo. This set up will lead to a more "summer-like" pattern as the week goes on. Inland areas can expect warming through the end of the week, peaking on Saturday with inland valleys reaching the mid to high 90s. North Coast areas can expect overcast skies developing each evening with areas of localized fog and drizzle. These are likely to scatter out in the afternoons. The Mendocino coastline is expected to remain relatively clear trough the end of the week with breezy north winds.

Another expected result of this weather pattern is gusty north winds along the Nort Coast. Marine waters will remain hazardous due to short- period waves caused by winds up to 35-40kts in the windiest spots. Directly along the coastline and in river valleys close to river mouths for Humboldt and Del Norte Co., expect breezy afternoons. The King Range will receive the bulk of the winds with gusts reaching up to 50kts on the exposed ridgetops as northerlies flow over the E-W orientated topography. Inland valleys are likely to see gusts up to 15-20mph in the afternoons.

This weather pattern is expected to continue through the rest of the work week and the weekend into next week. A shortwave disturbance is likely to flow over the area Sunday, yet minimal impacts are expected from this features. Only the most extreme models show any rain, albeit wetting rain >0.10", forming with this system. The GEFS and EPS ensemble models show the upper level ridge continuing through next week.

AVIATION

Marine stratus continues to force LIFR conditions for the North Coast. Satellite imagery shows an eroding marine layer from the mountains toward the coast , yet the direct coastline remains overcast. North winds will continue for ACV while southerly light winds remain at CEC, yet the forecast suggests that northerlies will eventually win out as peak heating during the day. Inland terminals will see terrain driven afternoon gusts up to 15-20mph and VFR conditions. Winds aloft near the coast around 2500 ft AGL will remain strong with possible mountain waves near the King Range and other terrain close to the coast.

MARINE

Fresh northerlies continue due to the pressure gradient between offshore high pressure and the interior thermal trough.

* Northern Inner Waters: Northerlies of 10 to 20 kt will generate steep short-period seas. A west-northwest swell at 12 to 14 seconds continues today. A Small Craft Advisory remains in effect through Thursday morning.

* Northern Outer Waters: Northerlies of 20 to 25 kt with gusts to 35 kt (mainly in the lee of Cape Blanco) will build combined seas to 10 to 11 ft. A Gale Warning is in effect until Thursday morning.

* Southern Inner Waters: Fresh to strong northwest winds of 20 to 25 kt with gusts of +35kt (mainly in the lee of Cape Mendocino) will maintain steep seas. Steep waves are likely to propagate into the coastal waters. A Small Craft Advisory remains in effect through Thursday morning.

* Southern Outer Waters: Gale force conditions develop in the lee of Cape Mendocino, where northerly winds of 25 to 30 kt with gusts up to 40 kt will yield steep, hazardous combined seas of 11 to 12 ft. A Gale Warning remains in effect through Thursday morning.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 AM PDT Thursday for PZZ450-455.

Gale Warning until 9 AM PDT Thursday for PZZ470-475.