textproduct: Eureka

SYNOPSIS

Above normal warmth will continue for the remainder of the weekend, followed by a cooling trend next week. Chance for rain showers will return around mid week.

DISCUSSION

Temperatures today were 5 to 15F degrees warmer compared to yesterday as of 2 PM Sat. Upper ridge axis is forecast to shift eastward into the Great Basin on Sunday. Light offshore wind regime will once again propel high temps well above seasonal averages (5-15F) again on Sunday. Temperatures are forecast to peak into the upper 70s to mid 80's again in the interior while most coastal areas warm into the mid to upper 60s again. A few coastal valleys (Blue Lake and Fortuna) will most likely reach the lower to mid 70s again. Minor heat risk is expected again on Sunday. A downward trend of high temps is forecast to commence on Monday, though it is still forecast to remain above normal in the interior. An upper low will approach early next week (Mon-Tue). Stratus and perhaps fog will increase for coastal areas as early Sunday night as a shallow marine layer builds and onshore flow develops. Precipitation chances appear minimal Mon through Tue, though spats of drizzle or a few passing sprinkles are possible as transient shortwave trough in SW flow aloft rides over the ridge.

Precipitation chances return around mid week (Wed) as an upper low approaches the coast and meanders about offshore through Fri. Multiple outcomes are possible mid to late week. One is the upper low could remain far enough offshore as the ridge holds over the area. This would result in no precip and no chance for thunderstorms. The cut-off could also weeble wobble around offshore parallel to the Central California coast. In this case, wrap around moisture would increase the potential for interior thunderstorms Wed-Fri. Another possible outcome is for an upstream kicker to drive the trough/low complex across our forecast area Wed-Thu resulting in mostly light precip totals and no storms for NW Cal. Beyond Fri, wrap around moisture with interior showers and convection appear to be one possible outcome. Another outcome is for another colder trough to come barreling down from the NW bringing considerable cooling and perhaps more light precip. Overall not much rain potential with this large scale chaotic set-up, but cooler high temps appear very probable (>80% chance).

AVIATION

VFR conditions continue while winds remain light.

The environment remains dry with only high level clouds moving in around around a weak passing shortwave. Winds are light from the west to north Friday afternoon. Patchy ground fog was observed near some of the coastal terminals Saturday morning, but chances are lower through Sunday morning. The passing shortwave will slightly increase southerly flow and low level moisture, to begin increasing chances for marine stratus outside of this TAF period by Sunday

MARINE

Northerlies and lingering short period seas continue to decrease across the waters as a small northerly swell fades. Very light, split flow winds will remain over the waters through Monday. Northerly winds will increase behind a front late Tuesday. Near-gale to gale strength gusts are possible as early as late Wednesday, with better chances Thursday and Friday. Short period seas will likely exceed 10 ft through that period. Some small mid to long period southerly swells will also exist through the waters.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None.