textproduct: Eureka

SYNOPSIS

Above normal interior temperatures continue today. Monsoonal and tropical moisture arrives tonight into early next week, bringing chances of showers and thunderstorms early to mid next week.

DISCUSSION

High pressure continues to build over the area, bringing warm interior temperatures into the 90s to just over 100 to most interior valleys. Minor to locally moderate HeatRisk is expected with this heat. Hazy skies are possible from fires in southern Oregon and northern California, but impacts are expected to be minor.

Monsoonal moisture return again tonight into Monday. While moisture aloft will be plentiful with PW of over 1 inch, instability is still meager. Some CAMs do show CAPE of up to 200 J/kg which does bring a low (5-15%) thunderstorm threat. Dry low levels will limit any precipitation from reaching the ground, which will elevate fire weather concerns. Moisture from Tropical Storm Elida begins to stream in Monday which will continue the threat for a few showers and possibly a thunderstorm. This trend will continue through Wednesday with shower and thunderstorm chances generally increasing each afternoon with Wednesday having the highest chances. Still, chances are low at around 15% mainly in Trinity County. Uncertainty remains high as the path of the remnants of Elida will strongly influence what areas see impacts. Some ensemble members show the center of the low very close to the shore of the North Coast.

Increased cloud cover and weaker high pressure will nudge interior temperatures closer to average, though most interior valleys will still see 90s. Most coastal areas will see highs in the 60s with overnight and morning stratus. /JB

AVIATION

Stratus has returned to coast with IFR ceilings being observed. IFR to LIFR ceilings are likely early this morning with visibility impacts possible near sunrise. High pressure strengthens the marine inversion, possibly bringing more persistent stratus to the coast. NBM gives ACV a 60% of scattering and lifting this afternoon, while CEC has a 40% chance. Interior areas are likely to remain VFR for the next 24 hours. /JB

MARINE

Northerly winds continue to gradually ease and move farther off the coast. Still, the outer waters could see peak gusts of 20-30 kts today, with the strongest winds in the lee of Cape Blanco. Winds continue to ease Monday with peak gusts of 15 kts or below likely for all waters. Nearshore winds will be relatively light, and could be southerly along the coast as eddies form. Winds will generally be mild for much of the week.

Seas remain characterized mainly by decaying wind waves and small mid to long period northwesterly and southerly swells. Steep seas will slowly ease in the outer waters today and be relatively mild by Monday. A larger southerly swell, peaking at 4-5 ft from Tropical Storm Elida arrives Monday and continues for much of the week. With relatively light winds, seas could be dominated by this swell. This could create some larger breakers than usual on the southern facing beaches, especially south of Cape Mendocino.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 PM PDT Monday for PZZ470-475.