textproduct: Eureka

SYNOPSIS

An upper level low approaching will bring cooler temperatures today with some light rain tonight and early Wednesday for the north coast. Temperatures are expected to warm again Thursday before another weak shortwave brings cooler temperatures Friday and Saturday. Warmer weather is expected early next week.

DISCUSSION

The approaching upper level low is bringing onshore flow and marine stratus. This will likely keep the coastal areas fairly cloudy and in the upper 50s. The nearly coastal areas will see the most cooling on Tuesday with highs 10 degrees cooler. Farther inland in Trinity county, eastern Mendocino county and Lake county will see only a few degrees of cooling. Tuesday night into Wednesday morning the weak frontal boundary brings some light rain to Humboldt and Del Norte counties. A tenth to a quarter of an inch is expected in these counties with the heaviest rain in the mountains of Del Norte county. Farther south and east only a trace to a tenth of an inch is expected. There is still the potential for higher rainfall amounts with a 10 percent of over an inch in Del Norte county. High temperatures will be notably lower on Wednesday with areas seeing highs in the 60s near the coast and 70s farther inland.

Wednesday afternoon through Thursday high pressure starts to build into the area and most of the inland areas expected to see highs warming into the 80s. Friday and Saturday the flow starts to become more zonal and a shortwave moves by to the north of the area. This will bring slightly cooler temperatures Friday with additional cooling on Saturday. Also, gusty winds are expected starting on Thursday and increasing Friday and into the weekend. Gusts of 20 to 30 mph are possible with locally higher gusts possible in favored areas. The strongest winds are expected to be on Sunday.

High pressure starts to build in on Sunday bring a return of the heat. This will bring some offshore flow and with the ridge axis well to the west of the area this should clear out the coastal clouds. Winds continue to increase on Saturday and Sunday. Gusts of 25 to 35 mph are possible with locally higher gusts possible in favored areas. The strongest winds are expected to be on Sunday. The breezy winds along the coast and this will likely help keep the high temperatures on the coast in the low 60s. Inland areas are expected to warm into the 70s to low 80s. Early next week highs are expected to warm into the upper 80s to low 90s inland. This brings minor heat risk to much of the area on Monday. MKK

AVIATION

The approaching upper level low is bringing onshore flow and marine stratus. IFR to LIFR conditions are expected at the coastal airports. CIGS are expected to lift this afternoon to MVFR, but remain cloudy. There is stratus developing south of Ukiah in Sonoma county. This could make it north into KUKI, but at this point the marine layer looks too shallow and winds are expected to be too weak. Tuesday evening as the low continues to approach CIG may start to lift with some light rain or drizzle on the north coast towards morning. MKK

MARINE

Northerly winds continue to diminish over the waters this morning, especially in the northern waters. The seas are a combination of wind driven waves and a 10 seconds west swell. In the north, most of the water energy is in the swell, while farther south the wind driven waves persist.

Tuesday night into early Wednesday a weak front is expected to move through. This is expected to bring some rain to the area and a brief period of southerly winds in the northern waters Tuesday night. Wednesday morning northwest winds return and increase again. These are expected to reach 10 to 20 kt by late afternoon with the strongest winds south of Cape Mendocino. Winds are expected to continue to increase on Thursday with 20 to 30 kt winds by the afternoon. There may be some gale force gusts south of Cape Mendocino. Friday and into the weekend the winds continue with sustained gale force winds possible by Sunday. The steep short periods waves expected to dominate the wave environment. MKK

EKA WATCHES/WARNINGS/ADVISORIES

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

Small Craft Advisory until 5 AM PDT Tuesday for PZZ475.