textproduct: Eureka

KEY MESSAGES

* Today is the last day of warmer temperatures for interior areas.

* Cold front most likely to cross the area Monday into Tuesday. 20-30% chance of wetting rain along the North Coast.

* Cooler temperatures with a slight chance of lingering showers through the week.

SYNOPSIS

Warming peaks today inland and along the coast where marine influence remains weak. Cooler and more moist conditions build through the weekend into next week.

DISCUSSION

The upper level ridge that has been warming temperatures all week for NW CA will begin to flatten this evening. With this shift in the synoptic set up, expect cooler, more seasonable temperatures Saturday. The marine layer is also expected to rebuild this evening giving the North Coast a higher chance of fog and decreases chance of cold morning tempertures under 40F. An upper level trough currently situated over Alaska is expected to pass by the forecast area Sunday afternoon, causing further cooling inland for Monday. Rain chances are also highly variable due to the frontal system remaining off the coastline. While the chance for any rain (>0.01") is around 20-50% for all areas outside of Lake County, yet wetting rain (>0.10") remains limited to Del Norte and Humboldt coastline with only a 20-30% on Monday. This means that very light rain is more likely than any impactful rainfall from this system through Monday into Tuesday morning.

Through the coming work week, expect valley fog each morning as PWAT values increase to near or slightly above normal. Limited coverage of light rainshowers is possible through the week as well, especially for higher elevations. Relatively unsettled weather is likely to remain through the coming work week as this low pressure center remains over the western US into next weekend. DS

AVIATION...18Z UPDATE

Mainly VFR is expected for the coast today. Coastal stratus has begun to rebuild and could impact ACV around 02Z. LIFR conditions are expected through the night for North Coast terminals. Winds will remain relatively light <8kt through the TAF period. Stratus is expected to dissipate as through Saturday morning leading to VFR conditions for the North Coast. Inland terminals can also expect VFR conditions with light to locally moderate terrain- driven winds through the afternoon.

MARINE

Light winds are expected to continue through Saturday early morning. The waves will remain dominated by a northwest swell and a more southerly swell. The northwest swell is around 5 feet at 12 seconds while the south to southwest swell is around 3 feet at 15 seconds.

Saturday morning, northwesterly winds are expected to increase into the waters. These are expected to first increase in the southern waters and then expand north Friday night and Saturday. These are expected to be fairly shortlived and start to diminish on Sunday and especially Sunday night. Lighter winds are expected early next week and they may be southerly. Mid- week northerly winds are expected to increase again. MKK

FIRE WEATHER

Today is expected to be the hottest and driest day for the forecast area through the next 7-10days. ERC values will remain at the 80th percentile through the afternoon leading to moderate to high fire danger. Winds inland have eased however.

Over the weekend, a fairly significant cooling trend will take effect as a low pressure system and its associate cold front impact NW CA. This will likely lead to a slightly more unstable atmosphere, cooler daytime temperatures and increased overnight recoveries. Wetting rain is not likely, around 20-30% for coastal areas of Humboldt and Del Norte county, yet there exists a very slim chance of showers elsewhere. That said, rain accumulation will likely be below 0.10" and should have minimal operational impacts. Cool and moist weather is expected through the coming work week. DS

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 3 PM Saturday to 3 PM PDT Sunday for PZZ470.

Small Craft Advisory from 9 PM this evening to 3 PM PDT Sunday for PZZ475.