textproduct: Eureka

SYNOPSIS

High pressure is forecast to remain over NW California through the weekend resulting in dry weather and generally above normal daytime temperatures. Overnight and morning temperatures will remain chilly with night and morning fog in river valleys.

DISCUSSION

An upper level ridge has situated itself over the West Coast leading to large scale subsidence and adiabatic warming. Anomalous interior warmth with temperatures above climatological norms will continue under the strong ridge. With clear skies and exceptional longwave cooling, it will continue to remain cold in the river valleys each night and morning, especially in northern Humboldt, Trinity and northern Mendo through the end of this week. The ridge aloft will continue to provide dry and stable weather conditions for NW California through the weekend. The anomalous interior January warmth is contributing to a strong inverted trough and elevated northeasterly winds, especially over the ridges.

Early Saturday morning, satellite indicates a stratus deck approaching Northwest California, particularly close to the Mendocino coast. However,the offshore flow is greatly reducing the chances for coastal stratus and fog to make it onshore. Chances for the ridge to weaken or breakdown do not increase until the middle of this coming week. Probabilities for meaningful rainfall over 0.1 inch do not increase until late next week and next weekend. After another prolonged stretch of dry weather, wet weather will likely return for the latter part of January for NW CA.

AVIATION

The stratus remains off the Mendocino coast this morning. Any vis/cig reductions at KACV and KCEC look like they will be locally generated this morning. Confidence is low on whether this will form and if it does it will likely be intermittent. The offshore flow looks to keep stratus away through most of the daylight hours on Saturday. There is more confidence in the stratus making it onshore Saturday late in the afternoon and evening. Inland the northern valleys that have been seeing fog will likely see it this morning. KUKI will likely remain clear again as well. Winds will generally be light, aside from the easterly winds over the higher terrain. MKK

MARINE

Northerly winds remain around 5 to 10 kt with some very light wind chop. These winds are expected through Sunday morning. Waves have dropped to 4 to 5 feet and these are expected to continue through Sunday morning.

Sunday afternoon or Sunday night northerly winds winds are expected to return and increase to 15 to 20 kt on Monday. There are still some differences in the models on how strong these will get, but most models keep them below 20 kt. These winds are shortlived and expected to diminish by Tuesday.

Monday night and Tuesday the GFS wave model is showing a long period wave moving in and building to around 5 to 6 feet. MKK

EKA WATCHES/WARNINGS/ADVISORIES

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