textproduct: Eureka

KEY MESSAGES

* Interior areas continue to experience near or slightly below normal temperatures through this weekend.

* Coastal areas continue to see overnight stratus with occasional afternoon clearing.

* A troughing pattern continues next week to bring more below average temperatures and chances for precipitation.

SYNOPSIS

Generally mild, seasonable weather continues across the area with slightly below normal interior temperatures and coastal areas seeing overnight stratus. A troughing pattern continues next week, brining below average temperatures and chances for precipitation.

DISCUSSION

Midday radar showed shower activity spreading northeast and into over portions of Lake County, though precipitation was yet to be recorded at the surface. The tropical moisture quickly departed going into the later afternoon hours.

Interior temperatures will be near or below average from the troughing. The marine layer has also undergone deepening, allowing for further intrusion inland. The low inversion strengthened Friday with temperatures warming to the mid 70s to 500-600 ft. This cap and light westerly flow held the coastal stratus in a little longer Friday. There does seem to be some better shots of clearing through the weekend for the coast.

A passing trough will increase northwesterly to westerly winds Saturday. The interior ridges and channeled terrain have a high chance from NBM of seeing gusts over 20 mph. There are more isolated but still sold chances for gusts over 25 mph, and locally up to 30 mph for the described locations. This will create some fire weather concerns, though the environment will be trending more moist in time.

A cutoff low is modeled to form and sweep into Northern CA Tuesday. very little precipitation is forecast from this system. Models have been struggling will the latitudinal placement of this low along the California coast, but there may be instability with it. NBM is currently holding some 10-15 percent chance of thunderstorms Tuesday, but much could change with this if the low tracks farther south.

This does seem to mark the beginnings of a pattern change towards more active troughing and additional chances for rainfall, and perhaps more unstable type systems. In fact, dusting off the seasonally dormant cluster analysis tool, there is strong support for a stretch of troughing influence through at least next week. NBM probabilities drop off pretty quickly for rainfall totals over 0.3 inches for the period Wednesday through Friday however. The main concern would be how convective the various systems end up being.

AVIATION

18Z TAFs.Areas of coastal stratus will undergo some scattering through the afternoon Wednesday, but will generally persist along the coast and coastal terminals. Winds will be light, with some occasional afternoon northwesterly gusts. The stratus will fill in quickly going into the evening. IFR to LIFR conditions are forecast to return overnight. Troughing in the region should limit the duration of any fog that develops through Saturday morning, and may hold more consistently to IFR ceilings than LIFR if further deepening occurs.

MARINE

Apart from areas around and south of Point St George, winds in the inner waters north of Cape Mendocino remain generally light. Otherwise, the northerly winds will strengthen across the waters through the weekend. Gust up to 35 kts can be expected around Cape Mendocino through the afternoons and evenings. An isolated area of gale strength gusts will expand farther into the southern outer waters late Saturday and into Sunday. Steep wind driven seas of 7 to 10 ft will develop as a result. The northerlies will begin to quickly subside Monday as a troughing pattern returns. Seas and winds look to be quite low for much of next week from the troughing pattern. A stronger front with a round of increased southerly winds will be possible around mid next week however. A long period small southerly swell around 3 feet will also enter the waters Saturday.

FIRE WEATHER

Minimum relative humidity will begin trending higher Saturday. The marine layer will remain deeper, allowing for for further intrusion inland. A passing trough will increase northwesterly to westerly winds Saturday, mainly through the afternoon hours. Gusts of 20 to 25 mph and locally up to 30 mph are likely for the interior ridges and channeled terrain. Relative humidity values will continue trending higher through next week with a continued troughing pattern, bringing some chances for rainfall and below normal daytime highs. NBM is bringing some slight chances (10-15 percent) of thunderstorms with the Tuesday system, but models are very inconstant with available instability and where the trough tracks in.

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 PM PDT Saturday for PZZ455.

Small Craft Advisory from 3 PM Saturday to 10 PM PDT Sunday for PZZ470.

Small Craft Advisory until 10 PM PDT Sunday for PZZ475.