textproduct: Eureka

KEY MESSAGES

* Interior areas continue to see slightly below normal temperatures through this weekend.

* Coastal areas continue to see stratus continuing into the afternoons for the remainder of the week.

* Tropical moisture may bring a few showers to Mendocino and Lake Counties Thursday and Thursday and Friday.

SYNOPSIS

Slightly below normal interior temperatures likely through the weekend. Coastal stratus remains persistent through the rest of the week. Tropical moisture arrives to the area Thursday and Friday which may bring rain showers to Mendocino and Lake Counties.

DISCUSSION

An upper-level trough remains in place over the Pacific Northwest. This has moderated interior temperatures with highs in the high 80s to low 90s for most interior valleys. The coast has been experiencing more persistent coastal stratus with minimal and brief afternoon clearing. This is expected to keep coastal temperatures in the low to mid 60s through the end of the week. A deep marine layer also brings stratus farther inland, which is moderating some fire weather concerns, especially closer to the coast. This trend continues for the remainder of the week.

Thursday into Friday, as southwesterly flow aloft remains in place over the area, moisture from the remnants of Tropical Storm Iselle, currently off the coast of Mexico, will arrive into central and northern California. It is uncertain just how much moisture will be over northwestern California, with modeled precipitable water values ranging from about 0.8 to 1.5 inches over southern Mendocino and southern Lake Counties by Friday morning. Should this be on the higher end, showers are possible over the southern portions of the area. Otherwise, much of this moisture is unlikely to reach the ground with drier lower levels. At this point, instability is near zero which will limit any thunderstorm chances and NBM currently has thunderstorm chances at less than 5%. This will need to be watched closely over the coming days.

This weekend, a trough in the Pacific Northwest rebuilds and is modeled to be slightly stronger and farther south. This will continue the moderated interior temperatures (highs in the 80s to low 90s), and possibly bring coastal drizzle and even more persistent coastal stratus into the afternoons. Coastal high temperatures are also forecast to drop into the high 50s to low 60s. Early next week, a stronger trough drops from the Pacific Northwest. This is expected to bring cooler temperatures and could even bring early season rain to the northern portions of the area. Stay tuned! /JB

AVIATION...(6Z TAFs)

A deep marine layer has reestablished itself along the coast bringing MVFR stratus impacts to ACV and CEC. IFR stratus is possible early Wednesday but these will lift after sunrise. Scattering is possible for a few hours in the afternoon, but clouds may only retreat to the immediate coast and imp. For the interior, outside the near-coast river valleys, VFR conditions will prevail for the next 24 hours. /JB

MARINE

Light winds continue today outside of breezy northerlies in the lee of Cape Mendocino. Outside the lee of the Cape, seas are dominated by a mid period southerly swell at around 3 to 4 ft. Northerly winds increase Thursday into Friday with widespread gusts of 20 to 30 kts likely for the outer waters. Despite lighter winds nearshore, steep seas of 6 to 8 ft may propagate nearshore. Winds increase farther this weekend with near-gale to gale force winds likely for much of the outer waters. /JB

EKA WATCHES/WARNINGS/ADVISORIES

CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory from 3 PM Thursday to 9 PM PDT Friday for PZZ475.