Some advance notice, A dangerous heat wave is expected to affect much of the inland Northern part of the state, starting tomorrow. Residents should be prepared for highs soaring to 105°F in valleys from Ukiah to Weaverville, and heat advisories in effect for Mendocino, Lake, and Trinity counties. Residents in Lakeport, Clearlake, Hopland, Laytonville, and Hayfork should expect sweltering afternoons and uncomfortably warm nights. Travelers along Highways 101, 20, and 299 may also encounter heat-related vehicle issues. Power companies recommend charging devices and preparing for potential outages as demand spikes.