Weather Headlines:Seasonably warm for the coast and valleys this week with highs near to 5 degrees above average. Morning lows will be 10 to 15 degrees above normal in the mountains and deserts, elevating the heat risk. Extreme Heat Warning in the deserts and Heat Advisory for the mountains in effect until 8pm Saturday. The Extreme Heat Warning in the deserts has been extended until 8pm Saturday for high temperatures between 109 and 115 degrees. Clouds will build over the mountains each afternoon and may produce isolated showers and thunderstorms on Thursday, a slight chance on Friday, and a potentially higher chance Sunday and Monday.