Sunshine and extreme heat, that’s what is in store for much of California and other areas of the western U.S. during the last stretch of Spring. After some cool rainy weather days in many areas of the West, with daytime temperatures 10 to 20 degrees below average, a drastic change in the weather pattern is on the way. Between mid-week and the weekend, the jet stream configuration will experience a noticeable change, and while it pushes well to the north high pressure will build into much of the southwest increasing sunshine and heat.