Heat is expected to intensify across western parts of the US and Mexico this week as a ridge of high pressure pushes temperatures well above the seasonal norm. Daytime highs are forecast to reach 10-15C above average in some areas. The US National Weather Service has issued heat advisories for parts of California and Arizona, with extreme heat warnings in force on Monday and Tuesday in places such as Palm Springs, where temperatures could reach 40-43C (104-110F). More broadly, temperatures are expected to climb into the high 30s celsius before the heat shifts eastwards towards the midwest later this week. Meanwhile, severe weather is likely to continue across parts of South Africa , with disruptive rain and damaging winds raising the risk of flooding. Rain moved in from the Atlantic across the Western and Northern Cape on Sunday morning, bringing persistent downpours over much of the weekend.…