Heat Wave Sizzles Western US States

The heat wave began last week after a large high-pressure center developed over Arizona. Weather pattern was pushing that high-pressure center north into Canada, but most of the West is expected to experience high temperatures into next week.

Temperatures climbed so high across much of the West on Thursday that authorities warned residents of southern Nevada, southeastern California and northwestern Arizona that outdoor activities could be dangerous except during the cooler early morning hours.

The heat and a dry spring has raised concerns among firefighters across the West.