Temperatures will be at full throttle later this week in the West, challenging records and elevating the wildfire threat.
The weather this week will favor an expanding area of sunshine and building heat over the West. As temperatures soar to record-challenging levels, dry fuel and the potential for spotty dry thunderstorms will push the wildfire threat to new areas and raise the risk in other locations.
Building heat, drought and the risk of wildfires could result in a fireworks ban in some communities as Independence Day activities increase.
The pattern bringing clouds, showers and cool air to the Northwest will gradually erode, dissolve and disappear.
Once the pattern sets up, the heat wave will last through next week in many areas. Grassy and wooded areas that are green now may become dry fuel for fires as the atmosphere heats up.
Cities that will experience record-challenging heat during the pattern into next week include Las Vegas, Phoenix, Salt Lake City, Denver, Boise, Idaho, Rawlins, Wyo., and Fresno, Calif.
With time, the heat can expand to part of the California coast by way of a slight offshore flow.
The system producing the heat and sunshine will allow widely separated, pop-up thunderstorms with time. Most of the storms will form and die over the mountains, but there will be a few exceptions.
A few locations can receive a downpour. However, many of the storms will bring little or no rainfall. This phenomena, commonly called "dry lightning," can spark new wildfires.
While the natural spark for wildfires cannot be avoided, people are urged to be very careful when using outdoor power equipment and open flames. Never park a vehicle that has been running for any length of time over dry grass and brush as the hot exhaust can start a fire.