<span>Photograph: David McNew/AFP/Getty Images</span>
Photograph: David McNew/AFP/Getty Images

There has been an order to evacuate around the national forest in Northern California after a new fire broke out.

The McKinney fire grew to 18,000 acres in 12 hours and has no containment. It has forced officials in Siskiyou county to order the evacuees to leave their homes.

The McKinney fire grew significantly as winds from late evening storms kept the fire active through the night.

There were runs on the north and south side of the fire. The firefighters had to shift from an offensive perimeter control effort to a more defensive one.

A red flag warning has been issued by the park service. Predicted weather is expected to be problematic for the firefighters, as fire managers are expecting a very dynamic day on the fire. Lightning and high fire danger will likely lead to new fires.

The National Interagency Fire Center's fire meteorologist said that the conditions would likely start new fires. There could be a number of significant fires as well.

After an initial bout of storms on Friday, the McKinney fire grew quickly and formed a giant cloud of fire.

The area has been under a heat dome for several days. As a trough approaches, there is a chance of more lightning strikes. There is a lot of material on the forest floor because the national forest has no recent fire history.

An intense heat wave followed by the breakdown of the ridge is a classic one-two critical fire weather punch.

The Elmo wildfire doubled in size to more than 6 sq miles near the town of Elmo and the lake. The Moose fire in the Salmon-Challis national forest burned more than 67.5 sq miles in timbered land near the town of Salmon. It was almost completely contained.