Los Angeles - Crews battling 23 tenacious wildfires in drought-stricken California rushed in reinforcements Tuesday and girded for weather that could ignite more blazes.More than 10 000 firefighters are now tackling blazes that have forced thousands to flee their homes and burned large swathes of land in the most populous US state. The biggest conflagration, called the Rocky Fire, has drawn in 3 200 firefighters."Tinder dry conditions from the drought continue to allow wildfires to burn at an explosive rate," said the California Department of Forestry and Fire Protection, or CAL FIRE.The state is bringing in extra people from southern California to the hard hit north, making already deployed firefighters work overtime and cancelling days off, CAL FIRE spokesperson Daniel Berlant told MSNBC. Resources from out of state, such as the Colorado state air reserve, are also being brought in, Berlant said.Thunderstorms that can bring lightning, the source of many fires this summer, but virtually no water, were forecast.And after a cooling of temperatures over the weekend, they are expected to rise again Wednesday, followed by more thunderstorms on Thursday, CAL FIRE said in a statement.Many of the 23 fires are actually made up of dozens of smaller lightning fires, Berlant said."Right now definitely conditions are dry. We are continuing to see the effects of the drought as wildfires can more easily spark and then they're going to spread at these historically fast rates," he said.The week-old Rocky Fire prompted evacuations as it swept through Colusa, Lake and Yolo counties north of Sacramento, the state's capital, in the north of the state.More than 13 000 people have been forced to flee homes threatened by Rocky, CAL FIRE says. Only 12% under control, Rocky has burned through more than 26 000ha , destroying 50 structures, about half of them homes.Berlant said late Monday that the fire ripped through the forests at break-neck speed, with firefighters struggling to keep apace."Over the weekend, 8 000ha burned in just about a five-hour period. That's an unprecedented historical rate of spread," he said. State completely parchedAt least 57 000ha of land have burned so far, according to figures provided by the state.California is in the throes of a record-breaking drought, with much of the state completely parched and residents asked to make major cutbacks in water use.The northern part of the state is the worst-hit by fires, where forests were completely engulfed by the infernos, and several stretches of highway were forced closed.In areas where fires had been put out, charred cars were all that was left behind on some roads, and trees were left smouldering on the blackened earth.A state of emergency was issued on Friday, and the California National Guard has been called in, underlining the scale of the threat facing the western state.A firefighter from South Dakota, Dave Ruhl, 38, was killed Thursday while fighting the Frog Fire in the Modoc National Forest outside Alturas.