Multiple emergency level bushfires in the southern half of WA are stretching services to capacity, but affected residents have been unable to access critical information about the fires thanks to a website and app failure.

An emergency warning has been issued for part of Chittering and Bindoon, less than 70 kilometres north of Perth.

Residents in Nambeelup, about 16 kilometres east of Mandurah, had been urged to leave and there is an evacuation centre at the Murray Aquatic and Leisure Centre.

The warning level for that blaze was downgraded to a watch and act alert at 4:20pm.

Meanwhile, about 250 firefighters are responding to two separate emergency fires in the Mid West, near Warradarge and Mogumber.

There are a dozen further blazes at the watch and act level with residents being warned to prepare to leave or monitor conditions. 

Website, app down

But at a time when five separate fires were burning at emergency level, the Emergency WA website crashed and was not able to show current bushfire or other warnings.

No details were available on outages and closures, incidents, natural hazards or prescribed burns for more than two hours.

The website appears to have since been restored.

DFES posted a statement to social media acknowledging the communication breakdown and attributing it to technical difficulties.

The agency is encouraging people to listen to local ABC radio to keep up to date or to call 13 3337.

Lightning blamed

Department of Fire and Emergency Services (DFES) Assistant Commissioner Paul Carr confirmed the Nambeelup and Chittering blazes were likely sparked by lightning.

Large smoke clouds billow into the air over a rural setting.

Eneabba was evacuated on Sunday when a blaze sparked by lightning was threatening lives and homes.   (Supplied: Jackson Whooley)

Meanwhile, the fire in Warradarge has razed at least 7,000 hectares of scrub and farmland since early Sunday morning.

Parts of Brand Highway have been closed, with flames burning on either side of the road.

Earlier, an emergency warning in place for Brigadoon and Gidgegannup, about 40 kilometres north east of Perth, was downgraded around 3:30pm.

Firefighters are continuing to strengthen containment lines, as the fire is stationary, however, uncontained and uncontrolled.

An aerial view of a bushfire.

The Brigadoon fire seen from the air.  (ABC News)

The Bureau of Meteorology has issued a severe thunderstorm warning for parts of the Central West, Central Wheatbelt and Great Southern Districts.

Senior meteorologist Jess Lingard told ABC Radio Perth thunderstorms were producing damaging wind gusts in the area, including potentially Dalwallinu, Dowerin, Wongan Hills, Beacon, Cunderdin and Kellerberin.

But she added there was “good news” because the west coast trough that is driving the current hot fire conditions will shift towards the east overnight and should produce milder conditions tomorrow.

Storms since Saturday night have caused widespread power outages, peaking at at 115,000 properties in the Perth metropolitan, the Midwest and the Wheatbelt regions.

Local emergency responders said telecommunications were impacted as a result.

By about 4pm Western Power said around 15,000 properties continued to be affected, with the utility still responding to 52 hazards across the network.

A wall of thick smoke spreads across a paddock of grain crop.

Power outages across the Midwest made it challenging for fire fighters to respond to an emergency level fire in Howatharra on Sunday.   (Supplied: Andrew Vlahov)

Suspicious blaze

On Monday, as firefighters struggled to contain a number of fires, a fire east of Perth appeared to be deliberately lit. 

The blaze in parts of Chittering, Julimar and Moondyne, was fanned by strong winds and spot fires jumping containment lines.

DFES incident controller Murray McBride said the fire, threatened properties. 

It has now been downgraded to an advice level with firefighters still on the scene mopping up.