Over a quarter of a million lightning strikes have lit up the skies overnight over northern parts of WA as a trough deepens over the region.

About 270,000 strikes sparked across the Kimberely and northeastern parts of the Pilbara, mostly inland of Port Hedland, south of Broome and near the NT border.

One particular storm cluster developed south of Broome at about 7:30pm WST and continued all night, finally dissipating nearly 500km to the north at about 10am this morning. Over 100,000 strikes were detected from this cluster of storms alone. This cluster passed directly over Derby, bringing 36mm of rainfall, their wettest November day in 10 years.

Image: Lightning strikes, rainfall and infrared satellite of storms near Derby on Saturday morning

Another active cluster brought some short-lived but heavy rain to Kalumburu. In just 20 minutes, it recorded 27mm of rain, adding up to 40.6mm all up. Downstream, the same storm brought 14mm in just 10 minutes to Truscott. After the 50mm had fallen over Truscott, it was its second wettest November day in its short 14 year recorded history.

The trough that brought these storms is only just getting started, as more thunderstorms are likely over the region on both Saturday and Sunday. By Monday evening, there could easily have been over a million lightning strikes flash across the region.