Fires surround Esperance in WA's south

Lives and homes could be at risk from separate lightning-sparked bushfires burning in Western Australia's south.

Unfavourable weather conditions are worrying firefighters as they battle at least three major blazes either side of Esperance.

Watch and act warnings have been issued for North Cascade, and Stockyard Creed and Mullet Lakes in the Merivale area, to the east and west of the coastal town.

The North Cascade fire, which has burnt through close to 2000 hectares of bushland, is now moving rapidly to the south east, starting spot fires up to 100 metres ahead of the main blaze.

The fire could now threaten Scaddan, Red Lake, and Grass Patch.

Several roads have been closed to the north of Esperance, while Cape Le Grand National Park has also been closed.

A bushfire advice has also been issued for the Mount Ragged area in the northern part of Cape Arid National Park.

A watch and act alert remains in place for people travelling on the Coolgardie-Esperance Highway, 50km southwest of Norseman, in the neighbouring Shire of Dundas.