Severe thunderstorms hit many parts of WA on Saturday, with more set to lash the state today. Multiple low pressure troughs and an embedded low pressure system have been combining with high moisture levels, cold upper level temperatures and strong wind shear to create ideal conditions for severe thunderstorms. Thunderstorms fired up over central and southern parts of the state on Saturday, bringing strong winds, large hail and heavy rain and have persisted overnight. More than 100,000 cloud-to-ground lightning strikes have been recorded over the state since Saturday morning. Some of the most severe thunderstorms on Saturday were in the Perth region, with hail as large as 3cm reported in northern suburbs. Swanbourne recorded 21mm in just 10 minutes as part of an eventual total of 33mm, its heaviest October fall since 1999. Elsewhere in the state, Ravensthorpe had its biggest rain in seven years as it recorded 64mm in 24 hours to 9am today, also its heaviest October fall in over 100 years of records. Ravensthorpe has now gained 81mm from the past two days. Also breaking a 100-year October record was Merredin in the wheat belt, gaining 49mm in 24 hours, its heaviest rain in almost four years. One storm at Esperance generated wind gusts as strong as 82km/h at about 2:30pm on Saturday. In a setup arguably even more potent than yesterday, thunderstorms are already firing over central and southern parts again and will become more widespread again this afternoon. Heavy rainfall, large hail, damaging to destructive wind gusts and even tornadoes are all a chance today, with further falls of up to 40-80mm expected across southern districts. Thunderstorms will become more isolated by Monday as the trough weakens, before clearing the state by Tuesday.