Overnight storms caused flooding of homes and farmland in Chiang Rai and Lampang provinces in the North on Thursday morning and blew the roofs off houses in Samut Prakan province.In Lampang, forest runoff caused Lam Huay Luang and Lam Huay Mae Bong rivers in Thoen district to overflow and flood farmland on Wednesday night.In Samut Prakan province, on the outskirts of Bangkok, heavy rain and thunderstorms hit Muang district in the early hours of Thursday, damaging at least two dozen houses.