Iron-ore’s 2016 rally may be about to face a challenge from the changing of the seasons. Morgan Stanley has forecast that prices may tumble back to $40 a metric ton this half as the approach of winter in China typically blunts steel demand and output. “Our short-term forecast still features a September-October seasonal pullback as China’s steel demand and production rate abates,” analysts including Joel Crane wrote in a report. Over the past 10 years, iron-ore prices have on average dropped in September, October and November, according to the report.