They will be joined by US Bancorp USB.N CEO Andy Cecere, PNC Financial PNC.N CEO William Demchak, and Truist Financial TFC.N CEO William Rogers, who run the country's largest regional lenders. By Pete Schroeder WASHINGTON, Sept 20 (Reuters) - JPMorgan Chase & Co JPM.N Chief Executive Jamie Dimon plans to tell Congress that the U.S. economy faces "storm clouds," according to prepared testimony. Strong consumer spending and a robust job market suggest resilience, but snarled supply chains, the war in Ukraine, high inflation and the Federal Reserve's efforts to contain it all signal tougher times ahead, he added.