KARACHI The PCB Umpires Refresher Course, which was to be held from August 7 to 8 at National Stadium Karachi, was postponed due to prevailing conditions of weather in Sindh and Balochistan. New dates will be announced later, the PCB officially announced Wednesday. The PCB has already organised two-day refresher courses for umpires for all panels of umpires at Diamond Cricket Ground Islamabad and Gaddafi Stadium Lahore.