Page:CAB Accident Report, United Airlines Flight 21.pdf/32

 The United States Weather Bureau accurately forecast the weather conditions which prevailed over the route and these forecasts were available to United's meteorologists and to the flight crew both before the start of the flight and en route. Prior to the departure of United 21 from New York, a trip forecast was prepared by a United meteorologist which was accurate in predicting the weather conditions to be expected during the flight. An overcast was expected in the Chicago area with a base at 1000 feet and a top at 4000 to 5000 feet. Light and moderate snow and possible light freezing drizzle was expected below 5000 feet with an inversion of temperature above 32 degrees existing over 5000 feet. According to United's procedure, the captain of the flight is required to prepare his own forecast upon the same form as the meteorologist. Captain Scott's forecast indicates he expected to find a mild to moderate icing condition with ice of both rime and glaze types in the region between Toledo and Chicago.