For the second time in a week, the Air Force has delayed the test detonation of a half-million pounds of explosives on the Air Force test range west of the Great Salt Lake.

The delay was prompted by bad weather and low-hanging clouds. Under certain weather conditions, the explosion could send shock waves rolling over communities along the Wasatch Front, rattling or breaking windows from Ogden to Salt Lake City.A sophisticated weather monitoring system is being used to assess and predict meteorological conditions, including temperature, cloud cover and wind direction and speed.

The detonation will test a new munitions storage building the Air Force has designed for construction at bases around the world. Two of the igloo-like buildings have been constructed at the site on the Utah Test and Training Range.

One of the igloos will be packed with 500,000 of explosives. Officials will try to gauge the effects of the explosion on that building and the one next to it.