Frontogenesis in a heat trough

As cold fronts move northeastwards over central Australia, they are frequently preceded by a prefrontal trough. Typically, frontogenesis occurs in the trough overnight and the trough becomes the location of a new front while the original front undergoes frontolysis. The prefrontal trough appears to be a remnant of the heat trough over the continent, which deforms and becomes mobile under the influence of the large-scale flow. It would appear that the original front is not necessary in this process and that frontogenesis can occur whenever a heat trough becomes subject to large-scale deformation. An excellent case of such a development was documented during a field experiment held in central Australia in September 1998. A detailed analysis of this case will be presented, supplemented by data gathered at Alice Springs during the passage of the front.