Lines of storms marched through the Northern Territory yesterday, delivering the heaviest May rainfall in as much as 56 years. The storms formed along an active trough and affected the Victoria River districts and inland parts of the Top End. Several 100mm plus totals were recorded, not entirely unusual for the tropics, but almost unheard of in May. Adelaide River topped 118mm, their best rain in three years, including the 'wet season'. The sizable total was also the heaviest in May on record, back to 1956. Even Darwin grabbed 26mm, the highest May rain in 13 years. As a result of this and a generally wet start to the dry season, much of the west and northwest of the territory has exceeded its monthly mean rainfall by around 400%. Darwin is sat at 71mm for the month so far, three times the mean of 21mm and the wettest May in 13 years. A return to drier weather is expected from Monday for much of the NT, as the trough clears east and high pressure re-establishes itself.