Severe thunderstorms and heavy downpours battered the northern half of the North Island on Tuesday and more are forecast for northeastern parts of the North Island until Thursday morning.
"These thunderstorms are forming along an active cloud-band of tropical origin stretching from the Coral Sea across Vanuatu to New Zealand" said MetService's Manager of the National Forecasting Centre, Peter Kreft. MetService signalled this episode well in advance with a Severe Weather Outlook issued on Thursday 10 April. On Sunday, a Severe Weather Watch was issued and upgraded to warnings of heavy rain for Northland. On Monday warnings were extended to include much of the northern half of the North Island and Nelson. "We knew then that this had the hallmarks of being a significant rainfall event and underlined our concern with a news release",said Mr. Kreft..
On Tuesday morning at 8.29am, the warning area was extended to include Taranaki, Taupo, Waitomo and Taumarunui - which includes much of the central North Island high country. This warning highlighted that rainfall rates would be very high with intensities of 30 to 40mm per hour in localised thundery downpours. Mr Kreft said that the warning advised people in threatened areas to be on the lookout for flash flooding and rapidly rising rivers and streams.
Severe Weather Warnings for heavy rain are still in force for northeastern parts of the North Island until noon Thursday. There is a chance that, on Wednesday evening through to Thursday morning, the rain may extend back into Coromandel Peninsula,Auckland, and Waikato or into the ranges of northern Hawke's Bay and southern Gisborne and a Severe Weather Watch is in place for these areas.