A widespread bout of severe and unsettled weather is set to affect large parts of both the North and South Islands today, with authorities warning of damaging hail, intense downpours and hazardous driving conditions.
According to MetService, a cold and unstable air mass over the South Island is bringing a moderate risk of thunderstorms to areas including Christchurch, the Canterbury Plains and High Country, North and Central Otago, Dunedin, Clutha and Southland from early afternoon through to the evening. Some storms may turn severe, with hail larger than 20mm possible. Forecasters warn such hail could cause significant damage to crops, orchards, glasshouses and vehicles, while also making roads dangerous.
At the same time, a complex trough moving across the upper North Island is expected to trigger thunderstorms and heavy rain in Northland, Auckland, Great Barrier Island, the Coromandel Peninsula, the Bay of Plenty and Rotorua from mid-afternoon into the evening. There is a moderate risk of severe thunderstorms producing intense downpours of 25 to 40mm of rain per hour, raising the risk of surface and flash flooding, particularly in low-lying areas, streams and narrow valleys. Slips are also possible, and motorists are urged to take extreme care due to poor visibility and water on roads.
Further east, parts of the Bay of Plenty and northern Gisborne face similar conditions later tonight, with thunderstorms and heavy rain forecast between 7pm and 11pm. Forecasters say rainfall rates could again reach levels capable of causing rapid flooding and hazardous travel conditions.
In addition to the thunderstorm watches, heavy rain watches are in place for several North Island regions as a front moves northwards today and overnight. Areas under watch include eastern Bay of Plenty (east of Whakatāne), Taranaki Maunga, the Tararua Range and Wellington. In some locations, rainfall totals may approach warning thresholds, with a moderate chance some watches could be upgraded.
MetService says a Severe Thunderstorm Watch means conditions are favourable for severe storms and urges people in affected areas to stay alert for rapidly changing weather and possible warnings. Residents are advised to take shelter immediately if threatening conditions develop and to keep up to date with the latest forecasts and safety advice from Civil Defence.
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Dear Met Service please try and get things right next year. Maybe look at Zoom satellite or null school. They will help with the weather. All the best and good luck.