An update from our Hydrology team regarding the recent thunderstorm activity.

This morning, MetService issued a Yellow Weather Watch over small portions of Tasman District till midnight tonight, mainly for the Buller and western part of the ranges about Golden Bay. Periods of heavy rain and possible squally thunderstorms can be expected.

While we don't normally share an update for a Yellow Weather Watch, intense thunderstorm rainfalls onto the already saturated ground following last weekend’s event will increase the risk of land slippage and falling debris on vulnerable and/or steeper sloping areas.

Thunderstorms can be highly localised and difficult to predict in terms of exact timing and location, meaning impacts may occur with little warning and in places outside the main forecast areas.

Thunderstorms may also bring short-duration high rainfall rates, gusty winds and lightning, which can create hazardous conditions, including reduced visibility for driving and rapidly changing conditions over short distances.

Smaller streams throughout the region have a high potential to rise quickly and cause surface flooding, especially in response to localised heavy falls.

Please take extra care when travelling, with potential surface flooding, debris on roads, strong wind gusts and poor visibility possible. Be aware of your surroundings, particularly in steep terrain or near waterways, and take a cautious approach.

Links for more information: