WeatherWatch.co.nz is monitoring some big cloud build ups from Waikato to the South Island today, with the government forecaster, Metservice, now also watching them – putting out a Severe Thunderstorm Watch for inland Canterbury today.

Since Monday WeatherWatch.co.nz has been predicting the risk of afternoon heat showers around the Southern Alps, Central Plateau and Waikato region.

Even at 9:15am large cloud build ups have already been spotted.

As the day continues to heat up, sea breezes are likely to form – leading to convergence zones (where opposing winds meet and can significantly pushing up the cloud tops).

While thunderstorms may be more isolated, heavy showers are predicted to pop up in some inland areas between Otago and Waikato, with the odd shower possible in surrounding regions too.

These types of showers can cause localised flash and surface flooding – as we’ve seen in recent days across Waikato and Auckland.

– Homepage image / File, big thuder clouds over inland Canterbury, John Gaul

– WeatherWatch.co.nz