A list of the likely contributing factors to New Zealand's current MHW:

- La Niña
- High pressure / lighter winds
- Less mixing of the upper-ocean
- More sub-tropical air flows
- Warmer air temperatures (esp. nights)
- Excess humidity
- Climate change

Positive feedback 🔁 pic.twitter.com/5paOn8ij1T

— Ben Noll (@BenNollWeather) December 12, 2021