Regional council's climate scientist Dr Kathleen Kozyniak says the definition of 'drought' is near impossible to pin down. She chats to Mark Story.
Just how real is the threat of drought for the Bay, and what needs to happen for it to be official?
Summers in Hawke's Bay often carry the threat of drought and you can count this summer among them. The region is progressively drying out and there's scant prospect of substantial rain on the horizon. Hopefully we'll get some helpful splashes this Sunday.
There are numerous types of drought - meteorological, hydrological and agricultural to name a few - and a bewildering number of indicators and indices of drought. Droughts are, in the words of the World Meteorological Organisation, slow creeping. Their insidious nature combined with no "one size fits all" measure, makes the point of officially being in drought a very nebulous thing to pin down. I don't think anyone quibbles about liberal use of the "d" word when the Ministry for Primary Industries starts gearing up support for primary producers and labels the dry spell an adverse event.
What's the biggest contributor to the dry conditions: the lack of rain, or winds?
The biggest contributor is the lack of rain. The winds have an exacerbating effect but you hit a stage when there's little moisture left for them to sap. If we had the winds and a decent amount of rain, we'd be called Wellington and I'm not aware alarm bells are ringing there yet. If we had the lack of rain and less wind, we'd be called Northland, which appears to be looking down the barrel.
How good is the science behind predicting such dry weather events - as opposed to a decade ago?
Here I'll drag out the well-worn phrase that weather prediction is, for a number of reasons, not an exact science and long range forecasting, in particular, can be a soul destroying exercise.
The understanding of what drives our seasonal climate is constantly improving. A number of broad scale circulation patterns, such as El Niño-Southern Oscillation and a raft of others, influence New Zealand's weather. Monitoring and predicting the status of those climate phenomena is better than a decade ago. Their presence in certain phases raises the risk of certain weather outcomes for New Zealand but never guarantees them.
That's where the difficulty lies in seasonal forecasting. It takes just a 1-3 day window, in three months of sunshine, for an oddly named storm to turn parched earth into a flood course and a forecast of low rainfall into a mockery.
Have you worked in more pluvial regions or is the infamous East Coast dry your preferred terrain?
Will I get sacked if I say I love a good drought? Actually, I love arid daylight hours but it can happily toss down at night. I was born and raised in Hawke's Bay so I'm in my comfort zone weather wise. Other places I've lived are Hamilton, London, Bristol and Wellington. Bristol and London were for me a Vitamin D deficiency shock. I'd say Hamilton weather isn't so much pluvial but more akin to wrapping yourself in damp cotton wool (winter mainly). Wellington isn't particularly rainy but encase its weather in metal and put a trigger on it, and it'd be considered a weapon.