What's the weather doing this season?

The Growing Degree Days (GDD) figures for Lincoln through March 13th don't make for pretty reading!!

Currently we sit at 686 GDD (base 10, calculated on a daily basis) while the long term average (LTA, 1931 through 2010) to this point in the season is 812.

 Figure showing the growing degree days for Lincoln, Canterbury based on daily calculations at base 10C

December was the only decent month, having a heat accumulation close to that of LTA, but November, January and February were all cooler than LTA to the tune of about 85% of the value.

Rainfall is about aligned with LTA, the current season to March 13 being about 18mm greater than the LTA of 441mm.

Often, we get a nice March and early April after seasons where the early months' temperatures have been lower than average, but so far this doesn't look like it's happening, with the weather patterns seemingly stuck on cool and unsettled.

The Seasonal Forecast for New Zealand (http://www.niwa.co.nz/seasonal-climate-outlook-march-may-2012) indicates they are expecting more winds from the north-east, which for many of the growing regions in New Zealand, which are along the East coast of the country, means cooler temperatures.

When I look back at the pattern of heat accumulation for Lincoln Uni since the 1998-1999 season when I first arrived in Canterbury, this is the coolest season of them all, bar the 2000-2001 vintage. It's also been a remarkably consistently cool season, whereas in other years it tends to be warmer than LTA at first, then cooler nearer to harvest or vice versa.

So what does this mean for vintage? As long as the fruit stays free of disease (which we've been encouraging through an open canopy), we should be all right. Any opportunity to drop off crop that is tailing behind the average in terms of ripening is a good idea, as well as keeping the canopy open so the fruit dries out more quickly and also gets warming by the sun. We also have to hope that the night-time temperatures don't get too low, as this can be a signal for the vines to get ready for winter and start dropping their leaves! We've already had a couple of nights near 3C!

Our own vineyard, in which we're growing Pinot noir (and a bit of Pinot meunier) for sparkling wine is about 10km from the Lincoln Uni vineyard, but we're harvesting very shortly as the fruit is up to 19 Brix. In a season like this, this show the value of site selection (our vineyard is on the Port Hills and protected from the easterly (and cool) winds), good canopy management and end use of the grapes (sparkling wine, so they are harvested earlier). Of course, that isn't saying anything about how easy it is to sell the wine!

I suppose the good news out of all of this bad weather information is that the December temperatures were reasonably warm, which should mean we still have a decent initiation of flower clusters for the 2012-2013 vintage. 

At least we will have a promising potential to work with!!