It turns out that La Niña wine isn't really La Niña wine


There are some good indications that this winter’s La Niña is coming to an end. Most of the weather forecast models predict that we’ll be out of La Niña conditions by the summer. The million dollar question from there is whether it will stay gone for summer, fall, and winter. Interestingly, this winter’s La Niña didn’t really have a standard effect on weather in the U.S. (remember that meteorological winter goes from December through February in the Northern Hemisphere).

Based on the previous post about La Niña (image below), it was reasonable to expect that we’d have dry weather throughout the southern U.S. and wet weather throughout the Pacific Northwest and Midwest.

Turns out, this isn’t what happened in the winter of 2020-21. Take a look at the maps below (temperature on left, precipitation on right).

Almost nothing from the winter of 2020-21 matches the typical La Niña conditions. Texas was cold instead of warm. The Midwest was dry instead of wet. The northern Plains were warm instead of cold. This teaches us an important lesson: not all La Niña winters are created equally and it is not safe to assume that the weather during a La Niña (or El Niño) winter will match our historical expectations. Other weather phenomena, such as the polar vortex that we discussed in the last post, can occur at the same time as La Niña and easily overpower La Niña’s effects.

This is an important lesson to remember as we discuss this week’s wines, which are both from La Niña years. Sometimes it just doesn’t matter!

This week’s two delicious La Niña wines are from the Southern Hemisphere. Let’s stand on our heads and get to work! (Fun fact: weather systems spin opposite ways in each hemisphere but toilets and sinks do not.)

The first is Penfold’s Bin 28 Shiraz from South Australia, Australia. The second is a Catena Malbec from Mendoza, Argentina. Although these regions are thousands of miles apart, they are nearly at the same latitude of ~33°S and 35°S. For comparison, the Ancient Peaks vineyard from the first newsletter is around 35°N, nearly the same distance north of the equator that this week’s wines are south of the equator. Interesting, right?

We should also remember that seasons in the Southern Hemisphere are reversed, so the growing season is closer to October-April instead of April-October like we had in California previously.

South Australia, Australia

For the first wine, we’ll travel just northeast of Adelaide, the capitol city of South Australia. There lies the Barossa Valley.

This wine is the 2018 vintage of Penfold’s Bin 28 Shiraz. I’ll level with you - I’ve been a sucker for Australian shiraz ever since I spent nearly two weeks there for a conference during my grad school days and drank a tremendous amount of it. So it should come as no surprise that I loved this wine - deep red, strong jam on the nose, low tannin but high alcohol mouthfeel. Absolutely perfect. 

This was a 2018 vintage, so the growing season would have begun in October of 2017, around the same time as La Niña. To first order, it’s not hard to imagine what the weather is like during La Niña events over Australia, since the water around Indonesia is, by definition warm, which results in increased rainfall.

As expected, our area of interest was on average warmer than normal (left map) during the spring and summer. However, the rainfall was slightly less than normal (right map). As we mentioned earlier, past La Niña conditions do not guarantee future conditions. Although it led to reduced yields compared to 2017’s season (which was quite a bit wetter), the grapes didn’t bloat up with extra water, which typically dilutes their sugar content and makes for worse wine.

Mendoza, Argentina

The 2018 Catena Malbec is actually a blend of Malbec grapes from 3 different vineyards around the Mendoza region.

La Niña summers in Argentina aren’t quite as predictable as in other places since La Niña has its strongest remote impacts in the winter hemisphere. The north/south temperature gradient is strongest during the winter, which provides a mechanism for the atmosphere to “pluck” the jet stream.

Summers tend to be slightly warmer around Mendoza during La Niña and there isn’t a strong rainfall relationship to speak of. The 2017-2018 growing season was pretty normal throughout Argentina. There wasn’t too much rain and temperatures were cool and consistent. In fact, this season was heralded as one of the best growing seasons in years, largely because of these typical conditions.

In the next newsletter we’ll attack common meteorological misconceptions. Stay tuned!