UGA Extension Viticulture Blog

Climate outlook for the 2018 growing season

In spite of what seemed like very cold temperatures over the winter, the April-like temperatures we experienced across the Southeast in February have left us well above normal in temperature for the year so far. February 2018 was the warmest February on record for Georgia and all of the Southeastern states. Precipitation has been less than normal in most of the Southeast since January 1, which led to an increase in drought conditions earlier in the year. Fortunately, recent rains have helped with the drought in Alabama and northern Georgia but has largely missed southern Georgia, where soil moisture remains low. Cooler conditions and a bit more rain in the next week should help with those conditions to some extent.

Looking ahead to the growing season, we are coming out of a moderate La Niña event and are expected to be back in normal conditions by late spring. Often when this happens we see dry weather in May and June. The long-range forecast from NOAA’s Climate Prediction Center (http://www.cpc.noaa.gov) indicates that we will have equal chances of below, near or above normal precipitation for March and for March-May, which means that there is no real skill in their forecast and you should just use watch the changing weather conditions to see what pattern sets up this spring. The temperature forecast for March does not lean one way or the other either. Based on my look at long-range weather forecasts, I think it is likely that the southern half of Georgia has already experienced its last freeze, but I expect to see a couple more cold outbreaks this month that could get down below freezing in the northern half of the state. Looking ahead on temperature, based on long-term trends, above normal temperatures are more likely to occur than normal or below normal temperatures for most of the next year. That will increase water demand even if we get a decent amount of rain.

The summer following a La Niña winter often experiences drought conditions, and I don’t think this year is likely to be an exception. As long as you have water available, it could mean reduced pressure from fungal diseases and pests, a good thing for grape growers.  But the neutral conditions also mean that Atlantic tropical storms are more likely than usual again this year, and if one tracks over your area, you could see damage from winds or heavy rain. Unfortunately, there is no way to know at this point where those storms will go, so that is something you will have to watch through the tropical season. It would not surprise me if we get a storm or two early in June or possibly even in May because the Gulf of Mexico temperatures are so warm right now, but those are more likely to be rain-producers than high-wind events.

Here are some resources you might find helpful when looking for spring freezes. If you are interested in following the weather patterns ahead for the next couple of weeks, you can find more information on how to access them at my blog post at https://site.extension.uga.edu/climate/2018/02/have-we-seen-the-last-frost-of-the-year/. There is also information on where to find frost climatology information. The forecast maps clearly show two or three freezes covering at least the northern third of Georgia by the third week of March, which is as far out as these forecasts go. Because of the high likelihood of frost in the northern counties, the National Weather Service has not even started doing its spring freeze warnings for those counties yet. You can read more about their freeze warning system at https://site.extension.uga.edu/climate/2018/03/frost-freeze-program-for-north-and-central-georgia-is-now-active/.