In the week I have received several questions about why this winter, which was predicted to be warmer and drier than usual, has been so cold. Here is a response I wrote to Bob Kemerait, UGA, about this winter’s crazy weather and the lack of warm weather (so far). You might find it helpful too.
La Nina was not officially declared until earlier in January, so we have been skirting with neutral to weak La Nina conditions for most of the past few months. Neutral years and weak La Ninas both have the capability of having cold outbreaks occur because the circulation around the North Pole is weak and so lobes of the coldest air can push down into the mid-latitudes, and that is what we have been seeing. Since this La Nina is likely to be weak and last for only a few months before we go back to neutral conditions, we may see more of these in the next couple of weeks or months. In spite of the cold outbreaks, though, it has not been as much below normal as you might think. The graph below shows the daily temps compared to normal and extremes (green is normal, red extreme highs, blue extreme lows, gray is this year’s data) for Albany (Tifton had some missing data). We have had cold weather, but in between we have had temperatures that have been warmer than normal. Today (Friday January 17) it is supposed to get to 60 F in Athens, which is definitely above normal for mid-January, which is usually just about the coldest week of the year. Albany’s average temperature so far this winter is ranked 37 out of 120 years of data, so while we are colder than average, we are not near a record-setting winter even with the cold outbreaks so far.
While the winter has been colder than normal so far, it has also been drier than usual, as we expect with La Nina, in spite of the storms we have had go through. As far as I am concerned, any precip we get over a La Nina winter is probably a good thing going into the next growing season, since La Nina springs often see early season dry conditions and even drought due to the lack of soil moisture recharge over the winter.
We also need to keep in mind that we are still only halfway through winter. The long-range climate models show that a big change in the weather pattern is expected near the end of January to a much warmer pattern, so that will counteract the cold we have been having this winter so far. Depending on how warm it gets in February, we may be much closer to normal overall than it feels like right now. My biggest concern at the moment is the fruit farmers, because they have had plenty of chill hours this winter already, and if we have a long warm spell in February, we could see an early bloom and the potential for another damaging freeze if another cold outbreak comes late in February or in March as it did in 2023.
Of course, we also have to keep in mind that predictions for La Nina winters are based on probabilities, and even if 8 out of 10 years follow the expected pattern, that means two years don’t, and maybe it’s just one of those years. Every El Nino and La Nina is different because they are linked to what is happening around the rest of the globe.
If you are interested in reading more, here are a couple of related articles that you might find helpful in understanding what we are seeing this winter:
AgWeb: With More Arctic Air Set to Blast the U.S., Why This Winter Could Be Remembered for Its Extremes
USA Today: Arctic blast about to invade US. What happened to warm winter predictions?
