2:45 PM CST | January 4, 2019
Let’s take a look at this past system and how it relates to the recurring cycle theory. This is yesterday evening’s 500mb analysis of our atmosphere. This shows the features in the mid-levels of our atmosphere. You can see a closed low near the Red River at 6:00 PM CST January 3rd. (The time on the graphic is in UTC/Zulu time - not central standard time.) The next graphic shows the conditions 51 days before - 6:00 PM CST November 13th. One may think - well, of course you can cherry pick two random systems. Let's take a look below at the system just after Christmas.
The system the day after Christmas brought severe weather to parts of the state. This graphic shows this system at 6:00 PM CST December 26th as it was moving into the region. This system was directly related to the same part of the pattern we saw in early November, about 52.5 days earlier. This can be seen with the last graphic. The primary difference is that the late December system was stronger and farther south than the early November system. When the second cycle first began, it had a preliminary cycle length of 53 days. The last two systems are bringing the mean cycle length down a bit, closer to 52 days.
The weather that has unfolded was pretty much as discussed last month - just a little earlier as the mean cycle length continues to be refined. The systems this winter have been farther south and a bit stronger than this fall due to the seasonal differences in the jet stream. Nonetheless, the same features have come into play and will do so again later this winter, this spring, and all the way until next fall when the new weather pattern sets up. It is remarkable to watch unfold.
What causes a new weather pattern to set up each fall? The founder of the theory, Meteorologist Gary Lezak in Kansas City, believes that it likely has to do with the Autumnal Equinox at the end of September. It basically "resets" the weather pattern. While the theory does not guarantee a particular outcome, it gives you an idea of when pieces of upper-level energy could impact the region and how they may evolve. The theory allowed us to make a prediction 17 days out that a system would impact us around Christmas and colder weather would return by the end of the month/early January. As we got a little closer, I mentioned that I would be watching around January 5th for a system and that the risk for winter weather in our part of the country would be elevated during the first week of January. It just amazes me how this theory has not gained more traction in the meteorological community. It is a valuable tool that helps with long-range model verification as you can "throw out" unlikely scenarios from the model guidance days out. Meteorologist Gary Lezak presented his theory at the American Meteorological Society meeting last year. At the time, he made a prediction 200+ days in advance that there was a 75% chance of a hurricane in the eastern Gulf of Mexico within a few days of September 1st. Tropical Storm Gordon made landfall near the AL/MS state line Tuesday evening, September 4th with maximum winds of 70 mph. Wind gusts just above the surface exceeded hurricane-force (>74 mph) with a wind gust of 78 mph reported at Fort Morgan, Alabama 118 feet above the surface. Despite all of this and much more, there are those who remain skeptical of the idea that our weather pattern cycles.