In the 1940s, Jerome Namais, a meteorological researcher, discovered what he called the “Index Cycle” and found that it is possible to make long-range predictions for winter based on what occurs in fall. Namais laid the groundwork that would become the CPH (Cycling Pattern Hypothesis) written by Meteorologist Gary Lezak. Lezak discovered the LRC (Lezak’s Recurring Cycle) independently and learned of Namais’ work later. The Heady Pattern was discovered by meteorologist Doug Heady, independently and is essentially the same as the LRC with a few differences. Paraphrasing the theories “a unique weather pattern sets up in the fall and semi-permanent anchor troughs and ridges are established. A cycle Length evolves and repeats until the jet stream reaches its weakest position in the summer”.
Ok so what does this mean?
The weather repeats. Not exactly the same every cycle, but weather that occurs on a specific date will return with similar result the next cycle. Once you learn the cycle length and the path of the storms, you can make a prediction for future weather. Here are a few examples from last year.
Breckenridge Recurring Storm #5
Cycle 1 November 26/27 7″
Cycle 2 January 23-24 16″
Cycle 3 March 23-24 12″
Vail Recurring Storm #2
Cycle 1 October 10-13 10″
Cycle 2 December 8-11 9″
Cycle 3 February 4-7 27″
Big Sky Storm # 4
November 13-14 9″
January 10-11 17″
March 9-10 14″
By watching storms that occur in September, October and November we can accurately predict the rest of the ski season. So you know when to have planned time off from work and reserve your dates with your resort.
I was once like you, I’d pick a date, make my reservation and hope. Spinning the roulette wheel, hoping for powder. One out of 10 trips I would hit it. Then, about six years ago a local weather forecaster here in Kansas City explained that the weather cycles and repeats. I was skeptical, but the more I watched and followed the pattern I became convinced there was something to it. So I did my research, and planned my first ski trip using “The Pattern”. Sure enough I found powder, 8” and 6” right on schedule. I didn’t have a clue how I did it, I just used the cycle length and Whistler Blackcomb’s snowfall history to predict that it would happen again—and it did. More trips and years would follow. I hit powder about 70% of the time! How does it work? In September and October the weather pattern sets up and becomes entrenched throughout winter,spring and summer. A cycle length (number of days) gets established and the storms repeat each cycle. Last year cycle was about 59 days. Below are some examples. October 10th last year, I coined this storm the toilet bowl. This turned out to be the signature storm of last year’s pattern. It returned December 8, February 5, April 4, June 2, and July 31. The storm carried a 1-2 punch that would last a week. Below are some examples of the 500mb charts as the storm approached Colorado. Notice how similar the snapshots are. They are not exactly the same, there are several influences to the pattern that are different each cycle. The influences are the strength of ENSO, AO, NAO, MJO and PNA. Here’s a link that better explains the teleconnections from NOAA. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/aao.shtml
If any of you were lucky enough to be in Summit or Eagle last year before the roads closed, you were in the “Toilet Bowl”. I was at Beaver Creek when they closed the roads. Had to drive back to Breckenridge the back way, pretty dicey.
This is what is possible. It’s not perfect, but you can dramatically raise your odds than just throwing a dart at the calendar.!