Posted March 19, 3:16 pm MT 2:16pm PT
The California Drought is Over, but When Did We Know?
Now that there is a break in the action, I thought I would look back and try to figure out how we got here. This is possibly the greatest snow season on record, if we continue at this pace. In this blog, I look back through the posts and sift through them to figure out when we knew the switch was going to be flipped from drought to deluge.
First, a look at the month-by-month snow water equivalent maps, tale of the tape.
The above charts are a month-by-month comparison of snow water equivalent for the water year to date. Back in August and September, the pattern was set, but the jet stream hadn’t dropped down from Canada until the third week of October. That was really late. Usually, the jet stream drops by late September or the first week of October.
This video below shows what I am talking about. All of those storms hitting the Gulf of Alaska are the same storms we are having now. Different variables each cycle, but the same storms.
In you are new to FutureSnow, you are in for a surprise. The weather pattern is not chaos. It is actually organized. Storms cycle and repeat similar to the known oscillations that you may have heard of–Artic Oscillation (AO), Madden Julian Oscillation (MJO), and ENSO (El Nino Southern Oscillation). To learn more about the science behind our patent pending weather model and forecasting methodology, click here.
We knew that there were good storms, without any lengthily dry stretches, back in August. What we were waiting for, was to see how those storms tracked once we got to September and October. We waited and waited. Finally, on October 22nd, in Seattle, we started to fill in those answers.
On October 23rd at Big Sky, we got our first big storm, I wrote “No need to panic. The pattern systems (have) remained up in Canada, along with the jet stream that had not fully dropped until now.”
October 26th, blog post titled Is This La Nina Different? Yes, I wrote “it’s only 25 days into this water year, but it’s a good sign for Lake Tahoe and most of the west.” This is a pretty good post, I go through the winter forecast for NOAA. They were forecasting the drought to continue for California, Utah, and Colorado. We thought this was wrong. Of course, we had no idea what was to come.
Just 4 days later we had published Back-2-Back AR’s, where our tune was changing. I wrote: “All indications are that it (the pattern) is different. We have seen the October pattern flip from dry, the last two years, to average precipitation, admittedly a small sample size, but at FutureSnow, we will roll with it.”
Then We Knew
In the blog post titled It’s Tahoe’s Turn we ran the patent pending LRC model for the first time and it showed this.
It blew us away. Was it right, could it be right? All indications were saying yes, but 250% of average? That part had to be wrong–right? Well, it’s not far off. South of the Lake is at 226% of average.
Looking at the output from the model, we could see that the storms it predicted were aligned with our tried-and-true analog method for predicting storms.
There is a certain amount of pride that one gets when you put out a forecast, so far in advance, and it comes through. I have said several times, jokingly, to our competitor of ours, this forecast is the “greatest long-range forecast ever made.”
He never responds, but it’s true. Crazy but true. We are just a couple of guys in Kansas City that have figured out the mechanism that makes the weather. It is not chaos, the weather cycles and repeats. It is so fun that you, are in on this too!
Long-Range Forecast Chart
We are sitting around 93% accurate. That’s insane. Embarrassingly too good, but it’s real, it happened. Nobody will believe this, is the thought I have quite often. Even if you were very critical of the chart and called all amounts below 10 inches a bust, we would be 48 for 66, or 73%. The last couple of years we have had 88% and 89% in La Nina seasons. It makes sense that in an “El Nino like” season it would be easier to predict.
In the 4th Long Range Forecast the shortest lead time was 27 days with the longest being 64 days. Once we get a couple of cycles in, we dial in the forecast window. Meaning storms have only 24 hours tolerance, instead of 48. The storm must produce measurable snowfall, above 2″ within 24 hours of the projected date. There are going to be systems that are weakened, due to high pressure, or no moisture. I set the bar at 2 inches because orographic snowfall can occur.
Mountains can get upslope flow and cause the air to cool causing the water vapor to condense producing snow. Resorts can get an inch due to no storm at all. Maybe we should raise that bar to 5 inches next year. Something to think about. If you have any suggestions, I’d love to hear them.
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