Exciting weekend with what was likely the storm of the 17/18 winter hammering CA. The results so far have been impressive for the Lake Tahoe region and Mammoth. Data still incoming for Southern California and the Kern drainage. Both locations picked up 3 to 6 feet of snow, with unofficial reports of Mammoth picking up even more at the top. This storm had improved fetch, which means it picked up more moisture and delivered a refreshing bump in the snow water content. It lost quite a bit of its punch as it rounded Point Conception, so we will see if our drainage will report something close to those numbers. One can hope. We did get a sneak peak for the general snowpack for Northern, Central and Southern California, which is shown below. These readings get updated Monday through Friday. The storm kicked off on Thursday and by Friday Southern California had seen a bump from 19% to 25% for this date in time. This upcoming Monday will be exciting to see how much it has further bumped up, especially considering that Friday was when it was coming down the hardest.
This brings up a fascinating question: How close does the Kern drainage match the Southern California snowpack average? Is the average a gross simplification of what the Kern drainage actually looks like? Let’s dive into the data.
Upper Tyndall Creek is a single snow sensor for the Kern drainage. It’s an important one as it’s the highest at 11,400 feet. For reference, the closest town to it is Lone Pine. Over some coffee yesterday morning I recorded it’s adjusted snow water content for January 1, February 1, March 1 and April 1. I went back 21 years to 1997. I then went over April 1 snowpack averages for the same four dates going back as far as I could, to 2002. (Not sure why the data wouldn’t let me go further, I emailed CDEC about it.) I then plotted the data and it gave me the following.
It’s easy to see there’s a close correlation there. Of note, the two far-right outliers on the x-axis, we had the Kern drainage reporting much higher snowpack percentages than what was reported in the Southern California averages, one of which was last season of the 16/17 winter.
The correlation came out to 96.4%, which was much closer than I had anticipated before I saw it graphed, especially being just a single snow sensor. To find a single snow sensor that hit that close is impressive. What would come next is for me to graph each sensor in the Kern drainage and compare it, but I don’t have time for that.
Another interesting point with the Upper Tyndall Creek gauge is that it’s April 1 average for snow water content is 27.7 inches. This data goes back to 1970, which I didn’t dig into as far, stopping at 1997. From 1997 to today, that average is now 20.24 inches, which is a 26.93% decrease. Were the recent drought years that big of a hammering to change the average that significantly? Omitting 2012, 2013, 2014, and 2015 (the deepest years of the drought) the average rose slightly to 22.46 inches, which indicates that no, it hasn’t been just our recent events that have brought this number down.