Records & Statistics Source:
For this article, I am using the stats reported by Berkeley's Central Sierra Snow Lab, which is located northwest of Lake Tahoe near Donner Summit, CA at an elevation of 6,894 feet. Other areas of the northern/central Sierra and at varying elevations may have seen slightly different numbers, especially higher in elevation where more snow tends to fall.
The data records available for daily and monthly precipitation and snowfall amounts start in the fall of 1970 when Berkeley took over monitoring the weather at the Snow Lab in Soda Springs, CA. That is the base period I will be using for the stats and graphs below. I will reference the 52-year average which is the 70/71 season through the 21/22 season.
We have annual snowfall records back to the 1800s when the railroad was in charge of keeping records. The new station manager at the Snow Lab is working to gather and digitalize the records prior to 1970, and we hope to be able to use those in our reports in the future.
October - February Stats:
I wrote articles at the end of January and February on the snowfall statistics for the season so far. You can find those here.
Northern Sierra Snowfall Stats as of January 20th, 2023 | OpenSnow
Northern Sierra Snowfall Stats as of February 28th, 2023 | OpenSnow
March started off with a big storm that dropped up to 3 feet of snow on the 1st of the month. The storms continued through the month with varying intensity and snowfall amounts.
In total, the Snow Lab recorded 219 inches of snow during the month, which is 302% of the 52-year average of 73 inches for the month of March.
That made March 2023 the snowiest March on record since at least 1970, and the 3rd snowiest month on record!
That makes two top 10 snowfall months this season, the first time we've had two in a season since 1982! The top 4 months all occurred during the last 6 seasons, with 5 of 10 occurring during that time frame as well.
Season-to-Date Snowfall Totals:
March's snowfall brought the season total to 715 inches, which is 213% of the 52-year average of 335 inches for Oct-Feb. That also makes this the highest Oct-Mar snowfall recorded since 1970, and likely the highest since the record 1951-52 season!
Here is a look at the snowfall by month compared to the 10, 20, 30, 40, and 52-year averages for each month. We have now seen 5 months in a row of above-average snowfall, which is the first time we've seen that since the 1982-83 season. That season actually saw above-average snowfall for 7 months in a row, or basically the whole season through May.
My total season snowfall graph goes back to 1950 as we have the annual numbers back to the 1800s. You can see that 1951-52 is by far the snowiest season on record with 813 inches recorded at the Snow Lab location. 2022-23 is now officially the snowiest season on record since 1970 and 2nd snowiest since 1950!
The snowfall through September 2023 will continue to be added to the 2022-23 season totals. We would need 99 inches of snowfall April-September to beat the snowiest season on record, which will be hard to do with the snowfall average for those months being only 48 inches.
Snowpack measures how much water content is sitting in the snow on the ground if you were to melt it down. On average our highest snowpack is seen around April 1st. As of 4/1/23, we were at 234% of the April 1st average, tied with 1952 for the highest on record for the date!
That's a lot of water being stored in the mountains that will fill the lakes and reservoirs as it melts through the summer months. Looking back to 2002 you can see that this season is easily the highest snowpack as a % of the average of the last 20+ years, and officially the highest in 70 years!
Most of the precipitation in March fell as snow at the Snow Lab as we had another month with very cold storms. The Snow Lab recorded nearly 23 inches of total precipitation in March, which is 245% of the 52-year average!
March was the 3rd wettest March on record despite being the snowiest March on record. That was due to more snow than rain and colder storms with higher snow:liquid ratios than average.
Season-to-Date Precipitation Totals:
When we add in the 22.99 inches of precipitation that fell during March, that gives us 81.1 inches for Oct-Mar precipitation, which is 158% of the 52-year average for the Snow Lab!
It also makes this the 4th wettest Oct-Mar period since at least 1970. Here is a look at the total precipitation amounts by month compared to the 10, 20, 30, 40, and 52-year averages for each month.
Both November and February had above-average snowfall from below-average precipitation, with Dec, Jan, & Mar all picking up both above-average precipitation and snowfall.
Snow vs Precipitation Variance:
We have seen colder-than-average storms most of the season since November, which is causing a large discrepancy in total precipitation vs total snowfall compared to their averages. I've been tracking this discrepancy for each season since 1970.
This season so far is the largest discrepancy on record, with a large positive variance between snowfall and precipitation of 55% (158% of average snowfall vs 213% of average precip). That happens during colder seasons like this when we have lower snow levels, higher snow ratios, and less rainfall than average throughout the winter season.
March was another cold month and ended up being 8.9 degrees below average for the month as measured for Truckee, CA!
That makes 5 months in a row of below-average temperatures, with the Nov-Mar average being 6 degrees below average! That lines up with the lower amount of rain and high snow ratios than average for the season, which helped to boost snowfall totals higher than they normally would be for 81+ inches of liquid.
The impressive precipitation amounts for March, added to the impressive season, dealt a final death blow to the drought for much of CA including the northern & central Sierra! The latest drought monitor shows that most of CA is now out of a drought, with only a few pockets of D1 in far northern and southern CA.
We will have to see what the rest of the snow and water season brings us through September 2023, but no matter what this season will be one to remember for a long time!