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2015-2016 Ski Season Weather Analysis Compared to past 30 years: A summary of weather by Professional Local Weather Forecaster
Article by Kazuzo Niimi

This article (original article written in Japanese) was released April 2016.

Sequence of Snowfall and Snow Depth at Kabayama Observation Center in Kutchan

Sequence of Snowfall and Snow Depth at Kabayama Observation Center in Kutchan

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Figure 1.Data of Snow Depth and daily snowfall at the point near the base of Grand Hirafu Ski Resort.

The line graphs shows the sequence of snow depth in last five winters as well as 2008, which is one of the shortest snowfall years in ten years. The bar graph shows daily snowfall of last season. From the line graph we can see last season was the shortest snow depth season in the last five years. However, we had even less snow depth in years 2007, and 2008. The bar graph indicates we had reasonable snowfall almost every day after late December, although we did not have a huge snowfall day.

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Figure 2.Snow Depth in Kutchan Observation Center of Meteorological Agency

This is the data of snow depth in Kutchan town collected by the Meteorological Agency. This data is public and was taken from the website of the Meteorological Agency. In this figure, we see the average snow depth in the past 30 years compared to last year. (The purple line represents the last 30 years’ average and the green line represents last year.)
The two lines demonstrate that last season had a lower snow depth than normal in December 2015, but late December, the snow depth caught up quickly to the 30 year average. In January 2016, the snow depth was similar to the 30 year average. In February, we had warm days, therefore the snow depth decreased and remained far below average. However, cold air mass in late February increased snow depth to catch up the 30 year average and in some cases, reaching above average snow depth. Overall, trends of snow depth in the 15-16 season show less snow than normal. Only very short periods were above average.

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Figure 3.Temperature of ground level and upper air in 2015-2016 Season (Data of Meteorological Agency)

This is the data of daily maximum temperature at the point of Kutchan Observation Center and Upper-Air Weather Station at Sapporo. It is difficult to determine the difference of last winter’s trends compared to normal years. We can say up until mid-December, the temperature was higher than normal at both ground-level and upper air level. From late December to early February, the temperature was similar to the 30 year average. Mid-February until the end of the season had greater variance of temperature compared to earlier in the season.
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Table. Summary of 2015-2016 Season

Average Temperature and Snowfall
From this table, it is easy to see that 2015-2016 temperature was higher than the average and snowfall was less than the average. A remarkable point is that temperature of 500hPa was less than one degrees Celsius below average only in late February and late March. In other periods of the season, the temperature is one degree Celsius higher than the average. 850hPa, was not necessarily higher than normal, but 500hPa was higher than normal. In summary of the 2015-2016 season, the temperature at ground level was almost the same as the 30 year average, however, the cold air mass in the upper air was not strong, reducing the amount of snowfall. The temperature of Niseko in 2015-2016 was warmer than the average, but not much warmer than average. Another factor is that snow fall was less than normal due to the temperature of upper air mass was higher than normal.

Writer Profile: Kazuzo Niimi
Born in Kyoto, 1969, professional weather analyst living in Kabayama Kutchan. I really enjoy looking at snow, mountains, and clouds, or having an onsen. My hobbies are skiing and running. I am from out of Hokkaido, but entered the University in Hokkaido and was fascinated by the nature of Hokkaido. I have a passion for Professional Water Analysis. I worked for the Meteorolgical Agency for eleven years, however, my office was in Tokyo all the time. I decided to move to Niseko in Spring, 2006 to the base of Annupuri. I would like to provide more information about meteorology, particularly for the people who work in the natural environment.

Translated by Masayuki Ito & Leann Fay