Monday 17 February 2020

No seasonal snowpack this year

Niigata City and indeed much of Japan just had the warmest January since records began in 1882. The average January temperature during 1981-2010 was 2.4 degrees Celsius, while this year it was 5.2 degrees Celsius. The second warmest January on record was in 2007 with 4.9 degrees Celsius. Globally, January 2020 was also the warmest on record.

Location of snow lysimeter in larch stand near gauging station

Some snowfall occurred in early February, but most of that has already melted away at the low elevations. In 20 years of snow survey at Takiya River basin, this is the first time that there has not been a seasonal snowpack at low or even medium elevations (0-600m).

Stage about 0.8m at the gauging station

Strong warm winds and rainfall (8 m/s, 11.7 degrees Celsius, 51 mm) combined to produce rain-on-snow conditions and high runoff with some suspended sediment load. Even high elevations above 500m only retain patchy snow cover.

Forest harvesting activity near the gauging station (Japanese cedar, "Sugi")

Small mountain shrine about 2 km upstream of the gauging station