Monitoring of Heavy Rainfall and Snowfall
JMA′s Himawari-8/9 satellites observe areas in the vicinity of Japan every 2.5 minutes. The resulting data are used to monitor cumulonimbus clouds, which can cause heavy rain and snow.
Monitoring of Cumulonimbus Development
True Color Reproduction(TCR) imagery animation based on Himawari-8 observation conducted at 150-second intervals [MP4, 20 MB]
On 4 August 2016, clear atmospheric conditions brought by an anticyclone over western and northern parts of Japan were disrupted by a cold cyclone offshore of the Kii Peninsula (around center of the image), bringing extreme localized storms to western and eastern parts of the country. The image shows a series of convective clouds developing into cumulonimbus types in various locations. Hourly rainfall of 71.5 mm was recorded in Kanuma, Tochigi Prefecture.
Monitoring of Heavy Snow
True Color Reproduction(TCR) imagery animation based on Himawari-8 observation conducted at 10- minute intervals [MP4, 7 MB]
At 00:00 UTC on 14 January 2017, a developing cyclone (984 hPa) over eastern Japan was observed with east-northeastward movement, and cold air (below -12℃) was observed moving southward to western Japan at around 1,500 m above sea level. Satellite imagery from this period shows clouds forming near the coast of the continent and extending as streaks over wide areas of the Sea of Japan and the East China Sea. Convective cloud belts over western and central regions of the Sea of Japan are seen developing into cumulonimbus clouds over the Hokuriku region along the Sea of Japan, and snowfall exceeding 60 cm was recorded in Niigata Prefecture on the day.