some years, the pacific ocean high-pressure zone is weak, and the high-pressure zone in the sea of okhotsks strong. when this happens, a cold air mass will move south, cold winds will blow into tohoku from the north, and we get the phenomenon known as yamase. when yamase occurs, temperatures stay below 20 degrees celsius, even in august. cold temperatures can last for a long time-- as long as ten days or even a month. when this happens, the rice kernels don't form. narrator: ly is crucl to devopment of the rice keels-- it iduring this time the fin the seasonlant. that they're fng inside thetalks. dunghis period kobayashi checks his fields three times a day. he is constant fine-tuningthed to correspond to changes in. since the temperature water iof the wateraises e lt will be warmer than the air, the deeper water protects the delicate ears from the cold air. in 1993, the cold weather brought to northern japan by yamase continued into august. damage to the rice crop was severe. in some regions, the harvest was a total loss. in september of that year, government offials came to rokune to chec