Yamase, a cool easterly wind system, often blows over the Pacific Coast of Northeast Japan in early summer. Temperature distributions under it were discussed in some cases in Aomori Prefecture, northernmost part of the main land of Japan.
Among days of June and July (1908-1970), 105 days, in which Yamase was observed at Hachinohe Observatory, were used as examples.
In terms of analysis of air temperatures at 38 meteorological stations in this prefecture (Fig. 1), areal boundaries which divide areas directly influenced by Yamase from others are found. They run in forms of remarkable discontinuities on temperature distributions (Figs. 2, 3, 4 and 5) along hills athwart this wind and at places where it meets with other local wind systems from inland as well.
Based on these boundaries this prefecture is divided into three sections as seen in Fig. 6.