Local Winds:
Local winds in Akiyamago are characterized by small-scale and localized topographic effects, as well as specific regional atmospheric pressure and temperatures. These winds are particularly noticeable during adverse weather conditions and are influenced by valley terrains. In such cases, daily variations often occur due to thermal factors such as heating and cooling. Consequently, local winds caused by these geographic features are affected by meteorological conditions and frequently blow in different directions during the day and night. Winds associated with temperature differences between mountain slopes and valleys, known as mountain-valley winds, are also observed in Akiyamago. Winds like ‘oroshi’ (descending wind) and ‘dashi’ (gusting wind) are named after their local characteristics. Descending slope winds observed in Akiyamago primarily exhibit characteristics of Foehn winds. Local winds that arise due to thermal causes include sea-land breezes, which are influenced by temperature differences between the land and the sea.
Orographic Precipitation:
Akiyamago is also close to the Sea of Japan, leading to pronounced sea-land breezes caused by temperature differences between the mountains and the sea. This type of orographic precipitation is characterized by rapid adiabatic expansion as moist air currents rise along the mountain slopes, particularly in valleys, cooling the atmosphere and resulting in rainfall and snowfall. In these instances, the air flow, influenced by micro-terrain features such as valleys, leads to localized variations in precipitation with a close association between the direction of the slope and wind direction, especially in valley areas. Such sudden, intense rains are referred to as ‘showers.’
The “Akiyama Kikō: Travelogue” and “Hokketsu Seppu: Snow Chronicles of Hokuriku” document occurrences of hail, graupel, sleet, snow squalls, and ‘shiga’ (a type of mist), including notably rare illustrations of ‘snowflake diagrams’ and observations of precipitation (snowfall) phenomena through a microscope, which are seen in various locations.
Bokushi Suzuki observed and described graupel as grains or clumps of ice less than 5mm in diameter. These typically fall from cumulonimbus clouds during the winter when strong cold air masses flow through valley terrains from the ocean. Graupel usually forms from thunderclouds, where snow and cloud droplets combine within convective clouds to freeze. This phenomenon can also cause damage to crops. Moreover, ‘snow squalls,’ specific to this region on the Sea of Japan side, occur when seasonal winds carry snow clouds that fragment and deposit snow inland and on mountainous areas. These are also known as ‘fair-weather snow,’ characterized by alternating periods of falling and stopping.
The “Akiyama Kikō: Travelogue” and “Hokketsu Seppu: Snow Chronicles of Hokuriku” also record observations of hail, graupel, sleet, snow squalls, and ‘shiga’ (a type of mist), including extremely rare ‘snowflake diagrams’ and observations of precipitation (snowfall) phenomena through a microscope, seen in various places.