When WRF is used to simulate extreme precipitation in Henan Province the low level is the prevailing easterly wind Why does the precipitation area move eastward when the height of the western and nort

When the height of the western and northwestern mountains is increased, it leads to an increase in the topography of the region. This results in the creation of a barrier to the prevailing easterly wind, causing it to be lifted and cooled as it moves towards the mountains. The lifting process causes the air to expand and cool, leading to condensation and the formation of clouds. As a result, the precipitation at the foot of the Windward slope of the mountains decreases, while the precipitation in the east increases due to the formation of a rain shadow effect. The rain shadow effect occurs when the moisture-laden air rises and cools on the windward side of the mountain, causing precipitation, and then descends and warms on the leeward side, resulting in less precipitation. Therefore, the increase in the height of the western and northwestern mountains causes the precipitation area to move eastward, resulting in decreased precipitation at the foot of the Windward slope of the mountains and increased precipitation in the east