The use of average annual rainfall to derive estimates of orographic enhancement of frontal rain over England and Wales for different wind directions

摘要: A field of average annual enhancement, defined as the mean rainfall rate al inland sites minus over coast, has been derived for England and Wales. Past cases frontal rain associated with low-level winds from SW quadrant were analysed so to determine typical distribution intensity orographic enhancement. It is shown that these results are sensitive wind speed and, in particular, direction. Comparison suggest relationships between enhancement which used produce estimates may occur other directions. These fields can he combined radar observations sea short-period forecasts when it moves overland.