Abstract

The problem of rainfall over Egypt has been investigated. The distribution of annual amounts of rainfall is given and remarkable variations along the Mediterranean coast are discussed. Winter is the season of rain in the north of Egypt, but in the south (Upper Egypt), two main seasons are found, namely, May and October. The diurnal variation of rain of two coastal stations and one inland station is given and discussed. Warm-front rain practically does not occur, and cold-front rain forms only a small proportion of the total amount and occasions of rain. Most rainfall is found to be non-frontal and associated with upper cold troughs (or lows) which seem to play an important role, not only in Egypt, but all over the Eastern Mediterranean. Rainy situations in each season are discussed. It is found that, in winter, rain is generally associated with Mediterranean depressions, but when these depressions are not associated with upper cold troughs, they move quickly with very little precipitation. In the spring and autumn, however, rain is usually associated with small desert lows with cold upper lows or troughs.