Rain does not fall at random but as a consequence of predictable synoptic processes. Typical local heat thunderstorms are rare. Cold fronts from the north are important whenever they occur. They are frequent in winter, when they bring rain and, occasionally, hail to the northern slopes and clear foehn weather to the southern slopes. Places of frontolysis are liable to heavy rains and flooding. Cold fronts in summer can contribute to the conversion of unsettled weather into bad weather. There is no monsoon in the original (Indian) sense of the term. The southern part of the Pacific coast experiences a trade wind from the Southern Hemisphere modified to blow from the southwest. Easterly flow governs most of the weather. Several types of disturbances are embedded in it. The slow ones normally stay in the Caribbean, so that easterly flow in Central America is characterized by much sunshine, which in summer is interspersed with showers or thunder showers. Cyclones are relatively frequent along both coasts but are rare over land. They range from ill-defined conditions to intense closed circulations. They can move slowly or even be stationary. It is probable that they are better defined aloft, but the inadequacy of the data makes further research impossible and cyclonic forecasting difficult. Hurricanes and Pacific temporals are special forms of cyclones. The secondary rainfall minimum in July-August occurs everywhere from Panama to Texas. In the southern part of the region it may be an indication of the movements of the intertropical convergence zone, but in most areas it is produced by intensity changes in the Bermuda anticyclone.