In order to gain background on the constraints on hurricane development from waves in the easterlies, a warm-core wave observed in the Caribbean was studied.

A composite based on the phase of the 30-60 day oscillation (referred to as the Madden-Julian Oscillation or MJO) is used to examine kinematic and thermodynamic fields over the equatorial western Pacific Ocean for the Northern Hemisphere winter seasons (1986-89).

Development of frontal disturbances is considered from a non-linear initial value point of view.