Rainfall was scarce across much of the country in the month of September, pushing the eastern and southern thirds of the country into drought conditions. IMERG, the Integrated Multi-satellitE Retrievals for GPM, is a unified satellite precipitation product produced by NASA to estimate surface precipitation over most of the globe.

The intertropical convergence zone or “ITCZ” roughly forms a band that circumnavigates the Earth near the Equator where the northeast trade winds in the Northern Hemisphere converge with the southeast trade winds in the Southern Hemisphere. Sailors have often referred to it as the “doldrums” due to its generally light winds. Yet, the ITCZ is an important part of the global circulation as it forms the ascending branch of the Hadley circulation. This is ultimately driven by incoming solar radiation, which peaks near the Equator. This warms the air and the ocean, causing warm buoyant air to rise...

Latent heating (LH) arises predominantly from the release of heat associated with the condensation of water vapor into cloud droplets in clouds with active updrafts. Other sources of LH include ice deposition and freezing, while evaporation, melting and sublimation induce cooling, but condensation is the dominant heating term. Like a hot-air balloon, LH can keep air parcels warmer than their surrounding environment and therefore rising. On a large scale, LH is responsible for driving the ascending branch of the Hadley Circulation. LH is also an important component in the dynamics of a regional...