Flash droughts in the Caribbean

Caribbean Islands, which often receive daily rainfall, are especially vulnerable to flash droughts . Credit: U.S. State Department

While much research has focused on flash droughts in various regions, tropical environments have largely remained understudied. This oversight is significant because these areas are accustomed to frequent, near-daily precipitation, making them susceptible to sudden and severe drying. Nowhere is this vulnerability more evident than in the Caribbean. With many islands having limited access to freshwater reserves, this leaves them exceptionally vulnerable when rapid drying events occur. In the face of a flash drought, these islands often struggle to meet the water demands of their populations, agricultural sectors, and ecosystems.

In a new Journal of Hydrometeorology, authors Craig Ramseyer and Paul Miller fill the gap in understanding tropical flash droughts by examining their prevalence in the pan-Caribbean region using the Evaporative Demand Drought Index (EDDI). The EDDI identifies instances of widespread flash drought “outbreaks” in which substantial portions of the Caribbean experience rapid drying over a 15-day period and sustain this condition for an additional 15 days.