Orographic precipitation influences water resources, flooding and landslides, regional climates, and global water budgets. Progress has also been made on thermally driven island convection in the tropics. In contrast, the Dominica Experiment (DOMEX) was designed to study orographic precipitation in the tropics with cumulus triggering by forced ascent in unblocked flow. While many larger tropical islands experience a diurnal cycle in precipitation driven by solar heating, this type of modulation is very small on Dominica. On normal to strong tradewind days, it seems that mechanically forced ascent rather than solar heating triggers the convection and precipitation. The King Air flight pattern consisted of an upstream sounding and six horizontal legs. In the weak wind case, warm thermal boundary layer flow is pushed westward to the vicinity of leg 4 by the prevailing winds. Judging from the latent heat fluxes, the weak wind convection is at least as strong as the strong wind convection.
Smith, R.B.; Minder, J.R.; Nugent, A.D.; Storelvmo, T.; Kirshbaum, D.J.; Warren, R.; Lareau, N.; E Palany, P.; James, A.; and French, Jeff (2012). "Orographic Precipitation in the Tropics: The Dominica Experiment." Bulletin of the American Meteorological Society 93.10, 1567-1579.