A stronger-than-normal Bermuda high-pressure system is contributing to the lack of relative humidity in the middle atmosphere across the tropical/subtropical North Atlantic basin. The lack of RH in the mid-level atmosphere is well-correlated to lack of tropical cyclone activity since Elsa earlier this month.

Currently, an unusually warm SSTA pattern persists across the central and east Atlantic tropics. The anomalous warm SSTA represents buoyant low-level atmosphere moisture. The IMME (model) forecasts the warm SSTA to surge westward into the northern coast of South America as a La Nina pattern (also) develops by October. The combination of the two SSTA regimes should yield a much-needed wet climate for Brazil.

El Nino southern oscillation (ENSO) is often the most relied upon climate signal to project seasonal climate patterns all around the globe. ENSO is certainly important especially when stronger El Nino or La Nina are present. However, regional sea surface temperature anomaly (SSTA) patterns such as the Pacific decadal oscillation (PDO), Atlantic multi-decadal oscillation (AMO), Indian Ocean Dipole (IOD), northeast Pacific “warm blob” and North Atlantic Warm Hole (NAWH) are increasingly relevant to generating climate forecasts.

Due to implications of potential flash drought in the Great Lakes/eastern Ohio Valley to Northeast U.S. by the Evaporative Drought Demand Index (EDDI) Climate Impact Company is issuing a drought watch for the northeast quadrant of the U.S.