Regions of very warm ocean water known as marine heatwaves (MHW) are commonly linked to high pressure in the upper atmosphere which cause a dry and warmer than normal climate. MHW’s are present and quite strong off the U.S. West Coast and south of the Canadian Maritimes.

The month ahead outlook valid for August 2024 identifies above normal temperature risk for the entire U.S. particularly in the Great Basin and central Appalachians. The probabilistic rainfall outlook has increased confidence for a wet pattern in the Gulf States, Florida, and Carolinas. The wet zone is a candidate for land-falling tropical cyclones in August.

The latest collection of dynamic models forecasting the Nino34 SSTA through the end of 2024 continue to show evolution of weak La Nina although reliable forecasters ECMWF and Australia Bureau of Meteorology (ABOM) maintain neutral ENSO phase.

The North Africa climate pattern of the past 2-3 months is unusually hot and dry. Increasing trade winds south of intensifying subtropical high pressure is pushing Saharan Dust into the tropical/subtropical North Atlantic suppressing tropical cyclone development.