As mid-June draws near, there is a “hush” over the Atlantic basin, in part due to the presence of the Saharan Air Layer or SAL. This is not unusual.
NOAA defines SAL as a “mass of dry, dusty air that originates over the Sahara desert during the late spring, summer and early fall.” This very dry air helps to stabilize the atmosphere, limiting convection across the Tropical Atlantic Basin. Thus, the potential for any tropical wave to become organized is low. This thick layer of Saharan Dust, mixed with hostile upper level wind shear, means the tropics will remain dormant for the week ahead.
Saharan Dust can travel from Africa, across the Atlantic and even find its way to the United Sates. In fact, Saharan dust may be present over South Florida this week and, perhaps, aid in “drying out the atmosphere”-- resulting in limited thunderstorm development.
Saharan dust aside, forecast models show drier air moving over South Florida and the Keys this week. Models also show a ridge of high pressure building over the eastern United States.
Though this setup means temperatures likely get hotter, it is a welcome change from the stormy pattern that plagued Miami-Dade and Broward counties over the past week.
Also notable for southeast Florida is an expected shift in the steering flow. Last week, steering winds kept daily thunderstorms over metro Miami-Dade & Broward. This week, southeast to easterly steering flow should shift the focus of storms west of metro areas.
Finally and thankfully, the rain chance lowers and waterlogged communities in southeast Florida catch a much-needed break from drenching, flooding downpours.