MIAMI (CBSMiami) — It’s not uncommon during hurricane season for there to be “outbreaks” of hurricanes followed by lulls and then more outbreaks. The periods of storms and no storms during the course of a season are often regulated by a large atmospheric wave known as the Madden Julian Oscillation (MJO, after Roland Madden and Paul Julian from research in the early 1970s).
This wave, as it moves slowly around the globe from west to east, enhances thunderstorm activity, especially over the tropics.
As the MJO approaches, rising currents in the atmosphere increase which helps increase thunderstorm activity. Once the wave passes, the air is mostly sinking and more resistant to storms.
When the MJO passes during hurricane season, tropical waves and disturbances are more likely to develop into hurricanes, especially if the background conditions of low shear and warm sea surface temperatures are present like they are this year.
As of mid-August, with the conditions already in place for an active season, passage of an MJO wave would likely contribute to a burst of hurricanes in the Atlantic Basin (Gulf of Mexico, Caribbean, and Atlantic Ocean).
Computer models, which do a fairly good job of predicting the position and future movement of the MJO, are indicating it will move out of the eastern Pacific and across the Atlantic toward the end of August and early into September. During this time, it is likely the first major hurricanes of the 2020 season will form and move westward across the Atlantic, Gulf, and Caribbean.
While it’s too early to tell where the storms would form or track, it’s not too early to make sure you and your family have a hurricane plan in place and ready to go. No one should ever be surprised in Florida by a hurricane in the late summer.
Craig Setzer is the Chief Meteorologist at CBS4 in Miami and has over a quarter century of experience in forecasting hurricanes and severe storms.