Hurricane season back to life with two systems brewing
Tropical Storms Josephine and Kyle dissipated over the weekend, leaving the Atlantic Ocean free of storms. But that may not be the case for long. A pair of tropical waves with increasing odds of development are traversing the ocean to start off the work week, preluding a period of anticipated intense activity that may last into September.
The National Hurricane Center estimates one of the waves has about a 50/50 shot of developing into a tropical depression or named storm in the coming five days, while the other was assigned a 60% chance. Both disturbances are in positions that, if they strengthen, could result in eventual impacts to land.
If one or both of these systems earn names, the next two on the list of storms are: Laura and Marco.
The forthcoming bout of activity has been anticipated for weeks due to the incipient overlap of several key weather systems that will enhance rising motion over the Atlantic. That will foster hurricane development and make tropical cyclones more likely.
The 2020 Atlantic hurricane season has been a record busy one, with 11 storms forming. That’s an average season’s worth of cyclones. Among the storms have been the earliest C, E, F, G, H, I, J and K storms on record.
None have been particularly impressive categorically, and most systems have been relatively short-lived. That is likely to change though as we head into the heart of the Atlantic hurricane season.
Part of the reason for the enhancement in activity? A convectively coupled Kelvin wave. It’s certainly a mouthful, but the underlying concept is simple: It’s a large, overturning circulation in the atmosphere with rising air on one side and sinking air on the other.
Where the air sinks, hurricane chances are less. But where the air rises, an enhancement in tropical cyclone activity is likely.
That wave is scheduled to team up with a similar feature that will enhance storminess known as the Madden-Julian Oscillation, or MJO. Together, they will work to kindle any fledgling attempts at tropical cyclone development over the Atlantic in the coming weeks.
Meanwhile, anomalously warm waters over virtually the entire Atlantic basin, due in large part to human-induced climate change, will amplify the threat of a higher-end storm. Warmer waters increase the potential strength of hurricanes and the amount of rain they can produce.
Warm ocean waters also can boost the odds of rapid intensification, which can be especially problematic in the hours preceding a hurricane’s landfall. Meteorologists still struggle to adequately predict rapid intensification in advance.
The period of heightened activity, which could at times feature multiple hurricanes simultaneously across the Atlantic, is set to last several weeks and could bring us to the climatological peak of hurricane season in mid-September.