ORLANDO, Fla. – A couple of weeks ago Beryl was breaking records while Chris quickly developed and made landfall in Mexico.
So where did all of the tropical activity go, and does this put a wrench in the extremely active hurricane forecast that was issued before the season started?
Unfortunately, not so fast.
If there is ever a time to book a cruise during hurricane season, the middle of July is it. Now, it doesn’t always workout like this, but more often than not it does.
There are a few reasons for this.
Climatologically, we are transitioning from the homegrown storms of June and early July to the more long-track storms that roll off Africa and take days to cross the Atlantic.
Saharan dust also reaches its peak concentration, helping to gobble up prospective storms.
This year, there’s also a third thing, the Madden-Julian Oscillation or MJO, a phase that promotes Pacific development and fills the Atlantic side with sinking air to further deter storm development.
The MJO is a cluster of clouds and rain that moves across the globe every 30-60 days. It can enhance or suppress tropical activity, depending upon what part of the world its currently in.
Flipping the switch
The opposite will be true heading into August. We are, of course, heading into the climatological peak of hurricane season, which will naturally promote storm development. In addition, the MJO will move back into a more favorable position for tropical development.
Prolific rising motion, green in map below, will anchor itself over Africa.
This will help develop thunderstorm complexes that will eventually emerge into the Atlantic as tropical waves. Given abundant moisture and low shear, these will have the opportunity to develop.
Look for the last couple of days of July or early August for the African wave train to begin once again.
Once the storms undoubtedly get started again, the thing to watch for steering will be the placement of an upper-level ridge of high pressure.
It has been anchored over the Northeast, bringing them record heat. For the South, it means a more westerly track for tropical systems, meaning land would have a better chance to be threatened.