July is typically a transition month between less organized, homebrewed tropical systems and the long-track, powerful hurricanes of August and September. It’s in July – typically by mid to late July – that we more closely monitor tropical waves, disturbances rolling off Africa every 3 to 5 days that largely go unnoticed in June.
But this week may be giving us a sneak preview of what’s in store as the calendar turns the page. On Monday, the National Hurricane Center tagged the first tropical wave of the season for possible development.
The strong disturbance, accompanied by periodic storminess, is booking it to the west – at speeds above 25 mph – which in the short term will work against potential development. Forecast models indicate it’ll slow down as it enters the western Caribbean come Thursday into Friday, where it may link up with an area of enhanced background spin – the eastern arm of the Pacific monsoon trough – to have a brief shot at development.
It’s flying low for now, which does offer some protection from the big outbreak of Saharan dust and band of strong wind shear to its north, but entanglements with land as it nears Central America later this week may act as a speed bump to its potential development. For now, models are only lukewarm on development and high-pressure steering will keep it on a fast westward trajectory and away from the U.S.
This leading wave may, however, be a preview of what’s to follow behind it. Another strong tropical wave is set to roll off Africa by late week and move through the Atlantic into next week. Some of our more reliable forecast models suggest possible development as it heads generally in the direction of the Caribbean for mid next week.
In general, the upper-level pattern looks quite conducive to development east of the islands next week, with wind shear running well below average for the time of year.
We’ll have plenty of time to track this system as it takes shape, but those with interests in the Caribbean will want to check back on the forecast in the days ahead.
