Once again this week, much of East Texas will sit beneath a haze of dust that has traveled across the Atlantic Ocean from the Sahara Desert. Unlike last Friday, it won't be quite as intense, but anyone with allergies or asthma will certainly feel the effects.
This time of year, sand drifting on winds aloft thousands of miles is not uncommon. However, this year has been some of the strongest plumes we have seen in decades. There may, however, be a slight silver lining: Saharan dust does tend to inhibit the development of hurricanes across the Atlantic Basin. It might be good to understand exactly why.
An environment that is ripe for a tropical storm is warm, calm and loaded with moisture. Things like deep pockets of warm ocean water mixed with moisture in the atmosphere and a lack of turbulent wind sheer make for the perfect ingredients.
The plumes of sand that blow off of the Sahara inhibit two of those ingredients. First, they block out sunshine, preventing ocean surface temperatures from heating up and fueling storms at their core. A quick look at sea surface temperatures shows that they are still quite warm across the heart of the Atlantic, but the recent dust dropped them about a degree, which is significant considering they were a bit more than one degree above normal for this time a year.
While they will certainly go up again, another round of the haze coming in a few weeks will again help to keep those temperatures down slightly before the heart of hurricane season heats up.
The other direct inhibitor to storm development is the dry air the dust brings. It can be quite difficult for any storms to form in and around areas covered in the dust and that certainly includes hurricanes.
Sadly, this doesn't mean we will see fewer hurricanes this year. Scientists are still predicting a busy year in the Atlantic, but every little bit helps. And while the dust may not be pleasant when it is sitting over a hot, humid Houston, more over the Atlantic is a good thing when it comes to hurricanes.