As of 1PM on August 21st, the National Hurricane Center is issuing advisories on Tropical Storm Laura and Tropical Depression #14. With both systems forecast to exist in the Gulf of Mexico simultaneously, I wanted to discuss both cyclones separately and also address what might occur if they emerge into the Gulf together.
Tropical Storm Laura
Tropical Storm Laura is forecast to be just off the Northern Gulf Coast on Wednesday morning with minimal hurricane strength. Looking at the projected path, Laura faces a long road through the islands and if the center of circulation interacts too much with the mountainous regions of Hispaniola or the eastern Cuba, severe disruptions in organization will occur. This would lead to extreme weakening and would make it difficult for Laura to rapidly intensify once it reaches the Gulf. How it transverses the islands will determine its ultimate fate. Latest models are trending further west with Laura’s track (see below).
Tropical Depression 14 (Soon to be Tropical Storm Marco)
TD 14 is forecast to cross the Yucatan Peninsula and enter the Gulf by late Sunday. There may a brief window for the system to strengthen into a hurricane before it encounters some strong upper level shear. Models are pointing to a Louisiana or Texas landfall. At this point, TD 14 appears to be the weaker of the 2 systems when approaching a Gulf Coast landfall.
The Fujiwhara Effect and What MIGHT Happen
Here’s a definition of The Fujiwhara Effect from the NWS:
“When two hurricanes spinning in the same direction pass close enough to each other, they begin an intense dance around their common center. If one hurricane is a lot stronger than the other, the smaller one will orbit it and eventually come crashing into its vortex to be absorbed. Two storms closer in strength can gravitate towards each other until they reach a common point and merge, or merely spin each other around for a while before shooting off on their own paths. In rare occasions, the effect is additive when the hurricanes come together, resulting in one larger storm instead of two smaller ones.”
So, how is this going to affect these 2 systems? Please keep in mind that the rest of this paragraph is pure speculation. First, I think it is highly unlikely that 2 hurricanes exist simultaneously in the Gulf at the same time. Yes, there have been 2 tropical systems in the Gulf at the same time (2 times in recorded history), but not with both being hurricanes. Also, I don’t think one system will be significantly stronger than the other, nor do I think there will be enough time over water, for one system to “eat” the other and become some sort of “megastorm”. What might be possible is that they do begin rotating around one another while in the Northern Gulf causing them to rake over the same areas, causing an almost double landfall in the exact same area. Also, the area between the 2 storms at landfall may see an uptick in tropical tornadoes due to an enhanced area of shear and helecity. Just thoughts and conjecture, It will be interesting to see how it all pans out. Go ahead and sign up for our Imminent Tornado Alerting System (ITAS) to give yourself added way of receiving warnings.