HOUSTON – As I write this and check my pool water, it’s an amazing 88°! Totally ready for swimming, but the pool is a shallow body of water and easy to heat up when we’re having record heat! The Gulf of Mexico water is still hovering in the upper 70s to low 80s near shore, but 80° is that magical threshold where the water is warm enough to sustain tropical storms and hurricanes. And that number, which calculates to 26° Celsius, is abundant and goes even higher, to 28°C right now:
You’ll notice the warmest water is where the Gulf Loop is located -- that is warmer water from near the equator that travels through the Caribbean into the Gulf of Mexico -- eventually this water moves through the Florida Straits and up the Eastern Seaboard where it is known as the warm current of water called the Gulf Stream.
BUT, isn’t there always a but (?) ... the water can’t just be 80° at the surface but needs to be that warm 50 meters down or a little better than 150′ deep (165′ to be exact). As a storm moves along it cools the top layer of water, and so it will need warm water from below to replace it in order to maintain its fuel!
So we must look at where the warm water is and if it’s deep enough to support tropical formation. This is known at Tropical Cyclone Heat Potential. Take a look at yesterday’s TCHP:
The green colors indicate warm water 50 meters deep while the yellows to reds are even deeper. You’ll notice the highest heat potential corresponds to the above graphic showing the warmest surface temperatures, so no surprise!
What is alarming is that the library for these graphics goes back to 2005 and in not one year can I find a May 10th Tropical Heat Potential for the Gulf of Mexico as warm and extensive as right now. In fact, 2005 when there were 28 storms was not as warm yet even though it would reach 90° in the summer. Not 2008, the Ike year, or 2011, the drought year, or 2017, the Harvey year, or even the past five years were this warm at this time. This is THE warmest on record from what I could tell.
Here’s what it looked like this time last year, which you’ll remember was very busy:
Let’s be clear: Cherry-picking dates over a 17-year period is not going to set a forecast in stone, but it certainly tells me that the Gulf is as ripe as it ever was for tropical activity. The only thing stopping it right now is that the upper-level winds are still fairly strong and can tear up any developing storms, but those winds are forecast to calm down by the end of the month.
As we always say, be prepared! You can look at more on Tropical Heat Potential at NOAA’s website right here.