I think you are right, but how does it affect our stormy weather? I think that is the unasked question. I'm not all that sure myself, but I'll try and see how close I can get:

SSTs This is the temperature of the ocean water. As troppical storms are heat driven, it seems that the more heat in the ocean (Water Temps) the more 'fuel' available for the storm. Somewhere about 80 degrees F seems to be the 'magic' number for the right fuel/air ration to start the engine. Higher temps mean more fuel and potentially stronger storms.

TUTT: Lets see, T)ropical - having to do with the tropics as opposed to the mid latitudes where we in the US mostly live.
U)pper - having to do with the top or highest levels more than down an the bottom of the ocean of air we tend to live in.
T)ropospheric - having to do with the troposphere, the air where we live, where the weather is and residing just below the Stratosphere...the first few miles of the atmosphere above sea level and last but not least:
T)rough - a lower than normal pressure for the upper regions of our troposphere.

What does the TUTT have to do with storms? Frankly I'm not totally sure, but I do know that storms require high pressures at high altitudes or it can't breathe and if it can't breathe, the engine won't start or stay running. Like stuffing a bananna into the tailpipe of a car....tends to limit perfommenc or even kill the engine. So, I would suspect a strong TUTT might inhibit storm genesis or limit activity somewhat while in the tropics.

Now, will a real met or someone who *really* knows tell us the real reason why these are important.