This past week is a good case study as to why you cannot always buy into what the various forecasts models plot out in the way of tropical cyclones. I think in this case the models have it about 1/2 right.
If you have been keeping track, this pesky area of convection in the Caribbean Sea (tagged Invest 94L) has been gradually meandering to the north. If you have looked at any of the model outputs, there has been consensus in 2 directions: either northwest into the Gulf, or northeast into the Atlantic. My forecast for the past week has been a tendency to the northeast with time.
But, even accurately trying to predict where a tropical low may be head requires a little more investigating. First you have to understand model tendencies and biases to interpret some of the data correctly. Secondly, you have to research the current atmospheric environment to correctly try and forecast strength and direction. If you just glance at the model output, you would say Invest 94L is for sure heading into the Gulf, because the majority of the models say so! In fact, glancing at the wind analysis chart below, you would see, indeed, a strong southeast high pressure ridge would direct this low-level circulation to the Gulf of Mexico.
And, this is where our models get it about 1/2 right! Yes, the low-level swirl may be heading into the Gulf, but the overall upper wind pattern is one of deflection and with a system that is in developmental stage, usually the upper winds quickly dictate life or death to a tropical low. So, for this Caribbean low, the strong upper level winds are tearing up any chance of immediate development. Watch the water vapor animation below and you can see how the whole environment around our suspect low is very hostile!
I think the models for Invest 94L are having a tough time figuring out and discerning the low-level center drifting northwest and the mid-level center that is getting sheared east. This is very common in early-season systems and ones that are in the development stages. As we have stated before, you need more than warm water and a mass of clouds to create a tropical cyclone. It takes a combination of perfect environmental conditions. And in today’s case study, I have provided you a good example with the meteorology to back it up.
What’s your take?