12:50 AM CDT | August 18, 2017
Tropical Storm Harvey is nearing the Windward Islands with maximum winds of 40 MPH. Its wind field is fairly small right now, but additional strengthening is expected over the next few days. Weather models have been struggling with these waves in the Atlantic. The issue with most has been that they are too slow with the organization that is occurring.
Believe it or not, this can also cause an issue with its track. Weak tropical cyclones are influenced by steering winds in the lower-atmosphere. As the cyclone strengthens and deepens, it is influenced by winds higher up.
If a weather model is off on a system’s intensity, it can throw off its forecast track as well. Take a look at two recent graphics from the CIMSS website. The first is the mean steering winds for a weak cyclone – tropical depression to weak tropical storm. The second shows the steering winds for a moderate tropical cyclone – strong tropical storm to category two hurricane. Notice the difference. This is why it is important to compare the weather models to what is actually happening. They are a helpful tool, but if junk goes in, junk comes out.
Behind Harvey, we have Invest 92L which is likely to develop. We could see “Potential Tropical Cyclone 10” later today or this weekend. 92L is likely to take a more northerly track than Harvey, but it is still too early to say where it will end up. Continue to keep an eye on the forecast, and if you have friends or family near the Gulf Coast or East Coast, please make sure they are aware. It continues to look like a busy end to August for the Western Atlantic and Gulf of Mexico. You can get the latest here, on Facebook, and the Google Play app!