TS Ernesto certainly has improved its appearance since this time yesterday. As noted in the latest NHC discussion, appearances can be deceiving and Ernesto has, in fact, weakened some. I see this as probably temporary as the storm is pulling in air from South America and to some extent, the Caribbean islands to its north. Remember, tropical cyclones can be very sensitive to even the slightest changes in their environment. Once Ernesto gets to about the same longitude as Jamaica, it should start to intensify and become a hurricane.
It is very puzzling as to why the various global models do not “see” Ernesto very well. This is called initialization and the models are not initializing the storm very well. I have read quite a bit on various message boards about how this could be throwing the future track forecast off. The logic is that if the models do not see the storm at the beginning of the run, then how can they predict where it will go later in the run? Let’s look at it from an entirely different point of view.
Forget that Ernesto is even in the picture. Then look at the computer models. I’ll take the GFS as an example. What does the large scale pattern look like three to five days down the road? Is there going to be a weakness in the big high pressure area over the Gulf of Mexico that would allow the would-be hurricane to turn more to the north? Not really. There seems to be just enough subtropical ridge nosing in from the Atlantic, across the eastern Gulf, to keep Ernesto on a WNW track towards the Yucatan and then in to mainland Mexico. So whether or not Ernesto is strong, weak, picked up in the models or not, I do not think it matters. The steering pattern strongly suggests that it will not directly impact the U.S. down the road. The only possibility that I see right now is south Texas but even that is a long shot in my opinion. So all this talk about the models not initializing the storm and thus not trusting them is non-sense to me. The trend has been more west with the tracks and since we are not quite in to the time of the season when deep troughs dig in to the Lower 48, I just don’t see a way for Ernesto to hit the U.S. Can there be a sweeping change coming up? I suppose so, you never say never but track forecasts are getting pretty good these days so I wouldn’t count on there being any big changes over the coming days.
With all that being said, let’s focus on the Yucatan now. Obviously with a hurricane aimed at that location, people need to be aware and ready to take action. Ernesto has to cross some fairly high ocean heat content (see graphic where the track is plotted on the current TCHP map). However, it is not forecast to go over the highest values, none the less, the western Caribbean is notorious for creating strong hurricanes and I urge people along the eastern side of the Yucatan from Belize to Cancun to watch this system carefully. It has the potential to be a serious hurricane for the region next week.
Beyond the Yucatan, as I said, the data suggests another landfall in mainland Mexico, south of Texas. We’ll worry about that later since it is still perhaps over a week away.
Next we have Florence out in the tropical Atlantic. This will be an interesting feature to track but should not pose a problem for land areas. It is already at a fairly high latitude and developed well east in the Atlantic, meaning that is destined to head out to sea. While there are certainly instances when long track hurricanes have made it all the way across, most do not and Florence is likely to not break precedence here.
The other feature to watch is just off the Florida coast. I think the only issue here is the increase in showers and thunderstorms for boating and beach interests. Otherwise, ignore it, nothing will come of it that will have any great consequence on your weekend plans.
I’ll post a video blog detailing Ernesto’s future in our HurricaneTrack app for iPhone shortly with another full post here this evening.