The overnight runs of the various computer models did not really get us any closer to “knowing” the outcome of what becomes of 99L.
As it stands now, the tropical wave continues to slowly get better organized over the warm waters of the extreme southwest Atlantic – but I emphasize the word “slowly”. It seems that strong upper level winds are continuing over the system, preventing the thunderstorms from persisting and wrapping around the broad area of low pressure situated just north of eastern Hispaniola.
Despite the lack of organization, strong winds are being observed in the convection that itself is well removed from the low level center (poorly defined low level center). In addition, heavy rain is spreading over portions of Hispaniola and this is cause for great concern due to the risk of flash floods and mudslides. Remember, there are some fairly tall mountains in the region and tropical rain fall can lead to lethal flooding and tremendous damage.
The wave of low pressure is forecast to continue moving off to the west-northwest today and tomorrow, reaching the southeast Bahamas during that time frame. From there, it is likely to track through the Bahamas and toward Florida this weekend.
Now the tricky part: how strong does this system get – if at all? My answer: I honestly don’t know. The computer guidance is very confusing with the majority of the U.S. generated models, such as the GFS and the hurricane-specific HWRF model both showing little to no development, at least not in the short term. It is interesting to note that the HWRF, which stands for Hurricane Weather Research Forecast, is now indicating significant strengthening in the eastern Gulf of Mexico, around days 4 and 5. I am skeptical since that same model has had a very difficult time developing 99L much at all the past day or so.
On the other hand, consistency has been the rule for the much talked about ECMWF model or Euro. It has not strayed from its forecast of a possible hurricane impacting south Florida later this weekend. From there, it goes on to strengthen and make landfall up near the Big Bend area as a formidable hurricane. Needless to say, this is quite concerning but exactly how much stock do we put in to it? I just don’t know what to make of all this right now. On the one hand, the remarkable run to run track record of the Euro makes me think it could have the correct overall solution – that being a potential hurricane for some portion of Florida in the coming days. Conversely, the lack of development seen by the GFS and the waffling of the HWRF model for track and intensity makes me wonder: will anything happen at all?
All of this is not good for the public and the perception of how hurricane forecasting is “supposed” to be. Usually we don’t keep waiting and waiting just to see if a system will develop. The advantage, if you’re going to have to deal with a hurricane, is knowing it is coming in the first place. The “what if” scenario here is a little unsettling.
Let’s suppose that 99L does indeed wait until 24 hours before landfall in south Florida, assuming it does in fact take a path in that direction. If it were to quickly intensify over the very warm waters, how fast would it ramp up? Could it become a hurricane rapidly? Yes it could. We’ve seen it before but it’s been a while. Katrina in 2005 was on a fairly steady pace to strengthen as it approached SE Florida from the Bahamas but we at least knew it was a strong possibility well ahead of time. People will react better to a named storm or a hurricane headed their way than to a tropical wave. At least that’s my thought on the matter. This is a tough situation as the longer we wait, the less time there is to get ready if the need arises. While we would all like to wish that everyone along the coast was prepared anyway, we know the reality and it makes for quite the sitting duck in situations like this.
The afternoon runs of the various models (actually based on morning data) will be quite telling – or not. Questions about whether or not the GFS steps it up and develops 99L may be answered. What if it has the answer already and nothing much is going to happen to begin with? Maybe if the Euro suddenly shows little to no development we can at least say, ok, two major global models now show a low impact event. We will just have to wait and see. Either we know more or are stuck with dueling models once again.
I will post more here this afternoon including my daily video discussion.
M. Sudduth 8:50 AM ET Aug 25