There is a lot to discuss regarding the future track and intensity of 99L as it could affect literally millions of people from the Caribbean to the U.S. East Coast.
First, the current situation. Right now, 99L is rather disorganized over the Caribbean Sea but is forecast by all of the global computer models to gradually organize and become a tropical cyclone within the next two or three days. It looks like Jamaica, eastern Cuba and Hispaniola could be in line for quite a bit of rain and wind by the middle of next week.
By Thursday, the GFS places a strengthening tropical cyclone over eastern Cuba with heavy rains spreading across the southeast Bahamas. Water temps in this region are still very warm and it is possible that we could be looking at a rather strong tropical storm by this point as most of the guidance suggests steady strengthening.
By late next week, most of the reliable model output suggests a track in to the northern Bahamas, not too far off the Florida east coast. This is important because there is likely to be an indirect impact to Florida because of the presence of this system and a high pressure area to its north. It appears that a fairly strong surface high will move off the Northeast coast late next week and it could do two things. First, the high pressure north, coupled with the deepening low pressure off of Florida, will create quite a strong pressure gradient. This means the winds will be quite stiff out of the northeast for a good deal of the east side of Florida. So at the very least, rough surf and rip currents are a good bet towards the end of the week for Florida.
The other issue is that this high could act to block what would presumably be “Sandy” from turning out to sea. In fact, both the GFS and the ECMWF show this scenario and take what looks strong enough to be a hurricane right in to the East Coast of the U.S. somewhere north of Cape Hatteras. Sea surface temperatures in this region are running a couple of degrees above normal for this time of year and have not been disturbed by a previous hurricane earlier in the season. We are going to have to watch the evolution of this pattern very carefully over the next few days. What looked like a sure bet to send “Sandy” out to sea is no longer such a home run, so to speak. This could mean that people from the Caribbean Sea to Florida and eventually the East Coast have to deal with some degree of a tropical system over the next week or so. Interests in Jamaica, Cuba, Hispaniola and the Bahamas need to watch this system closely. We’ll see how things progress and can focus more on potential U.S. impacts as we get in to next week. For now, it looks like a slow process for 99L to develop but once it does, there is potential for it to impact a lot of people over a wide geographic swath.
I’ll post more here about 99L tomorrow morning. I also will be posting regular video blogs to our iPhone app which is a great way to visually understand what I discuss here in the blog posts. If you don’t have the app, there is no better time to get it. We’ve recently added our own tracking maps and of course have the exclusive in-field weather data, live web cams and video blogs should a landfall take place.