As Isaac tries to gain organization today, its future track remains a big question mark. It seems fairly certain that over the next day or so that the storm will pass over parts of Hispaniola and Cuba. It’s what happens after that part of the track forecast that has huge implications for Florida.
As you may recall, the computer model guidance has been shifting west over the past couple of days and the threat of a significant hurricane landfall along the central Gulf Coast seemed to be growing. This westward trend has apparently come to a halt today and now the threat to southeast Florida and the peninsula as a whole is back in play.
The key elements are a trough and ridge. The ridge is a large area of high pressure situated over the western Atlantic that acts to push on Isaac like a large water balloon. The trough is like a wedge that comes in and is stronger than the water balloon and pushes on it, creating a space for Isaac to move through. If the ridge is strong enough and resists the trough, then Isaac tracks farther to the west. If the trough is strong enough, then Isaac takes that weakness in the atmosphere and comes in to the Florida peninsula. It is not out of the question that the trough energy would be enough to pull Isaac up to the east of Florida either though nothing right now shows that happening. We did see with Irene last year how much the five day forecast can change, even day to day.
The U.S. based GFS or Global Forecast System model in its most recent run shows Isaac bearing down on southeast Florida in about 48 hours and beyond. This is in response to a clear break in the ridge of high pressure over the western Atlantic. While this development is excellent news for the central Gulf Coast, it brings back the possibility of hurricane conditions for the large population center of south Florida and the Keys. Furthermore, the GFS then brings Isaac up the west side of Florida and we all know what is going on next week in Tampa. It will be really interesting to see what the European model, aka ECMWF, shows on its run which will come out later this afternoon. The Euro model lead the charge for a westward track for several days in a row and has only recently begun to swing more east as it too sees a stronger digging by the trough over the eastern United States.
I know the public would like a perfect forecast with each storm but it’s just not possible yet. The NHC has an incredible amount of talent and modern computer guidance to utilize for each forecast cycle. But when we are talking three, four and five days out or more, there are just so many variables that can come and go, making each forecast a potential challenge. Fortunately for now, Isaac remains quite weak. That aspect of the forecast is also equally tough since rapid intensification can happen almost without warning. This is why people need to just be prepared and not waffle back and forth with the models or the forecasts. If you’re in the cone of uncertainty, then that means there is an uncertain amount of risk to you posed by that tropical entity. If a hurricane or tropical storm watch or warning is posted, then it’s time to act. Trying to second guess the guidance or the forecasts is never a good use of time. Just be ready in case Isaac tracks your way and keep in mind that it is a very large storm. This means the effects, wind, rain etc, will be impacting the areas affected well in advance of the center.
I am working on my video blog for our iPhone app now and will have it posted shortly. I will take a graphical, in-depth look at the latest GFS run and what the potential impacts could be for Florida this weekend and in to next week.
I will also be working on packing up equipment for a field mission to Florida where I will work with colleague Mike Watkins to cover Isaac’s impacts on the region. I may leave as early as this evening depending on the future forecast info from the NHC.
I would like to invite you to consider following along LIVE via our Client Services site. It is a subscription service that allows you to watch our progress live while being able to interact with us and other members via our own chat program. It is not open to the public so there are no trolls or troublemakers. Your subscription also gives you access to our expanded set of tracking maps, including our exclusive offering of Stormpulse maps. In addition, we set out our own live streaming video cam systems right in the heart of where the worst of the storm or hurricane is expected. This too is available, 100% ad free, to our subscribers. We have over 380 members from around the world, many from Florida. If you feel that having access to live coverage from a team who has over 15 years of experience in the field, then Client Services can serve you well. Click here to sign up today.
I’ll post another blog update early this evening or sooner if need be.