In these days of complex computer-graphed simulations and space-assisted data mining, hurricane prediction has steadily approached something like a real, reliable science. Usually, scientists can at least guess with some decent certainty what a hurricane will do in the next couple of days, if not four or five days out.
Tropical Storm Erika, however, is making all the hurricane models stumble like Burt Reynolds on Celebrity Jeopardy. In a short couple of days, Erika could be pounding Miami as a significant hurricane — or it could all but fizzle out today over the towering peaks of Hispaniola.
"There's still a lot of uncertainty with the track and the intensity," Danielle Banks, a meteorologist for the Weather Channel, told NBC this morning.
Here's what NOAA knows for sure as of 5 a.m. today: Erika is a loosely organized tropical system with 50 mph winds and is heading north/northwest at 17 mph toward Puerto Rico and then Hispaniola. Puerto Rico could see four to eight inches of rain, with as much as a foot in some areas. Dominica already got nailed with severe flooding from the system:
But the big challenge for the computer models is that Erika is fighting really high wind shear and will also likely encounter the mountains of Haiti and the Dominican Republic as it heads northwest. No one really knows how well it will survive those two hurricane-killing forces.
If Erika survives that gauntlet, we could see a serious hurricane blow up.
"If Erika makes it into the Bahamas relatively intact — and that remains a very big 'if' — we could be dealing with it for days to come," Bob Henson writes on the Weather Underground. "Conditions over the Bahamas will be quite favorable for strengthening."
Weirdest of all, though, is that South Florida's biggest threat might be if Erika is seriously weakened by passing over Hispaniola. That weaker storm, then, would be much more likely to steer straight north and wreak havoc on Miami. A stronger Erika that avoids Hispaniola, by contrast, would be more likely to continue strengthening but also steer out toward sea.
"A weaker Erika would be steered more by lower-level easterly flow, perhaps moving over or near Hispaniola and on toward South Florida and up the peninsula as little more than a tropical storm," Henson writes. "A stronger system would be more inclined to stay offshore, perhaps heading north through the Bahamas and toward the Carolinas as a Category 1 or stronger hurricane."
So which will it be? No one knows yet. If you live in Miami, it's still a very good time to — calmly, sanely — make sure you're prepared for a hurricane to hit Sunday or Monday.