Hurricane Irma must be the most closely tracked hurricane in history. There seem to be dozens of US TV stations following it minute by minute. It’s been called a “nuclear” storm by the governor of Florida. And the point where it’s been due to make landfall is being called “ground zero”. Literally millions of people have been fleeing northward from southern Florida.
But do the weather forecasters really know where it’s going? Two or three days ago lots of the forecasts had Irma tracking up the east side of Florida (orange line below). It was supposed to perform a sharp turn right. And as time wore on, the expected turn got sharper and sharper. Now they’ve got the expected path tracking up the west side of Florida (red dotted line). That’s a 180 km shift westward in about 3 days. And even to get to do that, Irma is still going to have to take a pretty sharp turn right.
To my untutored eye, extrapolating Irma’s path in the direction it has actually been going, it looks like it’s going to track way west of Florida (yellow line), and could end up in Alabama. After all, a hurricane is a mass of air rolling across the surface of the Earth, not much different from a freewheeling truck.
Maybe I could use my orbital simulation model on it. Last night on the Smoky Drinky Bar, Brigitte was wondering if I could do that, and I was saying that I couldn’t. But in fact I can model the motion of a ball rolling over the surface of the Earth, in unimpeded motion. The thing that jumped the idea into focus this morning was when one of the breathless TV weather reporters spoke of a “closest approach” of Irma to Florida. That made Irma sound like one of my asteroids, which are usually making close approaches to the Earth.
I’m beginning to wonder whether the hurricane weather models they’re using are any better than their long-term climate models, which didn’t predict the past 18 – 20 year “pause” in global warming. And I’m wondering whether they’ve just evacuated millions of people from Florida when it wasn’t really necessary. And I’m wondering whether there’s going to be political storm breaking out when Irma misses Florida completely.
Which reminds me: did anyone predict that Hurricane Harvey would double back on its path, and so hang over Houston for much longer than it might ordinarily have done? I don’t remember anyone forecasting that.
I was writing a couple of days ago that these hurricanes made life a lot busier for everyone in their path, as they worked to clear up the mess and repair stuff after they’d passed by. It could well be that hurricane predictions are now also making life harder for anyone in their predicted paths. And that’s most likely going to be a lot more people than the number of people who are actually affected. From the Independent a day ago:
More than six million people – a quarter of the Florida’s population – have been ordered to evacuate.
That’s six million people who have been ordered to up sticks and move away for maybe two or three days, on the basis of a false prediction of Irma’s path. And for them that’ll be 10 million days lost, sitting wrapped in blankets on the floor of a community centre somewhere in the middle of nowhere.
Hurricane Irma was reported to be at latitude 23.9º, longitude -81.3º at 2.00 am EDT today, and at latitude 24.1º, longitude -81.5º at 5.00 am EDT, moving pretty much along the direction of my guessed path. The eye is going to pass over Key West, about 50 km from the southern tip of Florida. And hurricane force winds will barely brush it, now that Irma has been reduced to a Category 3 hurricane.
Clearly it’s going to be very wet and windy over most of Florida, but was it really necessary to order the evacuation of 6 million people?
P.S. Two hours after I posted this, Irma turned north and moved up the west coast of Florida almost exactly as forecast in the map above. Shows what little I know about weather forecasting.