Hurricane Forecasts, Fulminations, and Flossie

We have an almost-hurricane named after one of the Bobbsey Twins spinning in the direction of Hawaii right now ... but I'll get to that.

First, another look at the great race to be very right (or very wrong) about how many storms we'll get in the Atlantic basin this hurricane season. In the past week or so, the top hurricane forecasting teams have all released their updated August predictions. There hasn't been a hurricane yet, and there have only been 2 or 3 tropical storms (depending upon how you count) -- but the teams remain bullish.

Phil Klotzbach and William Gray of Colorado State University say 15 total storms (2 of which we've already seen, they say). And they add a prediction that 8 of those will become full-fledged hurricanes and 4 will reach Category 3 or higher. Over at Tropical Storm Risk in the UK, meanwhile, they're making a similar prediction of roughly 14.7 total storms (+/- 2.9), 7.8 hurricanes (+/- 1.7), and 3.5 intense hurricanes (+/- 1.3). Finally, the U.S. National Oceanic and Atmospheric Administration (NOAA) predicts 13-16 named storms, 7-9 hurricanes, and 3-5 intense ones.

In short, though these groups express their prognostications in a somewhat different format, they're all pretty much on the same page. But how can the forecasters continue to predict all this action when so far we've seen almost nada? This figure provided by NOAA helps explain:

As you can see, the large bulk of Atlantic hurricanes have historically occurred between mid-August and mid- to late-October. So you can imagine what the forecasters are thinking. They know that we're only now moving into the busy part of the typical season, and they see an atmosphere-ocean system that's quite ripe for hurricanes, featuring warmer than average sea surface temperatures and the likelihood of at least weak La Nina conditions in the Pacific (which tend to be conducive to Atlantic hurricanes). So of course they're still forecasting an active year.

However, it's still worth listening to a counterpoint from hurricane expert Jeff Masters, who opines that the forecast teams "are all calling for an awful lot of tropical storm activity in a relatively short period of time. I think it is likely that the total number of named storms this year will be at the lower end of NOAA's range -- 13." I'm not a betting man, but I tend to trust Masters (who almost died flying into Category 5 Hurricane Hugo in 1989; read here for the incredible story.)

But in any event, can someone show the above picture to Freakonomics co-author Steven D. Levitt? In a recent blog post the economist opined, "Two months into what was supposed to be a very active season, with 7-10 hurricanes predicted, so far not a single hurricane has appeared. By this time in 2005, there had already been three hurricanes." Well, if every year was 2005 there might be nobody left living on the coasts. One would expect an economist not to confuse an outlier with the average. (For a more thorough critique of Levitt on hurricanes, see my blog here.) Meanwhile, as we wait for all these incessantly predicted hurricanes to show up and possibly affect the U.S. East and Gulf coasts, out in the Pacific Hawaii may actually be troubled sooner than any of us. A little storm named Flossie (hence the Bobbsey Twins reference above) is heading their way. Shown here in infrared, Flossie remains a strong tropical storm, and may or may not briefly become a weak hurricane as it travels farther westward. If the storm does affect Hawaii in some way, it won't be until early next week.

For further information on Flossie, visit the National Hurricane Center for regular updates. Or if those come out too slowly for you, you can be a geek like me and check out the automated "Advanced Dvorak Technique" estimates of the storm's intensity, inferred from satellite images of the storm and updated every half hour, courtesy of the University of Wisconsin-Madison's Cooperative Institute for Meteorological Satellite Studies. If Flossie reaches wind speeds of 65 knots, she's a hurricane, at least by this methodology.

In the meantime, I'll be back next week, and if we still have a quiet Atlantic, it may be time to really start questioning those forecasts....