The hurricane forecasting team at Colorado State University, led by Dr. William Gray, has published its preliminary hurricane outlook for 2014: below normal activity.
In addition, the National Hurricane Center has reduced its estimate for the top winds in infamous Hurricane Camille (1969), elevating Andrew (1992) to the top spot.
The Demotion Of Hurricane Camille
The National Hurricane Center has undertaken a review of past hurricanes, particularly significant ones; its task is complicated and the purpose unclear. However, there is a lesson to be learned from the reclassification of Camille.
Determining Top Winds In A Hurricane
The question is not as philosophical as whether a tree falling in the forest makes a noise.
The wind blows just as hard in a hurricane whether or not there’s an instrument there to measure it. Since most anemometers are incapacitated or just plain destroyed by category five hurricane winds (over 155 miles per hour), there is often little direct evidence of the actual speed of winds.
The highest wind recorded in Camille was 130 miles per hour at an offshore buoy. Originally the top winds on land were estimated at 190 miles per hour, predicated on the destruction the storm caused. Now the top winds have been reduced to 175 miles per hour, based on a wind of 115 miles per hour measured 70 miles inland. There is a known trend of wind degradation as a hurricane moves inland, and the final verdict is based on an extrapolation. Take it, still, as an estimate.
A couple of dozen people at the Richelieu apartment building in Pass Christian, Mississippi chose to ignore evacuation warnings and party out the storm. I suppose it was fun for a while, but when the building collapsed and washed away, fun turned to horror. Twenty-three of the revelers died; the 24th was found five miles inland clinging to a tree.
It would have made little difference to know the top winds were 175, not 190, miles per hour; it would be like the difference between being run over by a train with a caboose and a train without one.
Hurricanes And El Niño
The Colorado State forecast of only nine named storms this year (average is 12) is primarily based on the likelihood that an El Niño will develop this summer. But the correlation between hurricane numbers and El Niño is tenuous, and the correlation with major hurricanes may be inverse.
Hurricanes Andrew and Camille, the most powerful since 1950, both occurred during modest El Niño years.The relationship only shows up clearly during strong El Niños. The last powerful El Niño was in 1998, a year which produced only seven named storms.
The Accuracy Of Last Year’s Forecasts
2013 was a quiet hurricane season, well below average. Let’s see how the major prognosticators did.
On May 23rd, The National Hurricane Center issued a forecast for a very intense season. Way wrong. On August 2, The Colorado State team issued an update for the season’s forecast — and still insisted, now one-third of the way through, that the season would be very active. All forecasts for future hurricane seasons should refer to this result as an example of what can go wrong.
So take the Colorado State forecast as basically a reminder that there IS a hurricane season and that it is coming soon.
The Decoded Science Hurricane Forecast For 2014
It is the view of Decoded Science that both the National Hurricane Center and Dr. Gray do a disservice to residents of hurricane-prone areas by issuing these early forecasts and proclaiming them anything more than barely-educated guesses.
Colorado State has thrown in the towel on its December forecast, admitting it had no value.
April’s forecast is, judging by the historical record, only very marginally better, and it gives people false impressions. Most importantly, there is no correlation between the most destructive hurricanes and the total tropical activity for the seasons in which they occurred.
In 1992, there had not been a named storm until Andrew in late August, practically halfway through the season, and 1992 ended up with only six named storms.
So here’s our admittedly barely-educated guess:
Conflicting signals indicate that all forecasts should be issued with even more than the usual emphasis on the fact that hurricane forecasting long in advance is of very suspicious value.
That said, we don’t see the El Nino as being a dominant factor this year, so we believe the season is likely to be above normal in activity.
Water temperatures in much of the Atlantic basin are above normal, and we have been in a period of increased activity since 1995. The fact that no major hurricane (category three or higher) has made landfall in the U.S. since 2005 (Wilma) should have no bearing on the forecast, though some might say we’re overdue.
The Bottom Line
If you are in a zone that can be affected by a hurricane, do not put any credence in long-term hurricane forecasts. Prepare every year as though a big one could strike — because it could. If a hurricane threatens, DO pay attention to short-term forecasts, watches and warnings. Remember the Richelieu.