Hurricane Season began June 1 and runs through November 30.
The hype around the date is unjustified, as there is only one named storm in June every five years, and only one major hurricane has hit the US coast in June since 1850.
We aren’t likely to see the first named storm of the season, Arthur, until at least July.
Hurricane Forecast Comparison
In addition to the well-publicized forecasts from the National Hurricane Center (NHC) and the Colorado State University Tropical Meteorology Project (CSU), there are prognostications from several other sources.
In order to make valid comparisons, we will only consider forecasts that have been issued for the last five years. The other two forecasts that qualify were issued by Florida State University’s Center for Ocean-Atmospheric Prediction Studies (FSU), and Tropical Storm Risk (TSR), a public consortium consisting of experts on insurance, risk management, and seasonal climate forecasting at University College, London.
Who Made The Best Forecast?
The forecasts are made for number of named storms, hurricanes, and major hurricanes, as well as a quantity called Accumulated Cyclone Energy (ACE), a measure of the total intensity of a hurricane season.
The results of comparing the NHC, CSU, FSU, and TSR forecasts for the past five years are a little surprising:
- Colorado State University, which promotes its forecasts aggressively, came in dead last in every category. In fact, a forecast of the long-term averages for tropical storms, hurricanes, and ACE would have been just as good as the CSU forecast.
- The FSU forecast beat all the others in every category.
- Little-known TSR tied NHC in the middle of the pack.
None of these forecasts help residents of hurricane-prone areas to know how to act. They contain no information about where storms are likely to make landfall. They also say nothing specific about the distribution of storms among the strength categories, or whether storms will be long-lived or flashes-in-the-pan.
What Are The Odds Of A Major Hurricane Striking Where You Are?
In the 20th century, 158 hurricanes made US landfall; 64 of them were major hurricanes. The places most at risk are the northern and western Gulf of Mexico, south Florida, North Carolina, and Long Island. At any particular spot in one of these locations, a major hurricane strikes about once every 30-35 years, so in any given year the chance of a hit is 3%.
Now consider a year in which the forecast calls for a very active season — say twice the normal number of major storms (none of the major forecasters has ever made such an extreme forecast). That means a major hurricane would strike every 16 years, and the chance of getting one this year is 6%. Is that of any help in planning?
The Value Of Long-Range Hurricane Forecasts
Decoded Science takes the position that long-range hurricane forecasting should be viewed as only an academic exercise. Given the media attention that comes with their releases, these forecasts now serve only to promote either anxiety or complacency, neither of which is justified.
Until such time as forecasts yield useful information, they should be labeled ‘experimental’ and published with the disclaimer that they may have no predictive value and are often just plain wrong. Even when the numbers are reliable, there is no way to predict the exact locations of hurricane landfalls or the intensities of the storms more than a few days in advance.
Hurricanes: Last Year’s And This Year’s Forecasts
Last year’s forecasts were wrong. This year’s forecasts, based mainly on the expected development of an El Niño, are for an inactive tropical Atlantic season.
In view of last year’s disastrously bad forecasts for an active season based on La Niña, Decoded Science is skeptical. We have predicted that the coming hurricane season will see above-average activity.
This forecast is based on the simplest of reasoning: the sea surface temperatures (SST) are above average. We feel that SST trumps El Niño, both theoretically and empirically, as a predictor of hurricane numbers and intensity.
In any event, let us not forget that Hurricane Andrew, one of only three landfalling category five hurricanes ever recorded in the US, occurred in 1992, a year with only about half the long-term average number of storms. And, yes, 1992 was an El Niño year.
Planning For A Hurricane
There is much more useful information available than the official and unofficial hurricane forecasts. Here are a few things to keep in mind as you prepare:
- Half of hurricane-caused fatalities are from storm surge. If there’s a hurricane near, GET AWAY FROM THE OCEAN. Have a suitable evacuation plan.
- A quarter of fatalities are caused by rain and inland flooding. STAY AWAY FROM STANDING OR FLOWING WATER.
- Only 8% of fatalities are caused by wind. This doesn’t mean you should ignore the wind, which is responsible for much of the physical damage done by hurricanes; batten down the hatches for sure. But a house can be replaced.
Some statistics don’t lie: the killer in a hurricane is the water.