2007 Tropical Cyclone Year in Review

Total of 55 Northern Hemisphere Tropical Cyclones: Maximum Intensity attained: 27 Tropical Storms, 11 Category 1, 4 Category 2, 1 Category 3, 7 Category 4, 5 Category 5. Total of 13 Major Cyclones.

As reported October 29, 2007, on Fox News Special Report with Brit Hume:

And now the most riveting two minutes of television, the latest from the Political Grapevine. While NOAA, the National Oceanic and Atmospheric Administration and other scientists predicted above average hurricane activity this year, the northern hemisphere is actually experiencing near historic inactivity so far in 2007. Florida State University Meteorology graduate student Ryan Maue says during the last 30 years, only in 1977, 1981, and 1983 have had less activity based on what's called the "Accumulated Cyclone Energy Index," which factors in storm intensity, frequency, and duration. It is the same index, by the way, used by NOAA. Maue points out the year is not over yet, and things could change. Some global warming alarmists, you remember, issued predictions of an era of stronger and more frequent hurricanes following the devastating storms of 2005. But Maue says the ocean's north of the equator are in fact calmer than they have been since 1977.

Plenty of other outlets covered this great news including Rush Limbuagh, Phil Valentine, NY Times, Bloomberg as well as numerous Florida newspapers. However, no mainstream media coverage occurred and none was expected. Hurricanes and climate change occurs at the intersection of politics and media and is an issue that does not lend itself to fair reporting.

The 2007 Atlantic Hurricane season did not meet the hyperactive expectations of the storm pontificators. This is good news, just like it was last year. With the breathless media coverage prior to the 2006 and 2007 seasons predicting a catastrophic swarm of hurricanes potentially enhanced by global warming a la Katrina, there was plenty of twisting in the wind to explain away the hyperbolic projections. The predominant refrain mentioned something about "being lucky" and having "escaped" the storms, and "just wait for next year". Of course, each year brings its own risk of another catastrophic hurricane, but global warming cannot be blamed.

The 2007 Atlantic Hurricane season was below-normal and tied for 2002 as the most inactive since the El Nino depressed 1997 season in terms of storm energy [*].

The North Atlantic was not the only ocean that experienced quiet tropical cyclone activity. The Northern Hemisphere as a whole was historically inactive.How inactive? One has to go back to 1977 to find lower levels of cyclone energy as measured by the ACE hurricane energy metric. Even more astounding, 2007 was the 4th slowest year in the past half-century (since 1958).

Fewest Northern Hemisphere Hurricane Days since 1977. 3rd Lowest since 1958 (behind 1977 and 1973) and half the value of 2004. Hurricane Days Graphic

When combined, the 2006 and 2007 Atlantic Hurricane Seasons are the least active since 1993 and 1994. When compared with the active period of 1995-2005 average, 2006 and 2007 hurricane energy was less than half of that previous 10 year average. The most recent active period of Atlantic hurricane activity began in 1995, but has been decidedly less active during the previous two seasons.

When combined, the Eastern Pacific and the North Atlantic, which typically play opposite tunes when it comes to yearly activity (b/c of El Nino), brushed climatology aside and together managed the lowest output since 1977. In fact, the average lifespan of the 2007 Atlantic storms was the shortest since 1977 at just over two days. This means that the storms were weak and short-lived, with a few obvious exceptions. The figures below demonstrate the historic proportions of 2007 Tropical cyclone inactivity:

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Since 1995, Atlantic hurricane activity has been in an active phase while the Eastern Pacific remained relatively quiet. The current season, 2007, clearly has been the slowest in this active period.

The Eastern Pacific and North Atlantic basins COMBINED have an accumulated ACE of about 120 for 2007. Usually through the phenonema known as El Nino Southern Oscillation (ENSO), the two basins typically see behavior opposite one another (activity vs. inactivity). However, the 2007 ACE is the lowest since 1977 and 1970. Unfortunately, reliable intensity estimates do not exist for the E Pac prior to 1970. Nevertheless, it is clear that 2007 is one of the lowest 5 years out of the past 50.