The Hurricane Season Just Getting Underway is Likely to be Unusually Active

Hurricane Ike, 2008. NOAA photo.

The hurricane season officially begins tomorrow, June 1, and extends through November 30. Wouldn't it be nice to know exactly what to expect? Maybe someday, but the foreseeable future has us depending on forecasters who speak in terms of probabilities. Fortunately, they're getting pretty good at what they do.

Cutting to the chase, the recently-released hurricane forecast for the Atlantic Basin calls for an "active to extremely active" hurricane season. NOAA's weather experts believe there is a 70 percent probability that this hurricane season will bring somewhere between 14 and 23 named tropical storms (top winds at least 39 miles per hour), including 8 to 14 that reach hurricane velocity (74+ mph). Even more ominously, the forecasters say we should not be surprised if three to seven of those hurricanes turn out to be major ones (Categories 3, 4, or 5; winds 111+ mph).

These numbers give cause for pause. A season with that many hurricanes would rank as one of the most active on record. (If you're interested in reviewing America's hurricane history, including frequency, typical paths, major storms, etc., visit this outstanding NOAA site.)

What the forecasters cannot tell us is where hurricanes will strike and with what consequences. Hurricane Katrina's recent trashing of New Orleans and a long list of other storm calamities serve as a constant reminder that even a single bad storm in the wrong place can take human lives and cause catastrophic property damage. It's also true that relatively minor hurricanes arriving at the right places and times can do some very good things, such as giving polluted or stagnant coastal waters a good stirring (Florida Bay, for example, could use one of those) and bringing welcome rains to top off reservoirs, recharge aquifers, and green-up our lawns and golf courses. There is more than a little capriciousness to this. Some people might say it's a crap shoot.

The uncertainty factor being what it is, communities throughout the Gulf and Atlantic coasts will just have to do what they've always done, which is to prepare for the worst and hope for the best.

That includes National Park System units, of course, and not just the seashores and other units hard by the shoreline and vulnerable to the full forces of the winds, surges, and shrapnel effects. Hurricanes often do some of their worst damage through flooding that occurs well inland.

One of the more interesting questions at hand is whether and to what degree hurricanes will influence the impacts of the Deepwater Horizon oil spill. Unfortunately, this is a maddeningly difficult one to handle. It isn't just that we can't yet know where and when the tropical cyclones will hit. We also don't yet have a lot of key information about the spill, including the total amount of oil released in this ongoing event, how much of that oil (and in what condition) will end up at or near the surface and subject to transport by winds, currents, and eddies, and where the nasty stuff will be in the weeks and months to come. Though the spill is currently confined to the Gulf of Mexico, plausible scenarios place some of that oil on Florida's Atlantic Coast, and eventually as far north as New England.

There is yet another factor to ponder. While logic suggests that tropical storms and hurricanes should tend to push oily residues and tar balls coastward, where it can foul beaches, estuarine marshes, and other vulnerable places, it's not quite as simple as that.

The aftermath of the huge Ixtoc I oil spill is particularly instructive, since this spill reigned for nearly 30 years as the worst in the Gulf until Deepwater Horizon came along. During an awful nine-month period in 1979, the runaway Ixtoc I exploratory well in Mexico's Bay of Campeche dumped around three million barrels of oil into Gulf waters. Although more than 162 miles of beaches were fouled (including Texas coast ones), the severity of the impacts was not worsened by hurricanes. In fact, scientists who studied the matter concluded that the net effect of the storms was to help disperse oil that might have otherwise come ashore.

We'll just have to wait and see what this hurricane season will bring. It promises to be one of the most interesting in a long time.

Postscript: The hurricane outlook is a good deal less disturbing outside the Atlantic Basin, There is a 70% chance that Hawaii, which gets four or five tropical cyclones in an average season (including depressions, storms, and hurricanes), will see fewer storms this year.