Saturday, May 30, 2009

A milder hurricane season could still juice energy. And: Knowing your ENSO from a Hole in the Sea

I disagree with the premise of the first piece, it appears the author is practicing "pop hurricanology" but thought I should post it to show the practical [profitable? -ed] advantage of understanding this stuff. Right now, the expectations are for not just fewer hurricanes but for those that do form to have a slight tendency toward a more northerly track i.e. east coast vs. gulf coast landfalls.

With the caveat, of course, that these are some of the most complex systems that humans try to predict and being chaotic, it is probably a Fool's [trader's? -ed] game anyway.

From MarketWatch:
Fewer hurricanes are likely to gather over the Atlantic during the tropical storm season that starts Monday, but it would only take one or two aimed at key facilities to fan already rising oil and gas prices, analysts say.

The National Oceanic and Atmospheric Administration is expecting 14 storms compared to 16 last year, and fewer major hurricanes.

Still, this hurricane season again threatens to halt energy production and swamp key agricultural regions, raising the cost of natural gas, gasoline and even some food, and possibly waylaying a U.S. economy recovery....

...The storms that originate in the Atlantic Ocean can extend to the Gulf of Mexico, where nearly half of U.S. oil refining capacity is located. The region also produces about 15% of the country's supply of natural gas and 7% of its oil. During three out of the past five hurricane seasons, which runs from June 1 through November, natural gas prices made significant gains.

How much damage the expected hurricanes will do is a wild card, however. Meteorologists can't locate the exact landing place of a hurricane from an early forecast.

If they do make landfall, these major storms will likely add to supply concerns, giving traders a new reason to bid up commodity prices. These have seen a sharp rebound in recent months, mostly due to a weaker U.S. dollar and hopes for an economic recovery. Crude oil has rallied more than 90% from its February low, while natural gas has risen about 20% since the end of April. An index gauging the prices of major commodities has gained 14% this month....MORE

From WunderBlog:

El Niño chances rising for hurricane season
Sea surface temperatures in the Equatorial Eastern Pacific have been rising steadily for several months, and there is now a very real possibility that an El Niño event could occur during the peak of the Atlantic hurricane season, August - October.

This is important, since the number and intensity of Atlantic tropical storms and hurricanes is usually reduced during an El Niño year, thanks to the increased wind shear such events bring to the tropical Atlantic. Last month, Columbia University's International Research Institute (IRI) was giving a 30% chance of an El Niño event for the coming hurricane season; this month, they have bumped their odds up to 45%. The Australian Bureau of Meteorology notes that "recent trends are consistent with the very early stages of a developing El Niño". NOAA's Climate Prediction Center forecasts the current neutral conditions in the Equatorial Eastern Pacific will continue into the summer, but shows that their CFS El Niño model is predicting a moderate El Niño event for the coming hurricane season....

Figure 1. Sea Surface Temperature (SST) departure from average for the equatorial Eastern Pacific (the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region"). The +0.5°C mark is the threshold for El Niño conditions, and we are very close to that mark now. Image credit: NOAA's Climate Prediction Center.

...Which model to believe?
As is the case with all seasonal forecasts, El Niño forecasts are not very good, and don't do much better than flipping a coin....

What will an El Niño event do to hurricane numbers?
Since the active hurricane period we are in began in 1995, there have been four El Niño events (Figure 3). During these years, the number of named storms, hurricanes, and intense hurricanes 11 named storms, 5 hurricanes, and 3 intense hurricanes. This is close to the average levels we've seen over the past 60 years--10-11 named storms, 6 hurricanes, and 2 intense hurricanes. If, on the other hand, we look at the five years that had neutral conditions, the numbers are considerably higher--18 named storms, 10 hurricanes, and 5 intense hurricanes. So, let's hope for an El Niño this year.

Note, though, that one of our worst hurricane years--2004, which featured hurricanes Ivan, Charlie, Frances and Jeanne, which all affected Florida with hurricane conditions--was an El Niño year. It seems that in years like 2004, there is a lag between the time a El Niño event develops and the response of the atmosphere over the Atlantic. There is no way of forecasting at this point whether this could be the case this year. One argument against a repeat of 2004 is the presence of much lower heat content and SSTs in the tropical Atlantic this year compared to 2004.

Figure 3. Looking at the numbers of Atlantic names storms, hurricanes, and intense hurricanes since 1995.

The hole in the ocean line refers to the relationship between Sea Surface Temperature anomalies and Sea Surface Height anomalies. Long way for a short yuck, I know.
[PDF]Impact of Sea Surface Height Anomalies on Cyclone Track M. M. Ali ...
See also:
More on the Possibility of a Hurricane Striking New York City
Hurricane Forecast Reduced ( "Remarkable Cooling in the Atlantic ...")
AccuWeather cuts 2009 Atlantic hurricane forecast. And: Bill Gray May do the Same
WSI Updated 2009 Hurricane Forecast;. And: El Nino odds rising with warming Pacific