Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 3:27 PM GMT on December 10, 2009
A return to the pattern of above-average Atlantic hurricane activity we've seen since 1995 is on tap for 2010, according to the latest seasonal forecast issued today by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). In a departure from their usual forecasts, the Klotzbach/Gray team is issuing a range of numbers for storms, instead of forecasting a specific number. They are calling for 11 - 16 named storms, 6 - 8 hurricanes, and 3 - 5 intense hurricanes. An average season has 10 - 11 named storms, 6 hurricanes, and 2 intense hurricanes. The new forecast calls for a near-average chance of a major hurricane hitting the U.S., both along the East Coast (40% chance, 31% chance is average) and the Gulf Coast (40% chance, 30% chance is average). The Caribbean is also forecast to have an average risk of a major hurricane.
The forecasters cited several reasons for an above-average season:
1) "Warm sea surface temperatures are likely to continue being present in the tropical and North Atlantic during 2010, due to the fact that we are in a positive phase of the Atlantic Multidecadal Oscillation (AMO) (e.g., a strong phase of the Atlantic thermohaline circulation)".
2) Hurricane activity in the Atlantic is lowest during El Niño years and highest during La Niña or neutral years. The CSU team notes that while we are currently experiencing moderate to strong El Niño conditions, it is very rare for an El Niño to last through two consecutive hurricane seasons: "Seven out of the last thirty-five years in an active era (20%) were classified as warm ENSO events. None of the past seven events had El Niño conditions persist through the second year, and every event except for 1951-1952 had an increase in tropical cyclone activity during the second year. It should be noted that an active era and the absence of El Niño does not guarantee an active season, as both 1952 and 2007 experienced near-average net tropical cyclone activity."
How accurate are the December forecasts?
The CSU real-time December forecasts have not shown any skill over the period 1992 - 2007, so we should view the latest forecast as an experimental research product. In 2008, CSU junked the old December scheme and came up with a new one. This year's December forecast uses the same formula as last year's December forecast, which over-forecasted the 2009 hurricane season. That forecast called for 14 named storms, 7 hurricanes, and 3 intense hurricanes, and we actually had 9 named storms, 3 hurricanes, and 2 intense hurricanes. However, the new scheme will need to run for 5+ years before we can get an idea of whether or not it has any skill.
Figure 1. Forecasts of El Niño conditions by 20 computer models, made in November. The longest range forecasts for July-August-September (JAS) at the right side of the image show that most of these models are predicting an end to El Niño by then. El Niño conditions are defined as occurring when the average sea surface temperature in the Equatorial Pacific off the coast of South America rises above 0.5°C (top red line). Image credit: Columbia University.
2010 Atlantic hurricane season forecast from Tropical Storm Risk, Inc.
The British private forecasting firm Tropical Storm Risk, Inc. (TSR), issued their 2010 Atlantic hurricane season forecast on Monday. They are also calling for an active year: 13.9 named storms, 7.4 hurricanes, and 3.4 intense hurricanes. TSR predicts a 62% chance of an above-average hurricane season, 24% chance of a near-normal season, and only a 14% chance of a below normal season.
I like how TSR puts their skill level right next to the forecast numbers: 5% skill above chance at forecasting the number of named storms, 8% skill for hurricanes, and 14% skill for intense hurricanes. That's not much skill, and really, we have to wait until the June 1 forecasts by CSU, NOAA, and TSR to get a forecast with reasonable skill.
Bill Gray on global warming
I received this comment yesterday in my blog:
There is a problem with reality. It is reminiscent of a sci-fi story where half the people see one thing, and the other half see just the opposite. But there is only one truth, and an incorrect decision could lead to disastrous consequences. Who should we believe? The captain, who we've long admired and have great respect; or the first officer to whom we owe our lives? They are both good people, but only one of them is correct. The other has been misled. Post #639 presented by TomJonesAL of Dr. Bill Gray's scathing condemnation of the majority of the worlds scientific community's assessment of the current and projected trends of Global Warming can only give further pause to the average citizen who relies on common sense and the integrity of their leaders for an informed and accurate opinion. Dr. Gray is highly respected, but so too are the many members of the opposite train of thought, including Dr. Masters. So whom do we believe?
Climate science is an incredibly complex subject, and the science is too complicated for all but an expert to fully grasp. Complicating the issue is the fact that there is a large amount of natural variation, and we are now just beginning to to see a human-caused effect (or so many scientists are telling us). Clearly, we have to rely on scientists to figure out the problem and advise us on what is happening. But which scientist to trust? Obviously, one should not trust scientists receiving money from the fossil fuel industry--or the wind power industry, for that matter--since these scientists might have a vested interest in a particular view. You are also hearing statements from sources like the Wall Street Journal and Dr. Bill Gray that we can't trust climate scientists because they are "vested interest scientists wanting larger federal grants and publicity", as Dr. Gray puts it. So, if you reject those scientists as sources of information, you are left with non-climate scientists that you trust. I will try to give you some relevant background on Bill Gray and myself, so that you can come up with your own answer for which of us is more likely to have the correct answer.
Figure 2. Dr. Bill Gray at the podium of the 2006 American Meteorological Society hurricane conference in Monterey, California.
Bill Gray has been an outspoken critic of the the science showing human-caused global warming, and of many of the scientists involved. His December 8, 2009 post on climatedepot.org is a typical example of his views. Dr. Gray is one of the greatest experts on hurricanes, and has published hundreds of peer-reviewed scientific papers on the subject. He has not published any papers on climate change. His expertise is primarily data-based observational science and forecasts using statistical models; he does no theory and highly distrusts all climate science done using General Circulation Models (GCMs). He has been a rabble-rouser at professional conferences I have attended, insulting colleagues and interrupting their talks. At one conference I was at, he chided a fellow researcher about his use of computer models to do climate research, saying, "I didn't know you as a religious person. That's a belief". Gray himself has not done research using the type of computer forecast models he is critical of. His primary career goals: "I am now giving more of my efforts to the global warming issue and in synthesizing my projects' many years of hurricane and typhoon studies". He has no ties to the fossil fuel industry, and told the audience at one talk I was at that he votes Democratic. You can find many profiles on Dr. Gray through a simple Google search on the term, "Bill Gray global warming", or by visiting his Wikipedia page.
Like Bill Gray, I have not published any papers on climate science. As I have spent most of my career developing Wunderground.com, I have published just five peer-reviewed scientific papers, and none since I got my Ph.D. My research has been on air pollution, and on airborne wind and pressure measurement in hurricanes. I did seven years of computer modeling during my air pollution science career. I used and modified the code of models that did 7-day weather forecasts, and of air pollution models that incorporated the full chemistry, solar radiation, and meteorology of the atmosphere. I do not have any experience using the General Circulation Models (GCMs) that were used to formulate the IPCC climate reports, though many of the components of the models I worked with are incorporated into GCMs. My modeling experience has led me to believe that the models used to formulate the IPCC report are valid scientific tools that are sufficiently accurate to give us a general idea of where our climate is headed. I belong to one environmental group, the Nature Conservancy. Politically, I do not label myself a Democrat or Republican, because I believe that both parties are fundamentally corrupted by the money large corporations give to them. I see an urgent need for campaign finance reform and limits on lobbying in order to restore the democracy our Founding Fathers envisioned. My primary career goal is to gain as deep an understanding of the atmosphere as possible and communicate that knowledge to those interested. I am looking forward to serving in that role for many more years--the next decade will be an extremely interesting one, and we should have a pretty definitive answer as to who is right by the end of the decade.
I'll have a new post Friday, there's a lot going on.
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