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NOAA: Hurricane forecasts

Filed under: — group @ 9 June 2006

Guest commentary from Thomas Crowley

NOAA has issued its annual forecast for the hurricane season, along with its now-standard explanation that there is a natural cycle of multidecadal (40-60 year) length in the North Atlantic circulation (often referred to as the “Atlantic Multidecadal Oscillation”–see Figure), that is varying the frequency of Atlantic tropical cyclones, and that the present high level of activity is due to a concurrent positive peak in this oscillation.

AMO Pattern

There was not one mention of the possibility of global warming being a partial factor for these changes (see also this NY Times report on two recent studies).

trop. temperature - Anthes et al (2006) The average reader of newspaper articles on this prediction might well have concluded that there are in fact two camps on this subject – one global warming, one natural variability. But I think there is a one-way commingling of the camps. I suspect that most people leaning toward global warming as a contributor to the unusual increase in the magnitude of Atlantic tropical storms and hurricanes would readily concede the possibility that the AMO could, in addition to the El Nino/Southern Oscillation, modulate any greenhouse gas contribution to the enhanced activities of tropical storms.

It is not at all clear to me that the natural variability camp sees any need to commingle with the global warming community.

Is there any way to distinguish as to the relative strengths of arguments of these two camps? Actually, it is quite easy to do so. If the natural variability argument applies there should be little difference in the statistics of the present phase of the AMO with the past. But global temperature data incontrovertibly indicate that there has been a widespread warming since the previous positive phase of the AMO (e.g. 1940-1960). This type of warming cannot be produced by the ocean circulation, which to a first approximation just moves heat around on the planet – what it robs from Peter it gives to Paul.

Furthermore, rigorous statistical studies indicate that the pattern of warming can be attributed to greenhouse gas increase. I have seen no effort to conduct a standard “detection and attribution” approach to the alternate explanation of the AMO. I encourage the AMO proponents to try it; it is somewhat more objective than simple declarative statements that the AMO are responsible for the observed warming.

Update: The two papers referenced in the NY Times article are now available online: Mann and Emanuel (2006) and Sriver and Huber (2006).

168 Responses to “NOAA: Hurricane forecasts”

  1. 151
    S Molnar says:

    Re #147: I think social issues are fair game up to a point on RealClimate (but I’ll shut up about them if the proprietors disagree), and the problem of peak oil is relevant to the false dichotomy question. Some people who are waivering over their commitment to ameliorate global warming might become more reasonable when they realize that business as usual would not be an option for long even in the absence of warming. If big changes are coming anyway, why not start them soon and do them right? This argument might not persuade many, but small gains are better than nothing. I’m not sure I would cite James Kunstler on this, though, since his polemical style (which I personally enjoy) can be offputting.

  2. 152
    George A. Gonzalez says:

    Re: 147
    I see no evidence for the idea that the U.S. public is deeply committed to urban sprawl. As I outlined in #126, urban sprawl was ostensibly imposed on the public. European and Japanese cities are much more highly compact than U.S. urban zones, and they have no political problems resulting from this. In contrast, it could be argued that the U.S. government was compelled to engage itself in two Persian Gulf wars due to the U.S. economy’s high oil dependency. With 5 percent of the global population the U.S. consumes 25 percent of the world’s petroleum production. Over half of this is used for automobiles.

  3. 153
    Henk Lankamp says:

    The AGU published a report on “Hurricanes and the U.S. Gulf Coast: Science and Sustainable Rebuilding” (see here). A paragraph on hurricane prediction says:

    “There currently is insufficient skill in empirical predictions of the number and intensity of storms in the forthcoming hurricane season. Predictions by statistical methods that are widely distributed also show little skill, being more often wrong than right. Advanced global models are beginning to show some ability to predict seasonal characteristics. Examples include the coupled ocean-atmosphere climate models used in extended prediction by Meteo-France, the European Centre for Medium-Range Weather Forecasts (ECMWF), and the UK Meteorological Office. On 1 May 2005, the Meteo-France model predicted 22 named tropical storms and hurricanes for the 2005 hurricane season in the North Atlantic. On 1 June the ECMWF and the UK Met Office integrations were showing similar results. What was extraordinary about these forecasts was that their predictions, some months in advance of the hurricanes, were two standard deviations above the already elevated 1995â��2004 mean. These models also forecast a reduced number of storms for the northwestern Pacific during the same period. In hindcast mode these three models have outperformed statistical forecasts over the previous 10-year period of elevated storm activity. Yet despite these successes and the clear promise of the techniques, no operational model within NOAA is making extended range forecasts with climate models.”

    On 16 May 2005 the NOAA outlook was for 12-15 named storms, and on 31 May 2005 the Colorado State University (Gray & Klotzbach) outlook was for 15 named storms. The 2005 Atlantic season ended with 28 (sub)tropical storms.

  4. 154


    “On 16 May 2005 the NOAA outlook was for 12-15 named storms, and on 31 May 2005 the Colorado State University (Gray & Klotzbach) outlook was for 15 named storms. The 2005 Atlantic season ended with 28 (sub) tropical storms.”

    Not impressive predictions, yet Gray et al. are considered top-notch hurricane forecasters. There must be some other reasons why they are so much respected, although I have not heard it yet. Perhaps they have not considered other forecasts which predicted 2005 as warmest year in history, their failures was attached to their AMO isolationist belief that GT’s are irrelevant.

  5. 155
    cwmagee says:

    re 153:
    Do the Europeans have forcasts for this year?

  6. 156

    Media darlings are often scientific embarrassments.

  7. 157
    Gareth says:

    Re #153 And what, may I ask, are the relevant (European) prognostications for the current season?

  8. 158

    James Titus, EPA project manager for sea level rise, wrote an article in 2000 titled “Does the U.S. Government Realize That the Sea Is Rising?â�� When the journalist Cornelia Dean called him for a NY Times article (â��Next Victim of Warming: The Beachesâ�� June 20, 2006), Mr. Titus said he was no longer allowed to discuss such issues publicly. He referred questions to the agency’s press office, which would not allow him to speak about it on the record. How is it that we have come to this, that American citizens tolerate this blatant muzzling of public debate?

    A coastal engineer is quoted in the article as saying that â��he does not foresee the kind of sea level rise predicted by the (IPCC).â�� If he had to, he would bet that the 21st century sea level rise would be no greater that the 20th century rise. He predicts that â��engineers will be able to hold 99 percent of the Florida shoreline.” This while Floridians are not only preparing for the 2006 hurricane season, but still trying to recover from 2005 and 2004 hurricane damage. Denial not just a right-wing think tank product, it is deep in the heart of the economic and political system.

  9. 159
    Dan says:

    I think the point about hurricane season outlooks is whether or not they show skill over climatology. Which they do. Unfortunately too much emphasis is made on the specific number of named storms. What is more important is whether more storms are likely in a given year as compared to climatology.

  10. 160
    pat neuman says:

    Re: 144. 141.

    Questions about authority within NHC, NWS and NOAA

    The National Hurricane Center (NHC) is under the authority of (National Weather Service) NWS headquarters. NWS is under NOAA headquarters. The NOAA administrator is a political appointee. In past years, NWS did not answer directly to NOAA and DOC administrators, which seems to have changed in recent years. NWS and NHC now seem to answer directly to NOAA (and DOC?). NWS was created in 1870 (originally called the Signal Service, 100 years before the umbrella agency called NOAA was created). Today there are about 120 National Weather Service Offices and thousands of volunteer cooperative weather observers. I was proud to say that I was a NWS employee for most of my career, until the recent years and now. Now I’m not proud, to say I’m a NWS retiree (30 years).

  11. 161
    Tonya says:

    There are only two days left to comment on a review of NOAA’s hurricane forcasting …is anyone here participating??? I hope so.

    From Union of Concerned Scientists:
    “An external review of NOAAâ??s Hurricane Intensity Research and Development Enterprise has been released for public comment. The NOAA Science Advisory Board (SAB) announced the availability of the preliminary report of the SAB Hurricane Intensity Research Working Groupâ??s (HIRWG) external review for public comment. The report can be found at

    The Under Secretary of Commerce for Oceans and Atmosphere requested the SAB to conduct an external review of NOAA’s hurricane intensity research and development enterprise. Details on the reportâ??s draft recommendations are appended below. â??The report recommends that NOAA strengthen its efforts to develop numerical models which incorporate essential physics and have sufficient resolution to resolve hurricane structure. The essential physics includes full representation of clouds and a much improved representation of the exchanges of heat, moisture, and momentum at the atmosphere-ocean surface. Development of these representations will require extensive analysis of data from carefully planned field studies using both traditional airborne and ground-based observing systems and novel observing platforms such as Unmanned Aerial Vehicles.â??
    The report is open for comment until 5pm (EST) on June 23, 2006. Email comments are encouraged Directions for postal mail are below. When submitting comments, include: your name(s), organization(s), area(s) of expertise, mailing address(es), telephone and fax numbers, e-mail address(es).
    Deadline: 5 pm (EST) June 23, 2006

    About forcasting, I found this link to June 6th, 2006 hurricane season forcast from UCL, UK

  12. 162
    Coby says:

    I know it is late in coming, but as per request from Stephen Berg way up thread, I have a brief response to that Tom Harris article in CanadaFreePress here:

  13. 163

    Small follow up:

    Stephen Hawking elaborated on his Global Warming warning, this from AP on the web a few moments ago:;_ylt=AuBqGfx2Cn.VNIKwUceu5SGmG78C;_ylu=X3oDMTA2ZGZwam4yBHNlYwNmYw–

  14. 164
    pat neuman says:

    None of NOAA’s National Weather Service staff were at the “Looking for Leadership – A Global Warming Colloquium” in St. Paul last night, nor were any other federal or state “leaders” present at the meeting. Thus, unlike a public release today in Wisconsin on air quality, there was not a “cooperative effort involving the National Weather Service, public, community organizations, the media … and other state and federal agencies” – on climate change and global warming.

  15. 165

    You’ve got a typo in your Sriver and Huber URL: missing h in https.
    Should be:


  16. 166
    Robbie Collins says:

    I’m a lay person and just wanting to understand this criticism.

    #159:”Unfortunately too much emphasis is made on the specific number of named storms. What is more important is whether more storms are likely in a given year as compared to climatology.”

    In other words, whether a prediction that works with apparent forcing factors gives a usefully more accurate picture of seasonal.

    The specific number of named storms is a prediction that gives lay administrators a palpable measure: in other words, it isn’t expected to tightly couple issues of overall climate, but rather to provide direction to people who must react. The first thing the weatherman does (the weatherman is the lay-person’s number-one educator, and often slips in some key aspects of the actual science), talking about the coming/current season is talk about named storms. I knew from watching the local news that this year was predicted to have somewhere on the order of 14 named storms … only shortly (few months) after the last season. Overall, I expect a storm-season that is ~60% as bad as last year â�� that’s still hella bad, but in a way it is comforting. And overall, given the peaks in “named storms” over the unadjusted global tempertures, I know it can fall far below or aboe that in a given year so, things could be much better (or, alas, worse). Anyway, that’s my approximation of what a layperson gets from the reports.

    It has nothing to do, particularly, about the model or models in use, the nature of climate in general, or anything else. When looking at a Hurricane Seasonal Outlook report, what should I be seeing, and why is the particulars of any model relevant at this level?

  17. 167
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