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No Increase In Extreme Weather In The Philippines

April 30, 2014

By Paul Homewood



We keep hearing claims that extreme rainfall events are on the increase, because of climate change. PAGASA, the Philippine Atmospheric, Geophysical and Astronomical Services Administration have done their own research, which suggests that, there at least, this is not the case.


In their study, “Current Climate and Observed Trends”, they conclude that:


 However, the trends of increases or decreases in extreme daily rainfall are not statistically significant; although, there have been changes in extreme rain events in certain areas in the Philippines.



They also show this chart of tropical cyclones from 1948 to 2010, that have passed through the Philippines Area of Responsibility. The trend is very slightly downwards.




They find:


Analysis of trends of tropical cyclone occurrence or passage within the so-called Philippine Area of Responsibility (PAR) show that an average of 20 tropical cyclones form and/or cross the PAR per year. The trend shows a high variability over the decades but there is no indication of increase in the frequency.


As for stronger storms, they find a slightly higher number during El Nino years, but, again, no overall trends:


 However, there is a very slight increase in the number of tropical cyclones with maximum sustained winds of greater than 150kph and above (typhoon category) being exhibited during El Nino events.






It may just be one country, but it seems we should take blanket claims of “increasing extreme weather” with a pinch of salt.

  1. John F. Hultquist permalink
    April 30, 2014 5:30 pm

    Thanks Paul.
    I realize the charts are not your doing so this is just me musing on presentation issues.
    The first chart with just green bars has a red line of “five year running means.” Because the minimum is 12 (?) and there is never an actual break (zero), the chart and the running mean presents a clear-enough picture.
    The second chart (all the colors –wow!) uses a black line for the same running mean, I think. It doesn’t say so.
    Running means help to visualize data when it is continuous (say the elevation profile of a river) or discrete but continuous-like, say the value of a company’s stock. Obviously-discrete data such as extreme typhoons shows the limits of this graphic device. The right-hand side of the chart looks odd. Means are sensitive to extreme values and having the very low period of 1998 – 2001 followed by the high period of 2003 – 2006 produces a black line that is out of sync with the image the bar height is showing. The false curve is off-set to the right so far that it isn’t adding to the explanatory usefulness of the graphic. Pick a spot on the line, say for 2010 where the line says about 5.5 and the actual number is 1. That seems of little use.
    At some point the people that prepare these charts ought to back away from their computer screens and their fancy software and let the data tell its story – if there is one. (Does the background of top and bottom green fading to white in the middle help?)

  2. tom0mason permalink
    April 30, 2014 6:37 pm

    thanks for the heads-up Paul

  3. May 1, 2014 10:28 am

    Reblogged this on CraigM350.

  4. Andy DC permalink
    May 1, 2014 4:55 pm

    Another set of charts showing that “global warming” or “climate change” is much to do about nothing.

  5. Mikky permalink
    May 1, 2014 5:59 pm

    Paul, sorry off-topic in this article, just wanted to ask about the strange green line in the Mets CET plot. Do you know what it is? It tends to “hide the decline”, but maybe there is an innocent explanation.

    • Mikky permalink
      May 1, 2014 6:37 pm

      Sorry, its probably just the current average for 2014, but it does do a certain job quite nicely, wonder if it would have been shown if we’d had a cold winter.

    • May 3, 2014 4:56 pm

      That’s the provisional figure for so far this year.

  6. May 3, 2014 12:27 pm

    Reblogged this on Reigate Grammar School Weather Station.

  7. May 3, 2014 12:28 pm

    Interesting post, thanks… hope you are happy for me to have reblogged this to http://www.rgsweather,com an educational weather site.

  8. May 4, 2014 6:34 am

    Glad you’ve come across this PAGASA report; it remains unmentioned in the Philippine press.

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