Friday, January 6, 2012

Current US Drought Map


To strengthen my (and hopefully your) intuition for the Palmer Drought Severity Index I'm going to try and post the current US map on a monthly basis.  For more background on the Palmer Index see this post.

The map for the week through Dec 31 is shown above.  You can see that most of Texas is still in the grips of an extreme drought and a lot of the southeast is also pretty badly off.  This continues a pattern that lasted through most of last year in which a lot of the southern half of the country was very dry while the northern half was unusually soggy.  However, the southern droughts are not as extensive now as they were at their height in August.

You can see a nice animation of the monthly PDSI for the whole of 2011 at NOAA's site.

You can also construct longer movies of any portion of the twentieth century you'd like to watch - for example here's one of the dust bowl years.  We still haven't managed to create anything that bad (in general most of the US has been trending wetter not drier under global warming) .

5 comments:

  1. Weird. The 12th slide of 12 (Dec 2011) shows a very different picture for Texas than the monthly one in your post...

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  2. I think the Southeast could really be the section that has trouble with this in the immediate future.

    Particularly Atlanta.

    They weren't too many days away from having to drink the dregs of Lake Lanier a few years ago. And I don't keep my ear tuned to Atlanta news but the general area hasn't had a lot of rain since.

    This region still has a lot of rainfall compared to areas like Arizona, but they've never had to build the infrastructure to deal with droughts. And now they have some very large cities here. Currently there is no political will to do so from what I gather either.

    They haven't done anything to address this. One more bad summer and I think you hear an awful lot about it.

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  3. John:

    At the time I posted the Dec monthly was not available and I used the weekly one for the last week of Dec. Sometime during the day the Dec monthly one became available. I agree with you that the differences in Texas are more than I would have thought - matter for further exploration I guess.

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  4. There's another drought monitoring effort that is appears more comprehensive than Palmer, although it lacks that interesting historical perspective. See http://droughtmonitor.unl.edu/

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  5. In related news:

    http://www.star-telegram.com/2011/12/20/3609114/up-to-10-percent-of-trees-in-texas.html

    --
    TL;DR.

    Trees are being killed by drought.

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