Apr 3, 2013

Good dry seasons gone bad

Under tenth percentile is never good:

That's where Big Cypress Nat'l Preserve ranks this year, looking back from 1970 to present, in terms of total dry season rainfall accumulation.

This bar chart shows annual dry season rainfall accumulations from 1970 to present for Big Cypress Nat'l Preserve.  Bars that rise into the blue zone are what we call "wet" dry seasons and bars that stay in the red zone are what we call "dry" dry seasons.  Dry seasons have trended into the red zone over the past few years.  Not surprisingly, an increased occurrence of wildfires has followed.

In fact,

Five of the last ten dry seasons have scored under 25 percent. Over the same period, only dry season (Nov 2009 - Apr 2010) has been truly wet. Compare that to the wetter 1990s period where we had four "wet" dry seasons, i.e. above the 75th percentile, and only one marginally "dry" dry season (Nov 1995 - Apr 1996).


Sometimes the decades creep up on you like that.

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