Jan 17, 2012

Dry seasons of recent memory

Here’s a look at this year’s dry season (so far) …

Compared to the previous three.
Timing of rain is as important as amount

This year’s dry season has been very dry so far, but the unusually wet October filled the swamp up with water just in time for the low ET season of fall.

That was good news for the swamp because it gave that water staying power. The same rains in June are more easily evaporated and transpired away.


Compare that to the previous dry season, winter of 2010-11. October of that year was dry, plus the dry winter and, perhaps worse of all, a delayed and piddling start to the wet season.

That was bad news for the swamp because it exposed it to uncontrollable wildfires.


Now look at winter of 2009-10.

That was an El Niño year. Fronts were frequent and were stacked with lots of moisture.

Fronts like this were frequent and wet
during the winter of 2009-10.

Last on the graph is winter of 2008-09.

That was the driest dry season of them all, and as a result wildfires did sprout up in April, but May brought epic rains which put them all out.


What do all four have in common?

Each in its own way has been extreme, either on the wet or dry side. For each year, however, timing of rain, or lack thereof, has been just as influential as amount.

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