Dec 2, 2014

When a little goes a long way

The dry season is entering its cold phase.

That means evapotranspiration (ET) will be seasonally shutting down for the next three months.

The graph above reports the 7-day running rain total for Big Cypress National Preserve.  The dark black line shows the 7-day long-term median rain total.  The red dot shows where we are now.  As you can see, we are in the early stages of our long winter dry period and also the start of the cold period where ET drops down, or close to, zero.

From a water cycle perspective, even without any rain the water table only drops very slowly as a result. It isn't until March, April and May that ET starts to crank back up.  When that happens we will desperately depend on frontal rain showers to keep the water table from precipitously dropping down into deep drought.

As for now, a little rain goes a long way in cool winter months.

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