Director’s Note: Entering the Wet Season Transition
You can feel it and hear it starting again, that familiar sticky humidity settling in, the rumble of thunder, the smell of rain hitting hot afternoon pavement. It feels like the wet season has arrived. But we’re not there yet. We are in the prelude to the wet season.
Even though we’re starting to see rain falling from the sky, this isn’t the signal that the drought is broken. We still have a long way to go. Our aquifer and surface waters are well behind, and it may take on the order of 20 to 30 inches of additional rainfall to catch up. Conditions across the region remain dry, wildfire danger is still elevated with wildfires regularly popping up from lightning strikes, and we are firmly in an extreme drought phase.
This is the in‑between time of year. Humidity is increasing, and rainfall is beginning to pick up, but the wet season hasn’t fully set in. The drought isn’t behind us, and the added rain hasn’t yet translated into recovery. With a rainfall deficit close to a foot and a half, it’s going to take sustained, consistent rainfall to move the system back toward balance, not just a few scattered storms.
Out in the bay, you can see the seasonal transition take shape. The low productivity gin‑clear waters of winter are giving way to the more productive tinted waters of late spring and summer. Natural, beneficial algal blooms, the kind that support the base of the food web, are beginning to take off. They draw nutrients from the bay waters and the little runoff currently making it into the system. Baitfish are starting to return in greater numbers to feed on these blooms, and with them come the larger predators. It’s the system responding to the spring bloom the way it typically does this time of year.
Scenes from Late Spring
What matters now is how the rain returns. In a trickle or a waterfall. After more than a year of drought, the landscape has built up a considerable load of nutrients. When rainfall returns, those nutrients will be mobilized and flushed into our waterways. If that happens gradually, the system has a chance to adjust. But if we shift quickly into heavy, sustained rainfall, those nutrients, along with pollutants and debris, can move rapidly off the landscape and into the bay. With fewer natural wetlands and a dominance of hard surfaces across our watershed, that runoff moves quickly and in concentrated pulses.
We can’t control the amount of rain, and we can’t control its timing. What we can influence is the amount of nutrients and pollutants leaving the land and entering our waters during the summer wet season. Higher nutrients during the wet season can set up conditions that enhance harmful algal blooms that develop in the heat of late summer and early fall. Red tide is one harmful algal bloom that can develop at any time, but late summer and early fall are when they tend to be a common occurrence when nutrients are elevated, and wind patterns bring red tide inshore. Conditions are tracked closely through tools like the FWC weekly red tide sampling, the NOAA National Centers for Coastal Ocean Science satellite imagery, and USF Ocean Circulation models that predict and track red tide blooms.
Hurricane season remains a major wildcard for the conditions in our region. Storms can act as system reset buttons, sometimes making conditions worse by flushing pulses of runoff into the system, and other times improving conditions by mixing and diluting coastal waters. But this is something we will talk about later in the summer as the summer weather pattern settles in.
This isn’t meant to be alarmist. It’s simply recognizing where the chess pieces are aligned on the board right now and how they can interact as they move through the wet season.
Layered on top of all of this is a developing strong El Niño pattern. Warmer-than-average Pacific Ocean temperatures are already influencing global conditions. Historically, strong El Niño events have reduced hurricane activity in the Atlantic due to increased wind shear, while also bringing wetter conditions to Florida during the winter months and increasing the likelihood of stronger (non-tropical) storm systems. At the same time, elevated water temperatures closer to shore can put stress on marine organisms, particularly in shallow systems.
All of this reinforces just how connected our local conditions are to larger climate patterns.
As we move forward, we’re shifting from a period of reduced nutrient loading during drought to one where those loads may increase significantly as rainfall returns. How quickly and how intensely that shift happens will shape the condition of our bays over the coming months.
For now, the focus is on watching the system respond, day by day, week by week, and understanding how these factors come together as we move deeper into the wet season.