Sea Breeze / Land Breeze - The Gulf of Mexico Breathing

Florida doesn't have any mountains to look at but we do have some primo clouds. Clouds have interested me ever since I was a kid, but since getting into windsurfing and studying marine science, both of which require learning about the roles of ocean and atmospheric circulation in weather and climate, I've developed a cloud obsession bordering on the unhealthy. Clouds are neat in themselves, but their patterns and changes over time tell an awe-inspiring story of the planet's life; its giant, slow breathing and pulsing movements of water, energy, and heat. One cloud pattern I love to watch in summer in Florida is related to the seabreeze / land breeze cycle that unfolds each day and night.

Sea Breeze is wind that blows from the ocean towards the land. It's driven by solar heating of the land during the day, which causes hot air to rise over the land, drawing cooler air in from the sea. If conditions are right the seabreeze forms tall, billowing clouds as it rises over the land. These are the source of Florida's summer thunderstorms, which are particularly intense over the middle of the state where the Atlantic Coast sea breeze coming from the east collides with the Gulf Coast sea breeze coming from the west.

Land Breeze is the opposite of sea breeze. It's wind that blows from lands towards the ocean, when the ocean is warmer than the land so air is rising over the ocean and sinking over the land. It happens at night, because land cools off faster than water does. So when the sun sets in Florida the thunderstorms over land usually peter out, but majestic thunder clouds may form over the ocean. On summer mornings in Florida, especially on the Gulf of Mexico side, you can often look out and see gorgeous, side-lit walls of thunderclouds that formed over the ocean at night.

I can't see the beach from my apartment complex, but I know which direction to look to see those over-the-Gulf clouds, and they're often spectacular in the morning. Likewise, in the afternoon I look east to see the eruptions of storms forming inland, and I try to time my bike ride home from work to not get caught in them. Below is a comparison of the morning and afternoon skies today, demonstrating the pattern pretty well. (I should note that it's never exactly the same, and there definitely exceptions to the land clouds in the day, sea clouds at night rule, but the exceptions are interesting, too.)

Here's what the morning conditions look like on the iwindsurf.com radar. Land breeze pattern, with the activity over the ocean and nothing happening over land.

Here's what the afternoon conditions look like on the iwindsurf.com radar. Sea breeze pattern, with land heating generating rising air and thunderstorms over the peninsula, but not much going on over the waters.

This is the modeled wind strength and direction for the morning from iwindsurf.com. Air is still flowing off the land out into the ocean.

This is the modeled wind strength and direction for the afternoon from iwindsurf.com. You can see landward flow caused the seabreeze, plus locally increased winds around the thunderstorms.