Q: What causes a sea breeze?
A: Sea breezes occur most commonly during the summer afternoons, when the air over land is hottest, says Brent McRoberts of Texas A&M University. “Because land heats quicker than the ocean, air over the continent becomes unstable and rises to create a relative low pressure at the surface,” he explains. “The air at the surface over the ocean is then drawn in toward the low-pressure center over land, creating an onshore wind. This sea breeze brings in much welcomed cooler air to the cities near the coast during the hottest times of the day.”
Q: Can sea breezes cause rain and thunderstorms?
A: In many cases, yes, but the effect varies with location, McRoberts adds. “The incoming sea breeze is cooler than the air over land. This creates a small-scale cold front called a sea-breeze front. Like most cold fronts, sea breeze fronts can create showers and thunderstorms that pop up along the frontal boundary because it lifts the warm air ahead of it, which leads to convection. Sea breeze storms are common during the summer in places like Houston or New Orleans. On the West Coast, however, the air is generally too cool to support convection even with the sea breeze front, so a type of fog and drizzle known as the marine layer occurs more often in this region. “