How Does a Sea Breeze Form?

iStock
iStock

Walking outside during the summer can feel like walking into the bathroom after someone takes a shower. The muggy air gives you a great big unwanted hug, fogging up your glasses and forcing you into a gross and near-immediate sweat. If you're seeking relief, head to the beach: One of the great benefits of being near the coast is the cool afternoon breeze that takes the edge off of a hot summer day.

The sea breeze is a wind circulation that forms near the coast when there's a large difference between the temperature of the air over land and the temperature of the air over water. Land heats up much faster than water, so there's usually a big temperature gradient between, say, Mobile, Alabama, and the Gulf of Mexico just a few miles offshore.

The sea breeze process starts when warm, unstable air over the land begins to rise. This rising air creates a small area of lower air pressure at the surface. As part of Mother Nature's balancing act, cooler air over the ocean starts to rush toward land to fill the void left by the rising air. This eventually creates a circulation that continues for as long as daytime heating is present. As cooler air lingering over the water starts to spill inland, humidity goes up a bit, but air temperatures drop as much as 10°F to 15°F once it passes through. You don't need to be on the beach to reap the benefits of this phenomenon, either: A sea breeze can travel as much as 50 miles inland in some locations.

Aside from their cooling relief, sea breezes are most notable for the thunderstorms they can trigger near the coast. Sea breeze thunderstorms don't last for very long, but they can be a doozy, sometimes producing flooding rains, vivid lightning, and occasionally some damaging wind gusts.

Central Florida is famous for dealing with sea breeze thunderstorms almost every day during the warm season. The state's narrow shape allows two sea breezes—one from the Gulf of Mexico and one from the Atlantic Ocean—to collide with each other right in the middle of the peninsula. One sea breeze usually packs enough punch to fire up a hefty storm, but the lift created by two sea breezes colliding can trigger especially vivacious storms, as anyone who's ever visited Orlando's theme parks can tell you.

Once the Sun goes down and the sea breeze wanes, the opposite effect begins to take hold. Water holds onto its heat much better than the land, and as a result the air over the water usually stays warmer at night than the air over land. This disparity between land and sea causes what's known as a land breeze; it's the exact process that goes into a sea breeze, but blowing from the land out toward the sea instead. This process can also lead to thunderstorms, just close enough to the coast that anyone standing on the beach in the early hours of the morning can watch lightning flashing off in the distance.

What Is a Bomb Cyclone?

Maddie Meyer/Getty Images
Maddie Meyer/Getty Images

The phrase bomb cyclone has re-entered the news this week as parts of the central U.S. face severe weather. Mountain and Midwestern states, including Colorado, Nebraska, Wyoming, and South Dakota, all fall in the path of a winter storm expected to deliver tornadoes, hail, heavy snow, flooding, and hurricane-force winds on Wednesday, March 13 into Thursday. It seems appropriate for a storm that strong to have bomb in its name, but the word actually refers to a meteorological phenomenon and not the cyclone's explosive intensity.

According to The Denver Post, the bomb in bomb cyclone stands for bombogenesis. Bombogenesis occurs when a non-tropical storm experiences at least a 24 millibar (the unit used to measure barometric pressure) drop within 24 hours. Low pressure makes for intense storms, so a bomb cyclone is a system that's built up a significant amount strength in a short length of time.

This type of storm usually depends on the ocean or another large body of water for its power. During the winter, the relatively warm air coming off the ocean and the cold air above land can collide to create a sharp drop in atmospheric pressure. Also known as a winter hurricane, this effect has produced some of the worst snowstorms to ever hit the U.S.

The fact that this latest bomb cyclone has formed nowhere near the coast makes it even more remarkable. Rather, a warm, subtropical air mass and a cold, Arctic air mass crossed paths, creating the perfect conditions for a rare bombogenesis over the Rockies and Great Plains states.

Central U.S. residents in the bomb cyclone's path have taken great precautions ahead of the storm. Over 1000 flights have been canceled for Wednesday and schools throughout Colorado have closed.

[h/t The Denver Post]

Watch a Rare ‘Ice Tsunami’ Slam Lake Erie

Clean Lakes Alliance, Flickr // CC BY 2.0
Clean Lakes Alliance, Flickr // CC BY 2.0

A combination of freezing cold temperatures and high winds is creating an unusual phenomenon along Lake Erie. As KDKA reports, ice tsunamis are toppling onto lake shores, and many locals have been asked to stay inside and even evacuate their homes.

On February 24, 2019, the National Weather Service in Buffalo, New York issued a warning about dangerous wind gusts in the Lake Erie area. The service urged citizens to seek shelter indoors and avoid traveling if possible. Winds peaked at 74 mph earlier this week, the level of a Category 1 hurricane, and tore down trees and power lines throughout the region.

People who got close to Lake Erie during the windstorm witnessed a rare event known as an ice tsunami. When wind pushed ice on the lake's surface toward the retaining wall, the sheet broke apart and dumped massive ice chunks on the shore. The video below captures the phenomenon.

In some areas, the ice piles grew so large that roadways had to be closed. Residents of Hamburg, New York's Hoover Beach area were asked to voluntarily evacuate due to the encroaching ice.

Ice tsunamis, or ice shoves, are rare, but in some cases they can be life-threatening. In 2013, waves of ice shards from a Minnesota lake destroyed people's homes.

[h/t KDKA]

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