An update on tropical storms terminology
AUSTIN (KXAN) -- The latest hurricane to roam the Atlantic was not expected to make landfall on the United States east coast. But, that did not mean that Hurricane Ernesto would not affect the eastern seaboard through other means.
When KXAN meteorologists talk about possible outcomes related to what a hurricane or tropical storm does, there is certain terminology used to say more than what the winds are or the direction a storm is moving.
It's pretty easy to figure out what a hurricane watch and hurricane warning mean. A hurricane watch means that hurricane conditions are possible within a specified area. It's when winds reach 74 mph or higher. The watch is issued 48 hours before the anticipated onset of tropical storm force winds.
A hurricane warning is issued within 36 hours. The conditions that cause a warning to be issued are those same 74+ mph winds, storm surge, and coastal/river flooding. The NWS issues warnings to give people time to prepare and evacuate if directed by local officials.
Hurricane Ernesto made landfall early Saturday morning on the west side of Bermuda. That put the rest of the island in the northeast quadrant, or the worst quadrant of the storm. The northeast quadrant is the worst because it's the direction the storm is moving and where the strongest winds occur, along with the worst storm surge. It's also known as the "dirty side".
The United States did not have to worry about that this time but did when Hurricane Beryl made its landfall in Texas and Debby in Florida. But there were other concerns related to Ernesto that were cause for concern.
The first concern was RIP CURRENTS. We mention that occasionally when discussing hurricanes. A rip current is a narrow, powerful channel of water flowing away from the shore. They can be found along the Atlantic, Great Lakes, Gulf of Mexico, and Pacific. They'll form at breaks in sandbars and near structures like piers and jetties.
They move fast, faster than an Olympic swimmer, up to 8 feet per second. They can get as wide as 90 feet and extend up to 3,000 feet offshore when conditions are right. They're capable of moving sand and marine life.
They're dangerous. It is estimated that rip currents cause 100 deaths each year in the United States, which is why lifeguards tell people to stay out of the water when rip currents are at hand.
Another concern for the eastern seaboard was SWELLS. These are large waves created by the ocean's energy from hurricane winds miles away. The longer and stronger the wind flows, the more energy is transferred and the larger the swell. They can be dangerous as they cause rip currents.
Swells cause more discomfort than anything in deep water. However, in shallow water, it can produce breaking waves strong enough to capsize boats.
Perhaps the one we discuss most is STORM SURGE. It's an unusual increase in the water level during a storm above the predicted astronomical tide. The storm's winds push a large amount of water onshore. It's measured as the height of the water above the normal tide.
Storm surge is often the greatest threat to life and property. History tells us that it's the leading cause of hurricane-related fatalities in our country. Saltwater from storm surges can contaminate freshwater aquifers, lakes, and rivers making the water unsafe to drink, thus causing additional endangerment to plants and wildlife.
By the way, storm surges were not going to be a factor in the weather on the East Coast during Ernesto.
You'll hear more about these now that we have started the peak of the hurricane season. It peaks on Sept. 10.