Here's how to watch out for storms during hurricane season

Storm surge and flooding are the greatest threats to Corpus Christi in a hurricane. Kirsten Crow/Caller-Times, Kirsten Crow/Caller-Times

The Atlantic side of the U.S. will most likely see a near-normal hurricane season with nine to 15 named storms, according to a new federal report.

Under that forecast, four to eight systems would become hurricanes, and two to four of those major, the National Oceanic and Atmospheric Administration said Thursday.

The prediction carries a weight of 40 percent, with a 30 percent chance each of an above-average and lower-than-average season.

It’s a question John Metz hears every year: how many hurricanes will churn out of the Gulf?

But seasonal outlooks shouldn’t be the focus, said Metz, meteorologist-in-charge of Corpus Christi’s National Weather Service office.

“It doesn’t tell us the most important thing – if we’re going to have a hurricane or not,” he said.

The season starts June 1 and continues through Nov. 30.

Here are some of the things you need to watch.

What is the biggest threat in a hurricane?

Hands-down, it’s not the wind. It’s the water.

About 80 percent of direct hurricane fatalities are attributed to flooding, according to the weather service — and half of all storm-related deaths stem from rising storm surge, when water is pushed from the ocean inland.

Do you live in a storm surge zone? This map can help

That’s why the National Weather Service in recent years rolled out new advisories: a watch being issued 48 hours before there is potential for storm surge of three feet and higher, and a warning issued 36 hours before it is expected surge will reach three feet and higher.

How do I calculate risk?

A 20 percent chance of a hurricane strike within five days may not seem alarming.

But a better way to look at it is a one-in-five chance of being impacted by a life-changing storm, Metz said.

The risk of an extreme event, even at lower probabilities, is significant, he said.

“We want you to take that seriously,” Metz said. “That is a big deal.”

Monitoring the forecasts means also considering that the threat of a storm can extend far beyond the coastline. Even residents who evacuate inland need to be prepared, Metz said.

What do the categories mean?

Storm categories label wind speeds.

Tropical storm: Between 39 and 73 mph
Category 1: 74 – 95 mph
Category 2: 96 – 110 mph
Category 3: 111 – 129 mph
Category 4: 130 -156 mph

They do not measure potential destruction from rain and surge, or the risks that come after a storm such as life-threatening lost access to medical care.

What do the advisories mean?

Hurricane watches are issued 48 hours before it is possible for a system to reach tropical storm speeds, and warnings are issued 36 hours before a storm is expected to exceed 73 mph.

In addition to the storm surge advisories, the NWS also has an extreme wind advisory.

Those are issued two hours or less before winds of at least 115 mph are expected.

They should be treated like a tornado is approaching, Metz said.