Here's What You Need To Know About Hurricane Season In San Antonio
Hurricane season began this year on June 1. Forecasters with the National Weather Service expect an average Atlantic season with nine to 15 named storms, including four to eight hurricanes and two to four major hurricanes.
NWS forecaster Brett Williams predicted an average season because the wind shears created by El Niño are expected to cut through and destroy several of the tropical storms that will grow over the warm waters of the Gulf of Mexico.
Williams said the biggest threats to South Texas are heavy rains and flash flooding, especially if a Category 4 or 5 storm strikes the coast.
He said sustained winds up to 70 mph are possible deep into South Texas if a Category 4 or 5 hurricane were to hit the coast around Corpus Christi.
“Tropical storm-force winds on a big storm like that is not out of the question, especially for our southeastern counties,” Williams said.
The first three storm names will be Andrea, Barry and Chantal.
The season ends on November 30, and South Texas tends to see the worst tropical weather in August and September.
The deadliest and costliest storm to have originated in the tropics and arrive on San Antonio’s doorstep was in 1921.
NWS reported the remnants of a tropical storm that year caused flooding that damaged downtown, killed 51 residents and left behind $5 million in damage. Adjusted for inflation, the storm is still the most expensive in San Antonio history.
While the storm is nearly a century old, it left behind some very visible landmarks to prevent the future flooding of downtown San Antonio.
The 1921 flood spurred the construction of the Olmos Dam and the bypass channel through downtown San Antonio that would later become the River Walk.
Forecasters also said that in October 1998, two Pacific hurricanes, not Atlantic ones, caused deadly flooding in San Antonio. Heavy rains from Hurricanes Madeline and Lester unleashed torrents in the area that caused 11 deaths in Bexar County and $750 million in damage.
San Antonio, like Austin, is pressed up against the Hill Country, in what is known as flash flood alley and where flooded low-water crossings claim the most lives when motorists drive through them.
The weather service reports half of the flash flood fatalities in Texas occur in the I-35 corridor from San Antonio to Austin and into the Hill Country.
Nefi Garza, in charge of managing storm waters for the city’s Transportation and Capital Improvements Department, said there are 146 low-water crossings in Bexar County, which are monitored in a high-tech and joint way with the county.
“We have a computer system that we receive notification when water begins flowing and water begins rising, and it even tells us the moment when water goes over the road.”
Bexar County residents can monitor all the low-water crossings at bexarflood.org, where they can select the most dangerous low-water crossing near you to receive customized updates.
“You can actually click on one of those low-water crossings, and, if you are interested, you can actually subscribe to receive a test message or email when that low-water crossing is flooding.”
Garza said the city relies on crews to place barricades to keep motorists out of flooded low-water crossings.
He said the city has tried a couple of automated systems, where flashing lights come on and arm poles drop over a flooded road after a monitor detects rising water, but thieves targeted them.
“For some reason, people like stealing the lights off of them or stealing the actual poles, so we are constantly repairing those, and so we have gone away from that and we are actually phasing those out,” he said.
The Texas Department of Public Safety, just like NWS, reported most of the people killed in flooding are motorists who drive into flood water.
Sergeant Orlando Moreno of the local DPS office said it only takes a foot of water to sweep a 3,000-pound vehicle off a flooded road, and you can’t always trust the flood gauge on the side of the road to judge how deep the water is.
“When water is covering the road, you can’t see what is underneath that, so sometimes the road may be washed out below the water line and people feel like the water does not look very high and once they enter it, there is no road there and the car can become stuck and then as the water rises it gets carried off.”
Moreno said stay off the road when storms hit the city and make sure you are stocked up on a few days' supply of water and food in case the power is knocked out by flooding and high winds. He said have an evacuation plan and be familiar with evacuation routes in advance in case you are asked to get out by a government agency.
He said the disabled and elderly probably have special needs during evacuations, so keep them in mind too.
Many people also forgot to plan for their pets when Harvey hit in 2017.
“A lot of pets were left behind by necessity," he added, "and so it's important to keep them in mind when you are evacuating also.”
Moreno also said if you live in a flood-prone area make sure you buy flood insurance well in advance of potential flooding.
“There are a lot of times these flood policies have a 30-day waiting period before they even take effect,” he said.