This article first appeared in the St. Louis Beacon, April 03, 2011 - Sandra Smith wasn't that worried. Except for the wail of the siren, things were quiet.
"It was eerily calm outside," recalled the Crestwood resident. "It really wasn't windy."
Suddenly Smith's husband David yelled for the family to get to the basement as sheets of rain pelted the house. The couple, their two children and their disabled daughter's nurse hadn't even gotten all the way down the stairs when they heard a deafening roar and crash from behind.
When they emerged minutes later, it was to an incredible scene. Large limbs were speared like arrows through the dining room ceiling. Big cracks were visible above the breakfast area and the living room windows were shattered. Glass was not just scattered, but embedded in walls and furniture.
Most notable however, was the massive 60-foot pine tree which had been uprooted whole and deposited on their kitchen. The Smiths could now look up and see sky through their roof. Outside, a second tree had crushed the family minivan.
Sandra Smith had heard the sirens many times but never been in a tornado before.
"I always thought you would get some kind of sense that it was getting very windy outside," she said. "But it was dead still. It just came from out of nowhere."
Tornado Alley
The tornado the Smiths experienced was an EF3, meaning a vortex packing winds of up to 165 miles per hour. It was one of several spawned by a major storm system that moved through the area on New Year's Eve flattening homes and businesses and leaving a trail of destruction across the state.
On average, Missouri sees about 32 tornadoes - and four deaths - every year, most of them in the spring when warm, moist air from the Gulf of Mexico meets with cold fronts blasting in from the Upper Great Plains. The number can vary widely however. In 2006, a record-setting 102 twisters ripped across the state, which lies in Tornado Alley, an ill-defined central region of the United States that sees more funnel clouds than any other place on Earth.
"It's simply where we are on the planet," said Jim Kramper, warning coordination meteorologist with the National Weather Service. "We are in a perfect spot for two different types of air masses to collide."
A particular type of thunderstorm, known as a supercell, is responsible for most tornadoes. The funnels, which tend to form in the storm's southwest quadrant, are thought to be the result of wind shear between various levels of the atmosphere. These differing wind speeds can cause air caught in the storm's warm, moist updraft to rotate. If the rotation is intense enough, becomes vertically oriented and drops from the sky, the results can be deadly.
As might befit something that inspires such terror, there are a lot of myths about tornados.
For one thing, they are not always visible, particularly in the early stages. At its heart, a twister is simply a swirling current of air. Its gray or dark appearance is due to dust and debris though further up the whirlwind can sometimes appear as a funnel cloud. In some circumstances precipitation can cloak the event almost entirely resulting in a very elusive and dangerous "rain-wrapped" tornado.
Meanwhile, most tornado folklore is only partially true. Green skies and hail don't always herald the phenomenon. Kramper said both sometimes occur with strong storms and hence have become associated with tornadoes in the public mind.
The twister's legendary capriciousness has also inspired misnomers.
"A lot of people say a tornado hops, skips or jumps over objects," Kramper said. "I prefer to call it more of a weakening/strengthening pattern. The rotating air is there. It's just a matter of whether it is strong enough at any given instant to cause damage."
Getting the Word Out
The warning the Smiths got, about 10-13 minutes between siren and twister, was typical, said Kramper, though some alerts can be significantly longer, as much as half an hour. Regardless, it's a vast improvement over warning times two decades ago.
That's because often there weren't any. Previous to the early 1990s, the primary alert system was based on an antiquated post-WW II radar that could do little to distinguish a tornado from the surrounding storm. Only a telltale "hook echo" caused by rain wrapping around the funnel, a characteristic some twisters didn't even have, gave the radar operator an indication of danger. Most tornado warnings were the result of reports from trained spotters or the general public.
That era ended with the introduction of Doppler technology that could effectively measure different wind velocities at different elevations within the storm allowing meteorologists to recognize potential tornadoes much more easily. Still, it's not a perfect system. Forecasters remain blind to much of what happens below about 3,000 feet.
"That's what we're still lacking," said Kramper. "We can't see the rotation that you and I would consider the tornado, that is, the rotating air from the cloud base down to the ground. What we can see is rotation higher up and it will vary depending on the distance from the radar."
That's one of the reasons the National Weather Service still relies on human eyes on the ground. Roughly 4,000 spotters are spread across the 46-county area covered by the St. Louis office, though Kramper said that only about 25 to 30 percent report on a regular basis. The NWS offers free classes to those who would like to become involved.
"We do work a lot with public service organizations," he said. "Especially in rural areas, we work a lot with volunteer fire departments. They tend to be very active in this. We also work with the amateur radio community."
Awareness has improved over time. Nicole Holtgrefe who deals with preparedness, sales and outreach for the local American Red Cross, said that knowledge has increased and homes are now built sturdier. St. Louisans also benefit from the popularity of basements in the Midwest.
Even old technologies like radio are better.
"It used to be that people wouldn't buy NOAA weather radios because anytime there was any type of emergency anywhere, they would go off and drive people crazy," she said. "Now the great thing is that you can program them to your zip code and it only goes off if something is happening in your area."
Phased Array
Kramper said that the next generation of radar is on the way though its time of arrival remains as uncertain as that of the tornadoes it is designed to predict.
New phased array systems will eventually replace the two-decade-old Doppler setup, providing better resolution and quicker response by replacing the adjustable rotating dish that tilts up and down to see various slices of the atmosphere with an arrangement of fixed radars that beam pulses in all directions at once, cutting scan times that would normally take several minutes to only 20 or 30 seconds.
They are saying it may be possible that we could routinely get tornado warnings up to 30 or 40 minutes in advance," Kramper said. "That would be incredible if it could be done."
But a different kind of destructive whirlwind, the one that struck the economy, has made the going difficult. There is no estimate on when the new stations might be installed, Kramper said.
"The big issue will be money," he noted. "Will we be getting a new system anytime soon? Probably not. Given the budget situation we have now, it doesn't look promising."
In the meantime, he said the best offense is a good defense.
"We're trying to get information out to the public but that's all the National Weather Service can do," he said. "The bottom line is that the individual person has to pay attention to what's going on. They have to make that final decision. Am I in danger?"
It's a question the Smiths know all too well. They now live in temporary quarters as $45,000 worth of damage to their home, which was insured, is put right.
Other damage is harder to see. Their 5-year-old son, now in counseling over the experience, doesn't like to be left alone in rooms.
"He's still traumatized by the whole thing," said Sandra Smith. "He still talks about it and doesn't want to go back into the house."
She advises others to heed tornado warnings, even if the skies appear unthreatening. It's a lesson her family won't forget.
"I'd always thought that when you hear sirens, if it starts to look bad out, we'll go downstairs," she said. "I never realized it could look totally fine and then - bam."
David Baugher is a freelance writer.