A medevac helicopter lies in ruins beside St. John’s Regional Medical Center following a direct hit by an EF-5 tornado on Joplin, Missouri May 22, 2011 (AP/Mark Schiefelbein)

One year ago tomorrow, Joplin, Missouri was impacted by a most-feared EF-5 tornado with winds over 200 mph. As if these events are not merciless enough on their face, this one spun up just as it was entering the city on a storm with no previous tornadoes. After laying waste to neighborhoods and lives, it weakened significantly just outside the city limits.

When the early-evening storm was through, and skies began to clear, the devastation left behindwas brutally apparent. 161 people would eventually be confirmed dead, with over 7,000 homes and 500 businesses destroyed, along with other public buildings like schools and hospitals.

The violent Joplin tornado strikes the city, by TornadoAlleyVideo.

Following a break in major tornado activity after the April 27, 2011 event, things started to ramp back up in the days before May 22, 2011. Topeka, Kansas had a tornado scare just the day prior.

On May 22, the outlook from the Storm Prediction Center indicated a “moderate risk” from Wisconsin back to northeast Oklahoma. In severe-weather speak, that means it was the type of day seen maybe a dozen times in an active year. A day to pay extra attention, but perhaps not one to scream from the rooftop of impending doom.

While the day did not seem overly notable at the get go from a historic perspective, Joplin was included in an elevated risk for strong (EF-2 through EF-5) tornadoes, though places to its northeast through the upper Midwest stood an arguably higher threat for widespread tornadic activity.

The heaviest concentration of storm reports from May 22, 2011. Red are tornado reports.

Not to mention an EF-5 is about a 0.1% event when it comes to all tornado activity.

So, why did it happen?

A strong upper-level low-pressure system, which aided twisting in the atmosphere and brought cold air aloft for explosive thunderstorm development, was the driver of the larger event on May 22, 2011. But it was a fairly compact system. Not the type that tends to lead to multiple violent tornadoes over a large area, like seen on April 27. As noted, an elevated threat, but not an extreme one -- so it seemed.

The difference maker may have been CAPE (see a previous discussion on CAPE here). This potential energy for thunderstorms was close to off the charts in the Joplin area that day. Additionally, storm relative helicity (SRH) -- a measure of the spin needed for tornado development -- increased markedly throughout the afternoon. Perhaps in response to weak surface low pressure development in Kansas to the south of the parent low.

Supercell storms began to develop in the mid-afternoon along a line slicing through Missouri and back into Kansas. The eventual Joplin cell (or rather, group of cells) became the dominant force at the southern end of the line. Because it sat on the nose of the highest instability in the air mass where thunderstorms were firing, the group of cells had a seemingly endless supply of fuel.

As the supercell cluster approached Joplin after 5 p.m., reports of funnel clouds were already fairly numerous, but no tornado touchdowns were noted. However, as the dominant storm approached from the southwest, radar velocity signatures rapidly tightened up, showing a potential extreme event in the making.

By 5:41 p.m., the tornado was on the ground. It rapidly became a large and violent rain-wrapped monster that crawled through the heart of the city, leaving massive ruins in its wake. Sadly, an EF-5 tornado through heavily populated areas puts too many lives in the way of something that is hard to survive above ground. In this case, the worst modern tornado event in modern history unfolded.

Joplin has recovered significantly, if irregularly, in the year that’s passed since the tornado.

Reconstruction has progressed rapidly in spots, particularly businesses like those along the Range Line commercial zone. It was previously Joplin’s busiest area for business, and also one of the hardest hit in the city on May 22, 2011. 49 of the 71 businesses impacted there are back up and running. Citywide, at least 429 of the 545 destroyed and damaged businesses are open or in the process of reopening.

In one particular sign of hope, St. John’s Hospital, perhaps one of the most easily recognizable symbols from the Joplin tragedy has already been temporarily replaced. The new Mercy Hospital Joplin‘s 150,000 square foot facility is considerably stronger than its predecessor and was built quickly through pre-fabricated material.

Many housing lots that used to contain homes, however, remain empty and hundreds of people still have no place to live. Additionally, the roughly 90% of total apartments available before the tornado that were wiped out have not rebounded quickly. That has made finding affordable rental options difficult. But the task was large, seen in the fact that National Guard remain on the scene, and it’s getting done.

UAE Ambassador Yousef Al Otaiba perhaps recently summed up the story of Joplin as well as anyone could when he said, “The resilience of the people of Joplin is an inspiration to the entire world.”

See also...

Joplin Tornado Anniversary

The Joplin tornado environment - poor visibility with large shear & instability

An additional look at the Joplin tornado, after the assessment report

One month later: a timeline of the May 22 tornado