El Reno Tornado Controversy: “Drive away” or shelter “above ground?”

Tornado Tales

The recent swarm of tornadoes in Oklahoma is still making headline news, and generating controversy and questions about the best advice for surviving tornadoes.

Let's face it, once an EF-5 tornado is heading at you...you are now in the position of making the best choice from some potentially bad options.

One broadcast meteorologist in Oklahoma City is catching flak for his advice to "drive south" away from the tornado in El Reno last Friday.

Whether it was rush hour, a flock of storm chasers... or people trying to flee the tornado, it didn't take long for major roads and freeways in Oklahoma City to turn into parking lots Friday evening. Thousands of motorists were literally sitting ducks on I-35 and I-40 as the widest tornado in U.S. history tore a 2.6 mile wide path...with 294 mph winds toward them.

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I feel for Mike Morgan at KFOR. Anyone who has been under the real time pressure of broadcasting potentially life saving advice during a tornado emergency knows that it's easy to say a few words you wish you could have back.

So what is the best advice for surviving a tornado?

The topic came up at Tuesday's Twin Cities Integrated Weather Team meeting in Minneapolis.

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What's an "Integrated Weather Team?"

There are many things that literally cause meteorologists and emergency managers to lose sleep. One of the biggest is what we will do when the next large and potentially deadly tornado bears down on the Twin Cities. Or how we will cope with...and adapt to the increase in extreme rainfall events in Minnesota as our climate goes through a "phase shift."

That's why a dedicated group of emergency managers, broadcast professionals, NWS and broadcast meteorologists gathered Tuesday at the Minneapolis Emergency Operations Center for the second annual Twin Cities Integrated Warning Team meeting.

How do we best communicate the sudden, dynamic and fluid threat of severe weather or other emergency situations as they evolve in real time? What role does broadcast TV & radio, smart phones...and social media play in the critical minutes before and during a tornado strike on a major city?

It's what keeps us up at night...staying ready for the rare, but devastatingly catastrophic events like those that have ravaged Oklahoma recently.

Here are a few notes from the meeting.

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Mark Seeley University of Minnesota & MPR

My MPR colleague Dr. Mark Seeley gave us some astounding benchmarks on just how rapidly Minnesota's climate is shifting, and how extreme weather in Minnesota is becoming the new normal.

-Weather Whiplash: The record warmth of March 2012 was the "most anomalous month in Minnesota and USA climate history" Fast forward to spring of 2013, and Minnesota is living through one of the coldest and wettest springs on record. This kind of year to year "weather whiplash" is unprecedented in Minnesota's climate record.

-On the need to adapt: Minnesota's infrastructure is built upon older perceptions of climate behavior that no longer hold true. We need to adapt our infrastructure to the new climate reality...which include more heat waves, tropical humidity episodes (70F to 80F+ dew points) in summer and excessive rainfall events.

-On changing rainfall patterns: A greater percentage of Minnesota's annual precipitation is coming from summer thunderstorms...and the extreme rainfall they produce. The gentle soaking rains of our youth are fewer and farther between. That is promoting a cycle of flood...and drought in Minnesota. Twice in the past 6 years several counties in Minnesota were declared in flood...and drought at the same moment in time.

The "new normal" in Minnesota's changing climate includes an "amplified thunderstorm signature" meaning more of our rainfall is coming in the form of heavy downpours.

Daniel Dix - Sr. Meteorologist- The Weather Channel

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-Moore, Oklahoma Tornado: Dan is a Minnesota native, and part of a Weather Channel crew that arrived on scene just after the deadly Moore, Oklahoma tornado on May 20th.

-One of the remarkable things Dan and the TWC crew found is that the vast majority of those in Moore who sheltered in homes "above ground" in the EF-5 twister actually survived. Some wore helmets, some were injured...but Dan told me personally well over 50% of those who could not get below ground survived.

What Dan and his team found runs contrary to NWS "enhanced language" in the new "storm based warnings" that called the tornado "unsurvivable if you are above ground."

The moral of the story here?

Even if you don't have a basement or below ground storm shelter...you are better off by "sheltering in place" in an interior closet or bathroom inside your home...rather than trying to escape a rapidly approaching tornado by car.

Kenny Blumenfeld - UM (urban) Tornado Researcher

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-On Minnesota's changing winters: The vast majority of the past 30 winters in Minnesota fall into the milder than average...lower snowfall portion of the distribution. The number of sub-zero days are falling rapidly...and the occurrence of -20F to -30F or colder temps in the Twin Cities is rare now...the exception. Urban heat island does not play a role here...as locations where temps have been observed historically (including downtown Minneapolis) have always been urbanized.

-On severe storm and tornado "recurrence" in the Twin Cities:

Severe winds and tornadoes happen more frequently historically then many think in the Twin Cities.

Some "recurrence intervals" for metro storms:

EF2-"killer tornadoes" - every 2-3 years

64 knot winds (hurricane force) - every 1-1.5 years

2" hail - every 1.5 years

4" rainfall events - every year

EF4-5 tornadoes - every 12.5 years

80 knot winds ("blowdown type") - every 4.5 years

3" hail - every 7 years

8" rainfall - every 10 years

These extreme weather events occur somewhere in a large area like the Twin Cities metro more often than you might think.

The purpose of the IWT is to do our best to be ready the next time they happen.

To be clear...here are the current best recommendations from NWS for tornado/severe storm safety. The Norman. Oklahoma NWS office has highlighted these after the recent events in Oklahoma.

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After the events in Oklahoma in recent weeks, I have a new appreciation for my sometimes musty...and potentially life saving "Minnesota basement."

Paul Huttner