Monday, June 02, 2014

Weather Channel "Tornado Alley" simulates destruction in Washington DC and Miami FL

The Weather Channel has treated us, in its “Tornado Alley” series, simulations of what could happen if monster tornadoes hit Washington DC and then Miami, FL
The DC tornado supposes a strong cold front in April, leading to the form of an EF4 tornado near the Pentagon, hitting the Jefferson Memorial, Lincoln Memorial, White House, and Capitol.  Because most tornadoes move SW to NE, that track sounds even more unlikely than an EF4.  The storm divides into three funnels, and then combines again to an EF5, and eventually hits the Capitol with 320 mph winds, the strongest theoretically possible.  The major monuments all survive, but the Capitol dome is toppled.
Thousands of people become casualties to flying debris, including cranes.  A gas explosion and fireball is also possible.
Doug Kammerer, of NBC Channel 4 in Washington, appears. 
The documentary says that mountains do not prevent tornadoes, and cites one that climbed up a mountain in Yellowstone, and even one on Pikes Peak.
However, severe thunderstorms in the DC area do tend to be more common about 30 miles NW of the city (coming through Harpers Ferry Gap), or about 40 miles to the SE, near where the Potomac and Cheaspeake Bay meet.  The main reason why tornadoes are less common in the mid Atlantic is that the area is farther way from the greatest clash of warm and cold air in spring and fall, in the Great Plains and some of the southeast. 
The documentary mentions an unusual F4 tornado in Frostburg, MD, in the Alleghenies, in June 1998, and one in La Plata MD in April 2002.  The unusual 1998 outbreak is described here in Wikipedia (link) and has not recurred despite climate change.  There was a tornado outbreak in the DC area September 24, 2001 (less than two weeks after 9/11) that became most intense (reaching F3 and multiple vortices) NE of the city in suburban Maryland, including College Park (link) .  A tornado may have helped defeat the British when they tried to invade Washington DC in 1814, during the War of 1812  (Post coverage ).
A second documentary depicts an EF5 tornado in Miami.  It points out that the greatest wind speeds may be about 40 feet off the ground.  New building codes in Miami require carbonate layers in glass in lower floors.  The frames of the skyscrapers survive because they have “plasticity”.  A cruise ship in harbor is destroyed.
Rebuilding after an event like either of these would be much more challenging than in a small town. 
Should houses be built with steel frames?
After such an event, I don't even know if rebuilding would be practical for me and if I would be able to return.   In my case, it's complicated.   

Picture: Damage on Gloster street in a commercial area of Tupelo, MS, four weeks after the April 28, 2014 F3 torndao; personal visit 

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