Nature Photos of the Week

April 13, 2007

 

Amazing Weather! Tornadoes!

 

Springtime in Oklahoma!

The above picture is of a "wall cloud." When you see one of these, you pretty much

know there is tornado weather coming. These wall clouds can be just a few miles long,

or MANY miles long; sometimes stretching across the entire edge of the State.

 

Notice the "surreal" look in the colors of things on the ground in all of these pictures.

This isn't due to the photography, but is just how it is with severe weather. The colors

of the trees, grass and sky take on a very odd hue. Get to know this "look" as it is an

indication of bad weather on its way.

 

You do not want to be in the path of this one!

Tornadoes that form from a supercell thunderstorm are the most common, and often the most dangerous. A supercell is a long-lived (greater than 1 hour) and highly organized storm

feeding off an updraft (a rising current of air) that is tilted and rotating. This rotating updraft,

as large as 10 miles in diameter and up to 50,000 feet tall - can be present as much as

20 to 60 minutes before a tornado forms. Scientists call this rotation a mesocyclone when

it is detected by Doppler radar. The tornado is a very small extension of this larger rotation.

Most large and violent tornadoes come from supercells.

 

A closer look.

 

This tornado has a massive wall cloud and looks to be very large and getting bigger.

Mobile Doppler radars can measure wind speeds in a tornado at ground level, the

strongest at 318 mph, on May 3, 1999 near Bridge Creek/Moore, Oklahoma.

 

On the ground! Movement can range from almost stationary to more than 60 mph.

A typical tornado travels at around 10-20 miles per hour.

 

You can see in the above picture the finger of the tornado coming down

(two or more actually). You will not always see the bottom of the tornado touching

the ground because wind is invisible, but you can see the debris stirred up from it.

The reason you can see the vortex higher up is due to water droplets contained within

this "condensation funnel."

You can see a finger of a tornado coming out of this formation above in the very top

of the picture, indicating the early horizontal rotation of air.

 

Most tornados in the Northern Hemisphere rotate counter clockwise, but not all.

As the sun sets, the fringes of the weather often produce the most amazing colors.

 

Lightning can be seen through the clouds as the sky darkens and the storm moves off.