|
|
|
|
Violent Tornadoes
Mon May 02, 2005
Listen in RealAudio 
Hi, I’m Bryan Yeaton, and this is The Weather Notebook. The United States, especially
the Midwest, is the perfect place for brewing powerful, violent tornadoes. But do the
conditions there exist elsewhere on the planet. Dr. Harold Brooks at the National
Severe Storms Lab in Norman, Oklahoma, has been looking into just that.
For violent tornadoes to form, Brooks says that in addition to warm moist air at the
surface, you need cold dry air aloft to cap off the storm, just like the air coming off the
Rocky Mountains.
HB: If we put the warm moist air underneath the cold dry air we have another thing that
occurs in the United States and that's the air at low levels flowing out of the south and
the air at mid-level of the atmosphere say at 10,000 feet above the ground is flowing
out of the west and that change of direction with height of the winds is the kind of thing
we want to see to make those storms rotate. If the storms rotate they're much more
likely to produce tornadoes.
But there are higher, colder mountains on the planet. However, Brooks says that
orientation is vital for the Rockies.
HB: If you compare them to something like the Himalayas—that are higher than the
Rockies—it's very easy for air to flow around the Himalayas. In the central United
States there's essentially nowhere for air aloft, say 10 to 30,000 feet, to have not spend
time over the Rocky Mountains.
Many researchers think similar conditions may be found in Bangladesh, but Brooks
thinks another location with capping potential, is overlooked.
HB: I think most likely if we were going to find a second best location after the central
United States for making tornadoes, is probably southeastern Brazil and northern
Argentina.
The Weather Notebook is funded by Subaru of America.
|
|
