Do tornados hit the top of hills?

Question

I live in a mobile home park(in Iowa) that is at the very top of a hill. My son says that tornados never hit the top of hills. I think that is ridiculous. Is he correct? We have severe weather coming. Its an upscale park. Homes run between 60 and 180,000 and have great ties downs.. but still. We do have a shelter . I was just curious about his theory.

Answer 1

they don't  i live in NE and we never get em bc there are so many hills and mountains....

Answer 2

Yes, tornadoes can hit the tops of hills. Tornadoes have even been known to traverse across the sides of mountains and remain mainly intact. So your son is incorrect, tornadoes can and do hit the tops of hills.

This is from the National Severe Storm Laboratory:

Do rocks, hills, or trees increase or decrease the wind speeds in a tornado?

-Unfortunately, there is no clear answer. Both observations (of real tornadoes), computer simulations, and laboratory studies (in tornado vortex chambers) have shown that the "surface roughness", i.e., the measure of how disrupted the wind near the ground is by objects such as dirt, rocks, hills, trees, and even houses, can either increase or decrease the wind speeds in a tornado. How can trees increase the wind speeds? Well, the strongest winds in a tornado occur when air from outside the tornado can flow closest to the center of the vortex. The conservation of angular momentum, e.g., the rotation in the air, requires that as the air flows toward the center of the tornado (as it spirals in) its rotation must increase. Depending on the configuration of the airflow outside of the tornado, sometimes there is not ENOUGH "inflow" toward the center, and so blobs of air outside the tornado do not get very close to the center of rotation before they are lifted upward off the ground. In this case, INCREASING the surface roughness helps get these blobs of air closer to the center of the tornado, where they rotate even faster than before. So occasionally we see in tornado videos the vortex increasing in intensity when it travels from one type of ground surface (say a field) into a grove of trees or a housing subdivision. It does not always happen, but often enough that we are aware of it. This is a case where "friction", which people normally think of slowing things down, actually speeds them up!

http://www.nssl.noaa.gov/primer/tornado/...

Answer 3

Yes, tornadoes can hit the tops of hills. Tornadoes have even been known to traverse across the sides of mountains and remain mainly intact. So your son is incorrect, tornadoes can and do hit the tops of hills.

This is from the National Severe Storm Laboratory:

Do rocks, hills, or trees increase or decrease the wind speeds in a tornado?

-Unfortunately, there is no clear answer. Both observations (of real tornadoes), computer simulations, and laboratory studies (in tornado vortex chambers) have shown that the "surface roughness", i.e., the measure of how disrupted the wind near the ground is by objects such as dirt, rocks, hills, trees, and even houses, can either increase or decrease the wind speeds in a tornado. How can trees increase the wind speeds? Well, the strongest winds in a tornado occur when air from outside the tornado can flow closest to the center of the vortex. The conservation of angular momentum, e.g., the rotation in the air, requires that as the air flows toward the center of the tornado (as it spirals in) its rotation must increase. Depending on the configuration of the airflow outside of the tornado, sometimes there is not ENOUGH "inflow" toward the center, and so blobs of air outside the tornado do not get very close to the center of rotation before they are lifted upward off the ground. In this case, INCREASING the surface roughness helps get these blobs of air closer to the center of the tornado, where they rotate even faster than before. So occasionally we see in tornado videos the vortex increasing in intensity when it travels from one type of ground surface (say a field) into a grove of trees or a housing subdivision. It does not always happen, but often enough that we are aware of it. This is a case where "friction", which people normally think of slowing things down, actually speeds them up!

http://www.nssl.noaa.gov/primer/tornado/...

Answer 4

Tornadoes can hit the top of hills and mountains they are mostly common around the Rockies and Colorado because of its hilly and mountainous terrain.