hills and tornadoes

[Lori Meyer]

My brother-in-law is certain that hills and tornadoes are not compatible with one another. He studied meteorology a bit in the air force; however, he does not know what he is talking about. We had lots of fun going back and forth with one another on the subject. The only picture I could find including hills and a tornado was in Alaska and the photo appears to only be a funnel; although, it was reported as a tornado at one point. If anyone has a photo, or knows where one might be, including a tornado in a hilly region, I would be very thankful.

 

[Steve_Stuck]

http://tornado.sfsu.edu/RockwellPassTornado/

 

[GPhillips]

Not a picture, but a study done by SPC personnel on tornadoes in the Big Horn mountains.

http://www.spc.noaa.gov/publications/evans/bighorns.htm

 

[Dave Kaplow]

I remember many years ago a tornado destroyed a local ski area. This happened at Mohawk Mountain in northern CT, I think sometime back in the eighties. Historically there have been numerous tornadoes in this area, including some very violent ones. In fact I consider the area around the Berkshires, a mountainous area centered in western MA, to be something of a mini-alley. Some tornado track maps I've seen indicate this area gets hit almost as often as many places in the heart of tornado alley (see for example Howard Bluestein's book Tornado Alley, or the map in the April 2004 issue of National Geographic). Clearly, hilly terrain does nothing to suppress tornado formation.

 

[Mike Peregrine]

Take him along the path of the 05/04/03 tornadoes ... the tornado that crossed near the speedway went down the bluffs on the Kansas side, over the Missouri River, up the river bluffs across from Riverside and up and down some very hilly areas. Johnny Roelands has some good video of the hilly terrain those tornadoes crossed.

The November, 2002 outbreak across Tennessee also occurred in a mountainous area on the east side of the state. Towns like Mossy Grove, TN - that had previously felt totally protected from storms - took a very heavy hit that day, with multiple fatalities. http://www.weather.gov/om/assessments/pdfs/veteran.pdf

 

[Jeremy Lemanski]

June 8th 1966 Topeka Kansas. An F5 tornado struck the city, and while doing so, went directly over Burnetts Mound, which, according to the legend, would protect the city from tornadoes.

 

[Bart_Comstock]

Also lets not forget the F2 tornado that hit Salt Lake City on August 12th, 1999.

And the tornados that hit my county this year on March 12th, crossed several valleys and climd a few hill sides.

 

[Angie Norris]

Mossy Grove is an excellent example. Some other east TN tornado activity was the F1 near Knoxville, TN on April 3 1974 that formed on top of a ridge, dropped into the valley, destroyed a trailer park, and went up the ridge on the opposite side of the valley ( I was on the disaster response team for that event). There was also the east TN outbreak Feb 21, 1993 with several tornadoes that followed ridgelines and dropped into valleys.
Angie

 

[Brandon Clement]

This should help your case.

 

[Brian Emfinger]

As someone who lives in the Ozarks of Arkansas i have also come to several conclusions about this.

I definately think that mtns have the ability to disrupt or even destroy weak tornadoes. Since the majority of tornadoes are weak this can definately explain why some of the mountainous areas of the country seem to have fewer reported tornadoes. (of course this can also be explained by fewer people living in the mountains to report them, but i am not sure this is such a valid argument as used to be since the nws goes out and surveys any areas of reported damage)

I dont think a mtn will make much of a difference for stronger tornadoes (at least initially).

I also think the influence of a mtn or mtn range will affect the whole lower level flow of the storm. I have seen several supercells (not sure if they dropped tornadoes but they were torn warned) that have made their way out of Oklahoma into the mountainous regions of the Ouachita Mtn and they quickly died. Of course the could also be attributed to the climatologically more favorable storm conditions that tend to exist just west into Oklahoma. I have also seen storms that have followed valleys and didnt seem to be affected at all. I used to live in Waldron, AR. Tall east-west mtns (2000-2500) are to the north and to the south stretching about 35 miles west and 20 or so miles east. Most of the time we had severe weather (hail, strong winds) the storms were moving nearly directly from west to east along the path of the valley. And of course there are exceptions with some storms moving through mtns not being affected and some moving through valleys weakening but for the most part i dont think supercellular storms like mtns...especially when they are relatively weak or already weakening.

I also think its possible for mtns to enhance storms and tornado potential. Polk county (Mena) Arkansas seems to have a higher occurance of tornadoes that surrounding counties and Polk county is extremly mountainous.

I am going somewhat off topic now but anyway hope that helps

 

[Bart_Comstock]

Well I also agree with Brian. In fact when I was on a chase last year (just west of Springfield, Colorado) me and the guys I was chasing with, noted that storms would begin to "spin up" as the passed by a mesa, causeing them to rotate. Below is a picture of a wall cloud that one of the cells produced, as the cell approached the mesa it started to rotate and then once it cleared the mesa the cells rotation weekend and it lost it' wall cloud as well as began to weaken. This was the case for about 3 other cells that followed the same track. (A bit off topic, but the cell just north of us put down a nice big wedge shortly after the wall cloud shown below dissipated.)

(you can see the messa behind the hill that the wall cloud is over)

 

[Michael Thompson]

Australia's strongest tornado occurred over very hilly, and heavily forested country. The tornado was rated at least F4, but many believe it was an F5, almost unheard of outside the US.

http://www.psychcentral.com/psypsych/Buladelah_Tornado

The countryside is the eastern slopes of the Dividing Range, the tornado was supposed to have destroyed over 1 million trees. Trees in Buladelah are not small, New South Wales' tallest tree is in Buladelah at around 80m ( 200ft plus ) high. The area is thickly forested with tall timber and rainforest gulleys.

The link below has a picture of the tree and the area - at bery bottom of link page

http://www.mdavid.com.au/trees/bigtrees.html

The area appears to produce a decent supercell or two every year.

 

[Pat Lawrence]

Hi Lori,

This report may lend some credence to those who believe tornadic circulations are disrupted by “hillyâ€￾ terrain:

THE TORNADO CONTINUED TO ABOUT 1 MILE EAST OF VIOLA WHERE THE DAMAGE PATH THEN BROKE AS IT ENCOUNTERED A STEEP BLUFF...AND THE PATH THEN BECAME MORE SPORADIC.
http://www.crh.noaa.gov/arx/events/aug182005_tors.php

Scroll down to “Viola, Vernon County, WI: 4:05 pm - 4:40 pmâ€￾ for the remainder of the event summary.

While I don’t believe this summary is in any way suggesting this happens often, it would appear that terrain may have disrupted this particular, somewhat weak, tornado.

Pat

PS This was the same system that produced the Stoughton, WI F3 last year.

 

[Lori Meyer]

Thank you all for the ammunition. I did mention that weak tornadoes may be disrupted by hilly terrain; however, I have read that strong tornadoes can actually gain strength when entering a valley between hills.

 

[Andy Wehrle]

Hi Lori,

This report may lend some credence to those who believe tornadic circulations are disrupted by “hillyâ€￾ terrain:

THE TORNADO CONTINUED TO ABOUT 1 MILE EAST OF VIOLA WHERE THE DAMAGE PATH THEN BROKE AS IT ENCOUNTERED A STEEP BLUFF...AND THE PATH THEN BECAME MORE SPORADIC.
http://www.crh.noaa.gov/arx/events/aug182005_tors.php

Scroll down to “Viola, Vernon County, WI: 4:05 pm - 4:40 pmâ€￾ for the remainder of the event summary.

While I don’t believe this summary is in any way suggesting this happens often, it would appear that terrain may have disrupted this particular, somewhat weak, tornado.

Pat

PS This was the same system that produced the Stoughton, WI F3 last year.
[/b]

...and most of my neighborhood is located on a hill, didn't seem to do us much good. My mother took this picture of one of the houses:

In fact, the whole vicinity is rather hilly: