Mustang Horses and Tornadoes
We began to think more seriously about an emergency plan for our mustangs after the severe weather outbreak in our area on March 2, 2012. The small Indiana towns of Henryville and Marysville, about 30 miles north of Louisville, were almost completely destroyed by an EF-4 tornado (Enhanced Fujita Scale).
The first part of this web page briefly discusses the formation of tornadoes during the February 28-March 3 storms across the Midwest and Southeast regions of the U.S. This is intended primarily for foreign visitors who makeup about 50% of the site traffic and are probably less familiar with tornadoes. About 80% of all tornadoes occur in the U.S.! Most U.S. horse owners have never experienced a tornado but are very aware of the violent nature and catastrophic effects of these storms through the media.
The second part focuses on our decision to allow our mustang horses free access to pastures during severe weather.
As shown in the weather map for March 2, tornadoes formed in the Midwest and Southeast when warm, moist and very humid air from the Gulf of Mexico came in contact with cold, dry air from the north along a strong jet stream.
The first part of this web page briefly discusses the formation of tornadoes during the February 28-March 3 storms across the Midwest and Southeast regions of the U.S. This is intended primarily for foreign visitors who makeup about 50% of the site traffic and are probably less familiar with tornadoes. About 80% of all tornadoes occur in the U.S.! Most U.S. horse owners have never experienced a tornado but are very aware of the violent nature and catastrophic effects of these storms through the media.
The second part focuses on our decision to allow our mustang horses free access to pastures during severe weather.
As shown in the weather map for March 2, tornadoes formed in the Midwest and Southeast when warm, moist and very humid air from the Gulf of Mexico came in contact with cold, dry air from the north along a strong jet stream.
This was an unusually warm day with record temperatures across the region. The less dense, warmer air rose above the colder air along the front creating updrafts of rotating thunderstorms called supercells, which can sometimes lead to the formation of tornadoes. The internal rotation of the thunderstorm, which is essential to the formation of a supercell, is caused by wind shear. To learn more about wind shear and supercells, refer to this article in the May-June 2011 issue of Weatherwise.
Supercells have a well defined rotation in Doppler radar images referred to as a mesocyclone. No doubt you have heard your local TV meteorologist talking about "rotation or circulation" in thunderstorms during tornado warnings. The most destructive tornadoes are usually associated with supercell thunderstorms whose radar signature is a characteristic "hook" pattern, reflecting the counterclockwise rotation of the mesocyclone (below).
Supercells have a well defined rotation in Doppler radar images referred to as a mesocyclone. No doubt you have heard your local TV meteorologist talking about "rotation or circulation" in thunderstorms during tornado warnings. The most destructive tornadoes are usually associated with supercell thunderstorms whose radar signature is a characteristic "hook" pattern, reflecting the counterclockwise rotation of the mesocyclone (below).
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 The schematic on the left shows the "hook" produced by the anticlockwise rotation of the mesocyclone. In the radar image on the right, you can see the "hook" in the supercell that formed the EF-4 tornado over Henryville.
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If you are in a scientific mood, you can read more about the development of mesocyclones on the National Oceanic and Atmospheric Administration (NOAA) web site. Visit this NOAA site for an explanation of the March 2 outbreak in Indiana and Kentucky and some aerial photographs showing the effects of the storm. Some of the worst damage in Kentucky occurred in West Liberty, a small town about 50 miles east of Lexington. An EF-3 tornado destroyed most of the downtown area.
This QuickTime movie is based on water vapor imagery from the Geostationary Operational Environmental Satellite (GOES) and shows the development of storms along this front several days before the Henryville tornado (If you are unable to link to the movie, go to http://goes.gsfc.nasa.gov/, GOES Scrapbooks and then QuickTime Movies. It's the only 2012 movie.) Note the upper atmosphere moisture (white) streaming in from the Gulf of Mexico along the jet stream. The moisture is being pulled northward by the large swirling low-pressure storm system over the Midwest (labeled "L" in the weather map above). This system spawned tornadoes primarily in Kansas, Missouri, Illinois and Kentucky on February 28 and 29.
This QuickTime movie is based on water vapor imagery from the Geostationary Operational Environmental Satellite (GOES) and shows the development of storms along this front several days before the Henryville tornado (If you are unable to link to the movie, go to http://goes.gsfc.nasa.gov/, GOES Scrapbooks and then QuickTime Movies. It's the only 2012 movie.) Note the upper atmosphere moisture (white) streaming in from the Gulf of Mexico along the jet stream. The moisture is being pulled northward by the large swirling low-pressure storm system over the Midwest (labeled "L" in the weather map above). This system spawned tornadoes primarily in Kansas, Missouri, Illinois and Kentucky on February 28 and 29.
A number of equine emergency personnel suggest that the safest place for a horse during a tornado is the pasture. Collapsed barns caused most of the equine fatalities in the March 2 storm. However, horses in open areas are also at risk from both the high winds and the flying debris. Don't forget that these are not straight-line winds, as observed in some thunderstorms. A tornado is a violently rotating column of air that can carry objects aloft for miles and scatter debris at high velocities in several different directions. In the case of the Henryville tornado, winds exceeded 175 miles/hr (282 km/hr).
Our mustangs instinctively head for the pastures during a storm. No one wants to stay inside! This is probably the case with many domestic horses, as well. Possible exceptions would be those horses that have been stabled for the majority of their lives and feel more secure in the barn. All our horses have 24/7 access to pastures.
We are fortunate that our pastures have some topographic relief -- rolling karst terrain with elevated areas separated by sinkholes with depths of ~ 10-20 feet. These low-lying areas provide the best protection for a horse during a storm. Many of the sinkholes are also lined with cedar trees, which will deflect some of the scattered debris (see image below). In less severe storms, we have seen some of our mustangs in these sinkholes positioning their bodies to minimize wind resistance and to protect their heads. These sinkholes do not hold water so "sinkhole flooding" is not a problem during storms.
Our mustangs instinctively head for the pastures during a storm. No one wants to stay inside! This is probably the case with many domestic horses, as well. Possible exceptions would be those horses that have been stabled for the majority of their lives and feel more secure in the barn. All our horses have 24/7 access to pastures.
We are fortunate that our pastures have some topographic relief -- rolling karst terrain with elevated areas separated by sinkholes with depths of ~ 10-20 feet. These low-lying areas provide the best protection for a horse during a storm. Many of the sinkholes are also lined with cedar trees, which will deflect some of the scattered debris (see image below). In less severe storms, we have seen some of our mustangs in these sinkholes positioning their bodies to minimize wind resistance and to protect their heads. These sinkholes do not hold water so "sinkhole flooding" is not a problem during storms.
Sinkhole formed from dissolution of underlying limestone rock and subsequent collapse of surface. The red cedars that line the banks of this sinkhole thrive in the calcium-rich soils of the Mitchell Plain. Their low, dense branches provide a good windbreak. The trunk of the deciduous tree in the foreground is ~ 4.5 feet in height.
All we can do is provide our horses with the opportunity to find these sheltered areas during a storm. It's no guarantee that they will survive an intense tornado but we believe that their chances are significantly improved if they have free access to pastures and are not confined to the barn. Horses and wild mustangs, in particular, have a way of taking care of themselves under extreme conditions.
Footnote: Our sincere condolences go out to those who suffered losses of family members, or animals, during the 2012 tornado outbreaks in the U.S.
Footnote: Our sincere condolences go out to those who suffered losses of family members, or animals, during the 2012 tornado outbreaks in the U.S.
Copyright George Lager, 2011-2015. All Rights Reserved (®)