HAILSTONES

 

Hailstones are scarce, ephemeral, polycrystalline, concentrically layered, monomineralic rocks of meteoric origin.  They are composed of the mineral ice (hydrogen oxide, H2O).  Ice has a low melting temperature for a mineral (= 0Ż Celsius/Centrigrade; = 32Ż Fahrenheit; = 273Ż Kelvin).  As a result of this, rocks (hailstones, firn, glacial ice) and sedimentary deposits (snow) consisting of ice are ephemeral, except at very high elevations (mountain tops) and in polar to near-polar facies.  Hailstones form in many thunderstorms and can reach the land surface before melting.  They range in size from about half-a-centimeter to >20 cm (very large hailstones, including the largest on record, shown here, are not really hailstones, but are aggregate hailstones, formed by ice cementing many smaller hailstones together).  Hailstones form spherical to subspherical to irregularly-shaped masses.

 


 

Hailstones - small hailstones (<1 cm) caught on branches of a spruce tree at Oberlin Bend-Garden Wall viewpoint, just northwest of Logan Pass, Glacier National Park, northwestern Montana, USA (3 September 2008).

 

Storm clouds over the Livingston Range from the storm system that spawned the hailstones shown above, Oberlin Bend-Garden Wall viewpoint, just northwest of Logan Pass, Glacier National Park, northwestern Montana, USA (3 September 2008).

 



 

Hailstones (<1 cm each) along Cripple Creek-Florissant Road, Teller County, central Colorado, USA (28 July 2009).  The translucency of many of these hailstones allows observation of internal concentric layering.

 

Hailstones (<1 cm each) from along Cripple Creek-Florissant Road, Teller County, central Colorado, USA (28 July 2009).

 

Hailstone - translucent hailstone showing internal, irregularly-concentric layering.  Same locality & date as the two photos above.

 

Hailstones partially covering landscape along Cripple Creek-Florissant Road, Teller County, central Colorado, USA (28 July 2009).

 

Storm clouds from the system that spawned the hailstones shown above, Cripple Creek-Florissant Road, Teller County, central Colorado, USA (28 July 2009).

 



 

Hailstone - irregularly-shaped, concentrically-layered hailstone (~2.5 cm across) in front of Founders Hall, Ohio State University at Newark campus, Newark, Ohio, USA (4 June 2010).

 

Hailstone - irregularly-shaped hailstone (>2 cm across) from in front of Founders Hall, Ohio State University at Newark campus, Newark, Ohio, USA (4 June 2010).

 

Storm clouds from the system that spawned the hailstones shown above (4 June 2010).  View from Ohio State University at Newark campus, Newark, Ohio, USA.

 



 

The most significant hailstone occurrence & hailstone damage I've ever seen was at Limon, Colorado, USA on the evening of 4 July 2010 and the following morning.

 

Storm clouds over Limon, Colorado, USA on 4 July 2010.  A relatively small, but intense, storm cell went over the small town of Limon on America's Indepedence Day, resulting in the deposition of a moderately thick layer of small-to-large hailstones in surface depressions.

Video of the hailstorm taken by Tony Laubach.

 

Hailstone deposit at a motel in Limon, Colorado, USA on 4 July 2010.

 

Hailstones at a motel in Limon, Colorado on 4 July 2010.  These rocks range from nearly spherical to subspherical to slightly irregularly-shaped.  The largest specimens range from ~1.5 to ~2.5 cm in diameter.

 

Hailstones deposited by a 4 July 2010 storm in Limon, Colorado, USA.  Hailstone size changed over time, resulting in the ~bimodal size distribution shown here.  The small hailstones are principally composed of cloudy ice (the cloudiness is produced by a high number of inclusions in the ice - small bubbles of air).  Many of the larger hailstones (~1.5 to 2.5 cm in diameter) have noticeable concentricity, consisting of zones of cloudy ice + clear, inclusion-free ice.

 

Hailstones generated by a 4 July 2010 storm at Limon, Colorado, USA.  The largest specimens have a ~2.5 cm diameter.  They range from being nearly spherical to subtriangular to irregular in shape

 

Hailstones - large, irregularly-shaped specimens from a 4 July 2010 storm at Limon, Colorado, USA.  The largest ones are just over 3 cm in diameter.

 

Hailstone damage - broken window on 2nd floor of west-facing side of a motel in Limon, Colorado, USA (morning following the 4 July 2010 hailstorm).

 

Hailstone damage - broken front windshield of car parked at a motel in Limon, Colorado, USA (morning following the 4 July 2010 hailstorm).

 

Hailstone damage - shattered back windshield of a car that was being driven during the 4 July 2010 hailstorm at Limon, Colorado, USA.

 

Hailstone damage on various vehicles in Limon, Colorado, USA from the 4 July 2010 hailstorm.

 



 

Hailstones falling during an 11 August 2010 storm over Elk Park Pass, northeast of Butte, Montana, USA.  The largest hailstones here had a diameter of >2 cm (see below).

 

Hailstones consisting of cloudy ice, generated by a late afternoon storm on 11 August 2010 at Elk Park Pass, northeast of Butte, Montana, USA.  The coin is ~2.1 cm in diameter.

 



 

Hailstones & hailstone splashes during a 16 June 2011 storm in Newark, Ohio, USA.  The hailstones are described as “pea-sized”.  Photo by Mary Ellen St. John.

 


 

 

Home page