Freezing+Rain-Green

**Freezing Rain** Lina S. & Melanie C. Green Class

[[image:MCLS_Freezing_Rain_split_tree.jpg width="284" height="223" align="left" caption="Figure 1: Tree split due to the weight of the ice on its branches"]]
Introduction Freezing rain develops when snow high in the atmosphere hits a layer of warm air, turning the snow into rain (2). Before the rain hits the surface, however, there is a layer of air with a temperature below 0°C (1). The cold layer of air causes the rain drops to be supercooled, they do not freeze, and keep falling as rain with a temperature below freezing (2). The rain drops then freeze on contact forming clear layers of ice on roads, trees, and telephone poles (2). Its damage on nature has the ability to produce results similar to those of severe tornadoes (2). Despite the damage caused, freezing rain is one of the most difficult weather types to forecast because it affects narrow bands of area that are only fifty kilometers wide (2).

Dangers: to humans and nature  Freezing rain is most often the cause of car accidents and power outages (2). It is invisible on smooth surfaces which results in slipping on sidewalks and on roads, thus, further adding to its dangers (2). In only hours, freezing rain can immobilize a region completely (2). Humans are affected mainly because of the changes in environment: telephone poles freeze over, trees break due to the weight of ice on its branches, and ice coats the ground with a clear glaze. Freezing rain is especially bad for telephone poles because the ice that coats the telephone wires will damage the telephone poles having the ability to weigh up to four tons, as seen in Figure 2 (2). Freezing rain not only affects humans, but it also affects nature all the more. As seen in Figure 1, the ice on a tree's branches can weigh down the tree so much that as a result, the tree dies (2). Ice can also build up in an animal's nostrils causing suffocation (2). For example, birds can be grounded through frozen wings, the weight of ice on their wings, or simply being frozen to trees (2). Birds can also suffocate through the freezing of their beaks and build up of ice in their nostrils (2). For humans, the damage may not be caused but the ice directly, but by the results afterwards. Over 500 people a year die because of carbon monoxide poisoning (8). The carbon monoxide occurs when people inside a house use a back-up heater or things such as a barbeque or gas stove (8). When these things are used inside and not properly ventilated, they may cause both carbon monoxide and fires to occur (8).

  Conditions of Formation Freezing rain occurs when the temperature is at or just below freezing ( 0 °C or 32° F). There are two processes in which freezing rain forms: the ice crystal process and the supercooled warm-rain process (2). The ice crystal process is the most common process where freezing rain actually starts as snow high in the atmosphere where they grow bigger through the collecting of water vapor (2). The snow falls from a cloud, which has a temperature of below -10 ° C, but passes through a layer of warm air (above 0 °C) causing the ice crystals melt (2 & 8). These rain drops then fall through a very thin layer of cold air just above the surface (below 0 °C) causing the drops to be supercooled (2). They do not freeze in the cold layer of air because of the few ice nuclei in the layer of air (2). The drops then freeze on contact turning to ice. The supercooled warm-rain process is less common and occurs when the temperature of the cloud is warmer than -10  °  C (2). Instead of the formation of ice crystals, microscopic cloud droplets collect vapor as they fall and do not freeze since there are few ice nuclei in warm temperatures (2). Freezing rain is most commonly associated with mid-latitude cyclones where the air going over a warm front cools and condenses producing a narrow band of extremely heavy freezing rain. Freezing rain also occurs behind the cold front associated with mid-latitude cyclones due to southerly winds pushing warm air over the front, however it is much lighter and very brief (2). Freezing rain can also be produced from stationary fronts when warm southerly air is pushed over cold northern air (2). The front acts like a barrier between the warm south air and the cold north air and, as a result, freezing rain is produced on the northern side. Another way freezing rain is produced is by cold-air damming (2). Cold-air damming is the result of cold, high pressure air rushing southward towards warm, low pressure air from the ocean (2). When the two air masses meet, the warm moist air rises over the cold air producing precipitation that falls through a warm layer of air, then a cold layer of air (2). Thus, freezing rain is a common result of cold-air damming. Another phenomenon that can result in freezing rain is a large area of low pressure called an "extended low" (2). This is often the result of a dying cyclone where upper-level winds bring warm air over the cold air associated with the low pressure zone. Freezing rain can occur anywhere in the extended low, given that the temperatures are correct. Lastly, freezing rain can also be associated with anticyclones where high southerly winds push warm air up and over cold air associated with the high pressure center (2).

<span style="font-family: 'Comic Sans MS',cursive; font-size: 24px; line-height: 22px;">Historical Examples <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 15px; line-height: 22px;"> <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 15px; line-height: 22px;">Freezing rain is encountered all over the world. Some examples date far back in history, for instance in 1921, New England experienced an ice storm that obliterated seven-thousand and five-hundred to eight-thousand trees and damaged five-thousand to seven-thousand trees to the extent that the were going to die anyways (2). On a telephone wire it was measured that the weight of the ice between the two telephone poles weighed more than four tons (2). Another storm, the Eastern Ontario freezing rain storm of 1942, started on December 28th and ended on December 30th, lasting two days (3). It was described as having ice "as thick as a person's wrist", it covered train tracks,, wires and cars (3). On January 4th, 1998, the most destructive and horrific storm in Northern America occurred earning the title "Ice Storm of the Century" (3). The storm lasted six days, ending on the 9th, totaling a cost of two to three billion dollars in damage (3 & 5). The storm in Canada took thirty-five lives and brought down millions of trees, thirty-thousand utility poles, one-hundred and thirty transmission towers, one-hundred and twenty-thousand km of telephone and power lines, and an electric system that took years to build, but was brought down in a matter of days (3 & 5). <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 110%;"> The casualties were causes mainly from hypothermia and carbon monoxide poisoning (5). In addition, it rained more than eighty hours consecutively, the total precipitation being twice the amount of Canada's yearly precipitation (3& 5). The storm also caused power outages in Quebec in over nine-hundred thousand houses and over one-hundred thousand houses in Ontario (5). The power outages lasted from only a couple hours to up to four weeks (5). The same storm had lasting affects on New York and northern New England as well (6). One of the reasons this storm was so powerful was because it was a year where the El Nino pattern was moderate to strong; this influenced the jet stream (6). The influence from El Nino was that downstream, the Southern Pacific jet brings more moisture to the Pacific Coast and the southern section (6). <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 110%;">Also, both the Arctic and Polar jet streams usually stay over Canada (6). This moderates the temperature in both Canada and the United States (6).



<span style="font-family: 'Comic Sans MS',cursive; font-size: 24px; line-height: 22px;">Safety

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 15px; line-height: 22px;">When a freezing rain advisory has been televised, there a few pointers that would keep people safer. For the first and overall safety pointer that applies to all severe weathers, STAY INDOORS (4). Staying indoors and avoiding driving prevents catching

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 15px; line-height: 22px;"> sickness, slipping on ice and many other misfortunes. However, if staying outdoors or leaving the house is an absolute necessity, there are a few items a traveler should bring during a freezing rain storm. First and foremost is a survival kit containing a first-aid supplies, flashlights, extra batteries, a battery-powered radio, water, canned or dried foods, a manual can opener, a fire distinguisher, and a battery-operated cell phone charger (4 & 7). A car kit is also necessary, containing the survival kit and flares, blankets, warm clothes, sand or kitty litter, a small can, waterproof matches for melting snow, a shovel, a windshield scraper, and a knife (4 &7). It is essential for drivers to go slowly, especially on bridges because they tend to get coated with ice faster than other places, and to keep a distance from other drivers to prevent collisions. If stranding occurs, it is important to stay in the car with your windows open just a crack; having the windows open prevents carbon monoxide poisoning, a result that causes the deaths of five-hundred people a year in the United States (7 & 8). If stranding occurs while walking outside, be aware of trees (because ice can cause branches to fall), utility poles, and power lines. Also be sure to be cautious around cars since ice can cause slipping and prevent cars from stopping at an intersection (7). For more information, watch the video below of "[|How to Stay Safe in an Ice Storm]".

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">**For Further Entertainment...**
 * <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Watch a drive through the [|Dublin Ice Storm of December 2008] . Notice the branches scattered across the road and the branches that slap the windshield - they are covered with a layer of ice!
 * <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Watch a video of [|Moscow glazed in a layer of ice]... poor Santa!
 * <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">To check out a recent article from Boston News, check out [|Freezing Rain Causes Several Crashes]

<span style="font-family: 'Comic Sans MS',cursive; font-size: 24px; line-height: 22px;">Sources
 * 1) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Students of the University of Illinois. "Ice Crystal Mechanisms." //The Weather World 2010//. Illinois, 2010. Web. <http://ww2010.atmos.uiu.edu/(Gh)/guides/mtr/cld/prcp/zr/prcs/ice.rxml> 9 January 2012
 * 2) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Students of the University of Illinois. "Freezing Rain." //The Weather World 2010//. Illinois, 2010. Web. <http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/prcp/zr/frz.rxml ><span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">. 9 January 2012.
 * 3) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Scientists of Canadian government. "Historical Ice-Sorm Related Events." //Government of Canada.//Canada, 2011. Web. <http://ontario.hazards.ca/historical/Ice_Ontario-e.html>. 11 January 2012.
 * 4) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">WKYT News Team. "Winter Weather Safety Tips." //WKYT 29 Newsfirst.// Kentucky, 29 November 2010. Web. <http://www.wkyt.com/weather/misc/winter_weather_safety_tips_110974434.html>. 11 January 2012.
 * 5) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;"><span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Library and Archives of Canada. "Ice Storm 1998." //SOS! Canadian Disasters.//Canada, 14 February 2006. Web. < http://collectionscanada.gc.ca/sos/002028-5100-e.html>. 12 January 2012.
 * 6) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">NOAA. "10th Anniversary of the Devastating 1998 Ice Storm in the Northeast." //NOAA's National Weather Service.// Burlington, Vermont, 5 January 2008. Web. <http://www.erh.noaa.gov/btv/events/IceStorm1998/ice98.shtml>. 17 January 2012.
 * 7) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Jordana Giorgio, Rosemarie Lennon, Taige Jensen, and Johnathan Roberts. "How to Stay Safe in an Ice Storm." //Howcast.// San Francisco/New York, 25 March 2009. Video. <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">< http://www.howcast.com/videos/125530-How-To-Stay-Safe-in-an-Ice-Storm>. 16 January 2012.
 * 8) <span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Natural Dangers Association. "Cold & Ice Storms." //Natural Dangers Association.// Web. < http://www.n-d-a.org/cold-ice-storm.php<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">>. 17 January 2012.