Sleet-Purple

Sleet Katie G & Graham N Purple Class

Introduction Sleet is rain or melted snow that freezes as is falls to Earth. (1) Sleet normally forms during the winter months taking the shape of small ice pellets. While sleet isnot extremely dangerous is can cause some health risks.

Dangers Sleet causes slippery roads and sidewalks causing a skidding and falling hazard, and is easily mistaken for rain. When sleet accumulates on electrical wires they can break and become a serious safety hazard to cars, pedestrians, and homes. Sleet can accumulate on steps and railings causing people to slip and injure themselves while leaving or entering their home. Although sleet is not a particularly dangerous form of severe weather, it can be uncomfortable.

Conditions of Formation Sleet occurs when there is a layer of air at earths surface that is below freezing, and the layer of air above it is above freezing temperatures. (4) The conditions of sleet occur most often during the winter when warm air is forced over cool air, and it usually happens during a warm front. As air is forced upwards the air expands and cools adiabatically. (2) When air reaches the dew point water begins to condense on particle nueclei forming clouds. The dew point is the temperature at which water vapor condenses out of the air. This happens because warm air has a higher capacity than cold air, so when air is cooled the capacity decreases and when the air is cooled enough it becomes saturated and the air can not hold more water and some water vapor is forced out. When the water condenses it either forms rain or freezes and forms snow. This snow or rain falls through the layer of warm air, melts, and then falls through the air that is below freezing and freezes forming sleet. (4)

Historical Examples

On January ninth 2011, the mid-southern region of the United States including Texas, Arkansas, Georgia, and the Carolinas. These states experienced a serious sleet storm which caused travel delays, as well as power outages. Many people were affected by this sleet storm, because of the storms large area, quick movement, and long lifespan. This type of storm was unexpected because sleet storms are uncommon in the southern USA, and the national guard stepped in to help control, and restore damages caused by the storm. (2)



Safety Stay off of the roads, if driving is essential drive slowly and do not suddenly break for the car will skid. (3) Walk carefully outside because sleet accumulates quickly and is slippery. (1) Watch out for downed power lines because they can be a serious health risk. (1) Be careful while walking up and down stairs because sleet is slippery and may cause falling. Sources 1.University of Illinois. //All about Sleet.// All about Sleet: It's Slippery. University of Illinois. Jan 2010. Web. Jan 09 2012 http://ww2010.atmos.uiuc.edu/(Gl)/guides/mtr/cld/prcp/zr/sleet.rxml 2."Sleet." //education.nationalgeographic.com//. National Geographic, n.d. Web. 9 Jan. 2012. . 3."Winter Weather Preparedness Week." //erh.noaa.gov//. National Weather Service, n.d. Web. 11 Jan. 2012. Winter_Preparedness_SATURDAY.pdf>. 4.WeatherStreet. //What Causes ice pellets.// WeatherStreet.com. Sleet. Web. Jan 2010. http://www.weatherquestions.com/What_causes_ice_pellets.htm 5."Winter Weather Preparedness Week." //erh.noaa.gov//. National Weather Service, n.d. Web. 11 Jan. 2012. Winter_Preparedness_SATURDAY.pdf>. 6. Gargis, Peggy. "Snow, Sleet Storms Create Headaches in South." //mnn.com//. Mother Nature Network, n.d. Web. 15 Jan. 2012. . =Links= [] Sleet Storm [] Diagrams of Sleet Formation