Hail-Purple

__**HAIL**__  Steven S. & Charlie B.   Purple Class

 //Introduction // Hail is a type of precipitation, that forms when water droplets freeze together in the cold upper region of a thunderstorm clouds (cumulonimbus clouds). Hail is between 5mm. to 15cm. in diameter, and can be round or jagged. Hail stones aren't frozen rain drops, but they actually fall frozen from the start.(1&2)

=//**Dangers** //=  Hail storms can damage buildings, vehicles, crops, and also injure people. These projectiles are known as hail stones and can vary between 5mm. and 15cm. in diameter. Hail storms are specifically dangerous because hail is a solid projectiles that fall at high speeds as they grow in size. The combination of gravity and downwards wind can propel a hailstone at speeds of 90 mph. This means that the hail storms can cause unbelievable damage on the surface of the object they hit. (1&2) In a year hail storms cause an average of $ 1.6 billion in damage in residential roofs in the United States. It is also known to be the most destructive part of a thunder storm.(3)

//Conditions of Formation //
Hail starts its formation with small waters drops that are lifted into the atmosphere to a point at which they are super cooled. Super cooling occurs when the temperature is below freezing in the cumulonimbus clouds. Cumulus clouds typically form when warm air rises and reaches a level of cool air, where the moisture in the air condenses, this makes the water drops These small ice balls begin to fall, but are suspended in a warm updraft. This updraft brings the ice balls into the cooler part of the cloud were more ice layers are added. The cycle can be repeated many time adding on several layers of ice that.(6) Hail can between 5mm. to 15cm. The longer the hailstone is in the cycle the larger and larger the hailstone can grown.(1)

//Historical Examples //
Hail storms can be very deadly, a particularly deadly one was in. It recorded over 250 deaths just from this one hail storm that occurred.(1) Hail stones can also be very large as shown by on that fell near Aurora, Nebraska in June 23, 2003 it set the world record for being 7.0 inches in diameter and 18.75 inches in circumference.(2) Huge hail storm happened last year in central Oklahoma on May 16, 2010. A warm front moved in and a strong up draft was created, golf ball sized hail was mostly reported but some baseball size hail was also. Wind speeds averaged about 50 MPH. and damages cost over a million dollars.

Interested in learning about the deadliest and record breaking hail storms, check out this website for more information on this : http://atlasobscura.com/blog/hail-no-an-account-of-the-worlds-biggest-deadliest-hailstorms

//Safety // In the 18th century to prevent hail the europeans try shooting cannons into clouds, now the government has tried a method called cloud seeding, neither of these has been proven to work, so in the meantime here are some other ways to stay safe.(1) If hail begins to fall it is important to get inside, and to stay away from windows that can be easily broken by the hail. Hard top vehicles are okay unless the hail has reached golf ball size or larger.(3)

Interested in hail, for more information watch this video : http://www.youtube.com/watch?v=ed5jm7aSL7Y&feature=relate

//Sources // 1. National Goegrapic. “Hail.” //National Geograpic//. National Geographic, n.d. Web. 17 Jan. 2012. . 2. Agency Hail Suppression. " Hail Formation." Agency Hail Suppression, Web. 17 Jan. 2012  3. NOAA. “Hail Safety.” //NOAA//. NOAA, 4 Feb. 2010. Web. 17 Jan. 2012. <www.crh.noaa.gov/‌riw/‌severe/‌hail.php>. 4. Federal Alliance For Safe Homes. "Hail Overview." FLASH, Web 17 Jan 2012. <Flash.org/peril_hail.php> 5. NOAA. “The May 16, 2010 Hail Storm in Central Oklahoma.” //NOAA//. NOAA, 15 Sept. 2010. Web. 17 Jan. 2012. <www.srh.noaa.gov/‌oun/‌?n=events-20100516>. 6. <span style="background-color: #ffffff; color: #333333; font-family: Arial,Verdana,Helvetica,sans-serif,'Arial Unicode MS';">Harold D. Orville, "Hail," in AccessScience, ©McGraw-Hill Companies, 2008, Web. 17 Jan 2012 < accessscience.com/content/Hail/304900#s2>