Straight Line Winds, Hail, Straight Line Winds, Hail, & Crop Damage& Crop Damage

Nathan Schnur Nathan Schnur 02/15/200802/15/2008

Yearly Damage Statistics for IowaYearly Damage Statistics for Iowa

• 20072007• Hail - $2,768,390.12Hail - $2,768,390.12• Wind - 6, 163, 356.44Wind - 6, 163, 356.44

• 20062006• Hail - $1,082,100.54Hail - $1,082,100.54• Wind - $1,483,016.11Wind - $1,483,016.11

• 20052005• Hail - $897,598.88Hail - $897,598.88• Wind - $143, 879.78Wind - $143, 879.78

Data taken from the USDA Risk Management Agency @ http://www.rma.usda.gov/

Criteria for Severe WeatherCriteria for Severe Weather

• National Weather Service CriteriaNational Weather Service Criteria• HailHail

• Dime size or largerDime size or larger

• WindWind• 58mph or greater58mph or greater

• Comes in many shapes & sizesComes in many shapes & sizes• Pea Pea Softball Softball• Rarely larger than softballRarely larger than softball

• Can cause substantial damage to Can cause substantial damage to cropscrops

• Largest hail usually generated in Largest hail usually generated in supercell thunderstormssupercell thunderstorms

HailHail

Right: Record setting hailstone which was 6.5 inches long and 17.3 inches around. It fell June 23, 2003 near Hastings, NE.

Hail DamageHail Damage

• Often looks worse than it really isOften looks worse than it really is

• Plants can usually grow backPlants can usually grow back

• Highest potential for severe Highest potential for severe damage is during floweringdamage is during flowering

• Secondary ProblemsSecondary Problems• Fungal InfectionsFungal Infections

• Caused by Bow Echo’s, Squall Lines, or Derecho’sCaused by Bow Echo’s, Squall Lines, or Derecho’s

• Winds which cause most damage are >58mphWinds which cause most damage are >58mph• Derecho winds can be >100mph Derecho winds can be >100mph

• Damage to crops can be extensiveDamage to crops can be extensive

• Macro and Microbursts also cause damageMacro and Microbursts also cause damage• Winds often >70mphWinds often >70mph

Straight Line WindsStraight Line Winds

Straight Line Wind DamageStraight Line Wind Damage

• Damage looks worse than it is in most casesDamage looks worse than it is in most cases

• Yield losses vary depending on time of damageYield losses vary depending on time of damage

• Can lead to secondary problemsCan lead to secondary problems• Goose-neckingGoose-necking• Increased risk for fungal infectionIncreased risk for fungal infection• Decreased nutrient and water uptakeDecreased nutrient and water uptake• Causes harvest problemsCauses harvest problems

Day after storm July 10th Same field July 16th

ReferencesReferences

Photos Courtesy of:Photos Courtesy of:• http://www.flickr.com/photos/wayneklick/133958153/http://www.flickr.com/photos/wayneklick/133958153/• http://www.uvm.edu/~sbraaten/MarbleheadMAhailstones.jpghttp://www.uvm.edu/~sbraaten/MarbleheadMAhailstones.jpg• www.hprcc.unl.eduwww.hprcc.unl.edu• http://www.agry.purdue.edu/ext/corn/news/articles.00/HailDamage-0522-http://www.agry.purdue.edu/ext/corn/news/articles.00/HailDamage-0522-

Gallery.htmlGallery.html• http://cropwatch.unl.edu/archives/2001/crop01-14.htmhttp://cropwatch.unl.edu/archives/2001/crop01-14.htm• http://www.flickr.com/photos/carquestguy/1207484104/http://www.flickr.com/photos/carquestguy/1207484104/• http://www.extension.iastate.edu/nwcrops/storm-damage-02.htmhttp://www.extension.iastate.edu/nwcrops/storm-damage-02.htm

References:References:• http://www.weather.gov/http://www.weather.gov/• http://www.spc.noaa.gov/http://www.spc.noaa.gov/