{"41229":{"#nid":"41229","#data":{"type":"news","title":"Tornado Threat Increases as Gulf Hurricanes Get Larger","body":[{"value":"\u003Cp\u003ETornadoes that occur from hurricanes moving inland from the Gulf Coast are increasing in frequency, according to researchers at the Georgia Institute of Technology. This increase seems to reflect the increase in size and frequency among large hurricanes that make landfall from the Gulf of Mexico. The findings can be found in Geophysical Research Letters online and in print in the September 3, 2009 issue.\u003C\/p\u003E\u003Cp\u003E\u0022As the size of landfalling hurricanes from the Gulf of Mexico increases, we\u0027re seeing more tornadoes than we did in the past that can occur up to two days and several hundred miles inland from the landfall location,\u0022 said James Belanger, doctoral student in the School of Earth and Atmospheric Sciences at Georgia Tech and lead author of the paper.\u003C\/p\u003E\u003Cp\u003ECurrently, it\u0027s well known that when hurricanes hit land, there\u0027s a risk that tornadoes may form in the area. Until now, no one has quantified that risk because observations of tornadoes were too sporadic prior to the installation of the NEXRAD Doppler Radar Network in 1995. Belanger along with co-authors Judith Curry, professor and chair of the School of Earth and Atmospheric Sciences at Tech and research scientist Carlos Hoyos, decided to see if they could create a model using the more reliable tornado record that\u0027s existed since 1995.\u003C\/p\u003E\u003Cp\u003EThe model that they developed for hurricane-induced tornadoes uses four factors that serve as good predictors of tornado activity: size, intensity, track direction and whether there\u0027s a strong gradient of moisture at midlevels in the storm\u0027s\u003Cbr \/\u003E environment.\u003C\/p\u003E\u003Cp\u003E\u0022The size of a tropical cyclone basically sets the domain over which tornadoes can form. So a larger storm that has more exposure over land has a higher propensity for producing tornadoes than a smaller one, on average,\u0022 said Belanger.\u003C\/p\u003E\u003Cp\u003EThe team looked at 127 tropical cyclones from 1948 up to the 2008 hurricane season and went further back to 1920 modifying their model to account for the type of data collected at that time. They found that since 1995 there has been a 35 percent percent increase in the size of tropical cyclones from the Gulf compared to the previous active period of storms from 1948-1964, which has lead to a doubling in the number of tornadoes produced per storm. The number of hurricane-induced tornadoes during the 2004 and 2005 hurricane seasons is unprecedented in the historical record since 1920, according to the model.\u003C\/p\u003E\u003Cp\u003E\u0022The beauty of the model is that not only can we use it to reconstruct the observational record, but we can also use it as a forecasting tool,\u0022 said Belanger.\u003C\/p\u003E\u003Cp\u003ETo test how well it predicted the number of tornadoes associated with a given hurricane, they input the intensity of the storm at landfall, it\u0027s size, track and moisture at mid-levels, and were able to generate a forecast of how many tornadoes formed from the hurricane. They found that for Hurricane Ike in 2008, their model predicted exactly the number of tornadoes that occurred, 33. For Hurricane Katrina in 2005, the model predicted 56 tornadoes, and 58 were observed.\u003C\/p\u003E\u003Cp\u003EThe team\u0027s next steps are to take a look to see how hurricane size, not just intensity (as indicated by the Safir-Simpson scale), affects the damage experienced by residents.\u003C\/p\u003E\u003Cp\u003E\u0022Storm surge, rain and flooding are all connected to the size of the storm,\u0022 said Curry. \u0022Yet, size is an underappreciated factor associated with damage from hurricanes. So its important to develop a better understanding of what controls hurricane size and how size influences hurricane damage. The great damage in Galveston from Hurricane Ike in 2008 was inconsistent with Category 2 wind speeds at landfall, but it was the large size that caused the big storm surge that did most of the damage.\u0022\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003ETornadoes that occur from hurricanes moving inland from the Gulf Coast are increasing in frequency, according to researchers at the Georgia Institute of Technology. This increase seems to reflect the increase in size and frequency among large hurricanes that make landfall from the Gulf of Mexico.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Increase reflects growth in size and frequency of Gulf hurricane"}],"uid":"27310","created_gmt":"2009-08-17 00:00:00","changed_gmt":"2016-10-08 03:02:15","author":"David Terraso","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2009-09-08T00:00:00-04:00","iso_date":"2009-09-08T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"41230":{"id":"41230","type":"image","title":"Hurricane Ike","body":null,"created":"1449174285","gmt_created":"2015-12-03 20:24:45","changed":"1475894366","gmt_changed":"2016-10-08 02:39:26","alt":"Hurricane Ike","file":{"fid":"190031","name":"tpr25667.jpg","image_path":"\/sites\/default\/files\/images\/tpr25667.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/tpr25667.jpg","mime":"image\/jpeg","size":279975,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tpr25667.jpg?itok=30sJy76z"}}},"media_ids":["41230"],"related_links":[{"url":"http:\/\/www.eas.gatech.edu\/","title":"School of Earth and Atmospheric Sciences"},{"url":"http:\/\/curry.eas.gatech.edu\/","title":"Judy Curry"}],"groups":[{"id":"1183","name":"Home"}],"categories":[{"id":"154","name":"Environment"},{"id":"135","name":"Research"}],"keywords":[{"id":"1863","name":"belanger"},{"id":"85","name":"curry"},{"id":"1862","name":"gulf"},{"id":"1864","name":"hoyos"},{"id":"1860","name":"hurricane"},{"id":"1861","name":"tornadoes"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EGeorgia Tech Media Relations\u003C\/strong\u003E\u003Cbr \/\u003ELaura Diamond\u003Cbr \/\u003E\u003Ca href=\u0022mailto:laura.diamond@comm.gatech.edu\u0022\u003Elaura.diamond@comm.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-894-6016\u003Cbr \/\u003EJason Maderer\u003Cbr \/\u003E\u003Ca href=\u0022mailto:maderer@gatech.edu\u0022\u003Emaderer@gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-660-2926\u003C\/p\u003E","format":"limited_html"}],"email":["david.terraso@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}