There was a continued trend of fewer natural hazard events overall in the United States for 2015, resulting in decreased damage and loss totals for the year, according to the annual Natural Hazard Risk Summary and Analysis, released by CoreLogic, a provider of consumer, financial and property information, analytics and services.
Despite the continued trend, there were still record-setting events that caused significant damage among individual hazard categories, CoreLogic said in a statement on Thursday.
For example, U.S. wildfire activity for 2015 was the worst in recorded history, with over 3.5 million more acres burned in 2015 than the yearly average of 6,579,250 from the previous 15 years (2000-2014), the report noted. The three most destructive wildfires of 2015 included: the Valley Fire in northern California, which burned 76,000 acres and destroyed 1,307 homes, with US$925 million in insured losses; the Butte Fire in northern California, which burned 70,000 acres and destroyed 475 homes, with US$225 million in insured losses; and the Okanogan Complex Fire in north central Washington, which burned 133,000 acres and destroyed 73 homes with US$8 million in insured losses.
Before 2004, the statement noted, a single wildfire had never burned more than eight million acres. Since then, seven of the last 12 years (2004, 2005, 2006, 2007, 2011, 2012 and 2015) have surpassed eight million acres burned.
In relation to floods in the U.S., at US$2.86 billion, total flood loss in 2015 was equivalent to that of 2014, but still well below the 30-year average of US$7.96 billion. Based on the snapshot statistics from the National Oceanic Atmospheric Administration Storm Event Database, property losses from flash flood events in the first nine months of 2015 were more than 15% higher than the losses from riverine floods.
For flash flood loss totals, Texas ranked first with property losses totaling more than US$309 million. This was followed by New York with almost US$14 million in property losses and Ohio with more than US$7 million.
For riverine flood loss totals, Nebraska ranks first with property losses totaling more than US$213 million. This was followed by Ohio with more than US$13 million in property losses and West Virginia with more than US$8 million.
In addition, the statement noted, South Carolina was hit with record-setting, 1,000-year rainfall fueled by Hurricane Joaquin, which led to riverine and flash flooding in 22 counties and caused US$1.5 billion worth of damage, including US$587 million in agricultural losses, US$181 million in insurance claims and US$35 million in tourism losses.
Hurricane activity in the Atlantic was below normal for 2015, with only 11 named storms, seven of which never grew stronger than a tropical storm. Of the four storms that were categorized as hurricanes, two were Category 1 and the other two grew into major hurricanes: Danny, a Category 3, and Joaquin, a Category 4. Even though no hurricanes made landfall in 2015 and no substantial wind or storm-surge damage occurred, storm-related precipitation from Tropical Storm Ana, Tropical Storm Bill and Hurricane Joaquin resulted in record-setting inland flooding.
For wind, severe wind activity was relatively low in 2015 with only 0.2% of the continental U.S. affected by wind speeds of 80 miles per hour (mph) or greater, CoreLogic reported. 2015 had the lowest number of annual recorded wind speeds of 65 mph or greater since 2006 when wind data collection began. A total of 31.5%, or 1,584,102 square miles, of the continental U.S. experienced wind events of 60 mph or greater in 2015.
Hail activity for 2015 was slightly above average with 369,691 square miles, or 7.4%, of the continental U.S. impacted by severe hail, defined as one inch or greater. On June 15, multiple storms produced large hail and heavy rainfall across the far southern and southwestern Chicago metro area. Giant hail was observed near Minooka, Ill., and the biggest hail reported measured 4.75 inches – the largest documented hail stone in Illinois since at least 1961. For hail sizes in which damage becomes prevalent – greater than 1.5 inches – 2015 recorded the eighth lowest hail fall in the last 10 years.
Tornado activity was slightly above average in 2015, the report said, with 1,252 recorded tornadoes. This total includes the 948 tornadoes that have been verified through September 2015, as well as an additional 238 tornadoes preliminarily logged from October to December. On April 9, 2015, an EF4 tornado travelled more than 30 miles through Rochelle and Fairdale, Ill., destroying scores of homes and killing two people and multiple injuries. With 76 confirmed tornadoes, Dallas/Fort Worth, Texas experienced the most tornado activity in 2015. This is the most on record for North and Central Texas since 1950 when the National Weather Service began tracking tornado activity.
Regarding earthquakes, 2015 was characterized by a slightly higher-than-average number of earthquakes (a total of 1,196 earthquakes of magnitude 3.0 or greater), however, none produced significant damage or losses, the statement said. Oklahoma experienced four times more earthquakes than both California and Oregon, two states that traditionally have the greatest seismic hazard activity in the U.S. Although earthquakes in Oklahoma occur more frequently, the majority are of smaller magnitude (M<4.0) than those in California. There has been an increase in the number of earthquakes in the central U.S. caused by induced seismicity which is defined as not related to naturally occurring (tectonic) activity, the report said, adding that induced earthquakes in the U.S. can occur as a result of hydraulic fracturing or wastewater injection associated with natural gas exploration. “This could explain why earthquake activity in Oklahoma, Kansas and northern Texas has increased in recent years,” the statement suggested.
Sinkhole activity was low in 2015, with 2,206 new sinkhole events recorded across the U.S. At the state level, Florida recorded the highest number of sinkhole events in 2015, with 2,206 new sinkholes added in 2015 for the top 10 counties in that state. (The total number of sinkholes in the CoreLogic database for Florida is 28,159). The low-level sinkhole activity for the year could be related to the absence of land-fall hurricanes, which bring significant rain that increases erosion of the subsurface layers and increases sinkhole probability, the statement concluded.