Question: How many tornadoes does the state that this season's most successful American Idol contestant is from, have per year?

full_context: Document 1: Climate of North Carolina: Snow in North Carolina is seen on a regular basis in the mountains. North Carolina averages 5 inches (130 mm) of snow a year. However, this also varies greatly across the state. Along the coast, most areas register less than 2 inches (51 mm) per year while the state capital, Raleigh averages 7.5 inches (190 mm). Farther west in the Piedmont - Triad, the average grows to approximately 9 inches (230 mm). The Charlotte area averages approximately 6.5 inches (170 mm). The mountains in the west act as a barrier, preventing most snowstorms from entering the Piedmont. When snow does make it past the mountains, it is usually light and is seldom on the ground for more than two or three days. However, several storms have dropped 18 inches (460 mm) or more of snow within normally warm areas. The 1993 Storm of the Century that lasted from March 11 to March 15 affected locales from Canada to Central America, and brought a significant amount of snow to North Carolina. Newfound Gap received more than 36 inches (0.91 m) of snow with drifts more than 5 feet (1.5 m), while Mount Mitchell measured over 4 feet (1.2 m) of snow with drifts to 14 feet (4.3 m). Most of the northwestern part of the state received somewhere between 2 feet (0.61 m) an 3 feet (0.91 m) of snow.
Document 2: Climate of North Carolina: There is an average of forty - five inches of rain a year (fifty in the mountains). July storms account for much of this precipitation. As much as 15% of the rainfall during the warm season in the Carolinas can be attributed to tropical cyclones. Mountains usually see some snow in the fall and winter. Moist winds from the southwest drop an average of 80 inches (2,000 mm) of precipitation on the western side of the mountains, while the northeast - facing slopes average less than half that amount.
Document 3: American Idol: Both finalists found success after the show, but Aiken out-performed Studdard's coronation song "Flying Without Wings" with his single release from the show "This Is the Night", as well as in their subsequent album releases. The fourth-place finisher Josh Gracin also enjoyed some success as a country singer.
Document 4: American Idol: Chris Daughtry's performance of Fuel's "Hemorrhage (In My Hands)" on the show was widely praised and led to an invitation to join the band as Fuel's new lead singer, an invitation he declined. His performance of Live's version of "I Walk the Line" was well received by the judges but later criticized in some quarters for not crediting the arrangement to Live. He was eliminated at the top four in a shocking result.
Document 5: North Carolina: Severe weather occurs regularly in North Carolina. On the average, a hurricane hits the state once a decade. Destructive hurricanes that have struck the state include Hurricane Fran, Hurricane Floyd, and Hurricane Hazel, the strongest storm to make landfall in the state, as a Category 4 in 1954. Hurricane Isabel stands out as the most damaging of the 21st century. Tropical storms arrive every 3 or 4 years. In addition, many hurricanes and tropical storms graze the state. In some years, several hurricanes or tropical storms can directly strike the state or brush across the coastal areas. Only Florida and Louisiana are hit by hurricanes more often. Although many people believe that hurricanes menace only coastal areas, the rare hurricane which moves inland quickly enough can cause severe damage; for example, in 1989, Hurricane Hugo caused heavy damage in Charlotte and even as far inland as the Blue Ridge Mountains in the northwestern part of the state. On the average, North Carolina has 50 days of thunderstorm activity per year, with some storms becoming severe enough to produce hail, flash floods, and damaging winds.
Document 6: American Idol: Theories given for the success of Southerners on Idol have been: more versatility with musical genres, as the Southern U.S. is home to several music genre scenes; not having as many opportunities to break into the pop music business; text-voting due to the South having the highest percentage of cell-phone only households; and the strong heritage of music and singing, which is notable in the Bible Belt, where it is in church that many people get their start in public singing. Others also suggest that the Southern character of these contestants appeal to the South, as well as local pride. According to season five winner Taylor Hicks, who is from the state of Alabama, "People in the South have a lot of pride ... So, they're adamant about supporting the contestants who do well from their state or region."
Document 7: American Idol: Since the show's inception in 2002, ten of the fourteen Idol winners, including its first five, have come from the Southern United States. A large number of other notable finalists during the series' run have also hailed from the American South, including Clay Aiken, Kellie Pickler, and Chris Daughtry, who are all from North Carolina. In 2012, an analysis of the 131 contestants who have appeared in the finals of all seasons of the show up to that point found that 48% have some connection to the Southern United States.
Document 8: American Idol: As one of the most successful shows on U.S. television history, American Idol has a strong impact not just on television, but also in the wider world of entertainment. It helped create a number of highly successful recording artists, such as Kelly Clarkson, Daughtry and Carrie Underwood, as well as others of varying notability.
Document 9: American Idol: In what was to become a tradition, Clarkson performed the coronation song during the finale, and released the song immediately after the season ended. The single, "A Moment Like This", went on to break a 38-year-old record held by The Beatles for the biggest leap to number one on the Billboard Hot 100. Guarini did not release any song immediately after the show and remains the only runner-up not to do so. Both Clarkson and Guarini made a musical film, From Justin to Kelly, which was released in 2003 but was widely panned. Clarkson has since become the most successful Idol contestant internationally, with worldwide album sales of more than 23 million.
Document 10: North Carolina: North Carolina averages fewer than 20 tornadoes per year, many of them produced by hurricanes or tropical storms along the coastal plain. Tornadoes from thunderstorms are a risk, especially in the eastern part of the state. The western Piedmont is often protected by the mountains, which tend to break up storms as they try to cross over; the storms will often re-form farther east. Also a weather phenomenon known as "cold air damming" often occurs in the northwestern part of the state, which can also weaken storms but can also lead to major ice events in winter.
Document 11: American Idol: American Idol is an American singing competition television series created by Simon Fuller, produced by FremantleMedia North America and 19 Entertainment, and distributed by FremantleMedia North America. It began airing on Fox on June 11, 2002, and ended its first - run on April 7, 2016. On March 11, 2018, the show will make its debut on ABC. It started off as an addition to the Idols format based on the British series Pop Idol, and became one of the most successful shows in the history of American television. The concept of the series involves discovering recording stars from unsigned singing talents, with the winner determined by the viewers in America through telephones, Internet, and SMS text voting. Winners chosen by viewers in its fifteen seasons were Kelly Clarkson, Ruben Studdard, Fantasia, Carrie Underwood, Taylor Hicks, Jordin Sparks, David Cook, Kris Allen, Lee DeWyze, Scotty McCreery, Phillip Phillips, Candice Glover, Caleb Johnson, Nick Fradiani, and Trent Harmon.
Document 12: Tennessee: While the state is far enough from the coast to avoid any direct impact from a hurricane, the location of the state makes it likely to be impacted from the remnants of tropical cyclones which weaken over land and can cause significant rainfall, such as Tropical Storm Chris in 1982 and Hurricane Opal in 1995. The state averages around 50 days of thunderstorms per year, some of which can be severe with large hail and damaging winds. Tornadoes are possible throughout the state, with West and Middle Tennessee the most vulnerable. Occasionally, strong or violent tornadoes occur, such as the devastating April 2011 tornadoes that killed 20 people in North Georgia and Southeast Tennessee. On average, the state has 15 tornadoes per year. Tornadoes in Tennessee can be severe, and Tennessee leads the nation in the percentage of total tornadoes which have fatalities. Winter storms are an occasional problem, such as the infamous Blizzard of 1993, although ice storms are a more likely occurrence. Fog is a persistent problem in parts of the state, especially in East Tennessee.
Document 13: American Idol: Despite being eliminated earlier in the season, Chris Daughtry (as lead of the band Daughtry) became the most successful recording artist from this season. Other contestants, such as Hicks, McPhee, Bucky Covington, Mandisa, Kellie Pickler, and Elliott Yamin have had varying levels of success.
Document 14: American Idol: The show itself is popular in the Southern United States, with households in the Southeastern United States 10% more likely to watch American Idol during the eighth season in 2009, and those in the East Central region, such as Kentucky, were 16 percent more likely to tune into the series. Data from Nielsen SoundScan, a music-sales tracking service, showed that of the 47 million CDs sold by Idol contestants through January 2010, 85 percent were by contestants with ties to the American South.
Document 15: American Idol: Ruben Studdard emerged as the winner, beating Clay Aiken by a small margin. Out of a total of 24 million votes, Studdard finished just 134,000 votes ahead of Aiken. This slim margin of victory was controversial due to the large number of calls that failed to get through. In an interview prior to season five, executive producer Nigel Lythgoe indicated that Aiken had led the fan voting from the wildcard week onward until the finale.
ground_truth: fewer than 20
sub_queries: Who was the most successful artist from this season? Answer: Chris Daughtry
What state is American Idol contestant Chris Daughtry from? Answer: North Carolina
How many tornadoes does North Carolina have per year? Answer: fewer than 20