Question: How many tornadoes occur per year in the state where its Civil War governor died?

<P0-S0> fog is fairly common, particularly in spring and early summer, and the occasional tropical storm or hurricane can threaten the region, especially in late summer and early autumn. <P0-S1> due to its situation along the north atlantic, the city often receives sea breezes, especially in the late spring, when water temperatures are still quite cold and temperatures at the coast can be more than 20 °f (11 °c) colder than a few miles inland, sometimes dropping by that amount near midday. <P0-S2> thunderstorms occur from may to september, that are occasionally severe with large hail, damaging winds and heavy downpours. <P0-S3> although downtown boston has never been struck by a violent tornado, the city itself has experienced many tornado warnings. <P0-S4> damaging storms are more common to areas north, west, and northwest of the city. <P0-S5> boston has a relatively sunny climate for a coastal city at its latitude, averaging over 2,600 hours of sunshine per annum. <SEP> <P1-S0> Senator. <P1-S1> Zebulon Baird Vance (May 13, 1830 – April 14, 1894) was a Confederate military officer in the American Civil War, the 37th and 43rd Governor of North Carolina, and U.S. <P1-S2> A prolific writer, Vance became one of the most influential Southern leaders of the Civil War and postbellum periods. <P1-S3> As a leader of the "New South", Vance favored the rapid modernization of the southern economy, railroad expansion, school construction, and reconciliation with the North. <SEP> <P2-S0> 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. <P2-S1> tornadoes are possible throughout the state, with west and middle tennessee the most vulnerable. <P2-S2> occasionally, strong or violent tornadoes occur, such as the devastating april 2011 tornadoes that killed 20 people in north georgia and southeast tennessee. <P2-S3> on average, the state has 15 tornadoes per year. <P2-S4> tornadoes in tennessee can be severe, and tennessee leads the nation in the percentage of total tornadoes which have fatalities. <P2-S5> winter storms are an occasional problem, such as the infamous blizzard of 1993, although ice storms are a more likely occurrence. <P2-S6> fog is a persistent problem in parts of the state, especially in east tennessee. <SEP> <P3-S0> Tornadoes from thunderstorms are a risk, especially in the eastern part of the state. <P3-S1> 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. <P3-S2> 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. <P3-S3> North Carolina averages fewer than 20 tornadoes per year, many of them produced by hurricanes or tropical storms along the coastal plain. <SEP> <P4-S0> After the Civil War began, Governor Zebulon Baird Vance ordered the construction of breastworks around the city as protection from Union troops. <P4-S1> During General Sherman's Carolinas Campaign, Raleigh was captured by Union cavalry under the command of General Hugh Judson Kilpatrick on April 13, 1865. <P4-S2> As the Confederate cavalry retreated west, the Union soldiers followed, leading to the nearby Battle of Morrisville. <P4-S3> The city was spared significant destruction during the War, but due to the economic problems of the post-war period and Reconstruction, with a state economy based on agriculture, it grew little over the next several decades.