High Quality Content by WIKIPEDIA articles! The Storm Prediction Center (SPC), located in Norman, Oklahoma, is tasked with forecasting the risk of severe thunderstorms and tornadoes in the contiguous United States. The agency issues convective outlooks, mesoscale discussions, and watches as a part of this process. Convective outlooks are issued for Day 1, Day 2, Day 3, and Day 4–8, and detail the risk of severe thunderstorms and tornadoes during the given forecast period, although tornado, hail, and wind details are only available for Day 1. Days 2 and 3, as well as 4–8 used a probabilistic scale, determining the probability for a severe weather event in percent. Mesoscale discussions are issued to give information on a region that is becoming a severe weather threat and states whether a watch is likely and details thereof, as well as situations of isolated severe weather when watches are not necessary. Watches are issued when forecasters are confident that severe weather will occur, and usually precede the onset of severe weather by one hour.