Snow load factors to consider are critical in cooler climates; roofing systems must be developed to deal with collected snow weight to avoid structural damage or collapse.
https://www.scribd.com/document/815498437/Why-You-Need-To-Think-About-a-Neighborhood-Roof-Covering-Business-in-Little-Rock-AR-223506
Snow load factors to consider are important in chillier climates; roofing systems need to be designed to handle collected snow weight to prevent structural damage or collapse