Most of central and north Tempe was built out decades before the subdivisions of Gilbert and Chandler, and the roofs show it. Neighborhoods like Maple-Ash, Holdeman, and University Park are full of flat and low-slope roofs covered with built-up roofing or spray foam. Those systems work when they drain. When monsoon rain or haboob dust clogs a scupper or a roof drain, water sits on the roof, finds a seam, a cracked foam coating, or a failed penetration seal, and enters the roof assembly. On a flat roof, water can travel a long way under the surface before it stains a ceiling.
The second Tempe factor is trees. The older neighborhoods have the mature shade canopy the newer suburbs don't, which keeps houses cooler but puts large limbs over roofs, patios, power lines, and block walls. A microburst that would only rattle a young subdivision tree can bring down a heavy limb here, and a limb through a roof is an open hole in the next storm.
Third is who lives in the house. Tempe is dense with rentals, condos, and student housing, and a storm leak in a tenant-occupied home gets reported later than the same leak in an owner-occupied one. Every hour an opening stays unprotected adds to the drying and repair scope. We restore all of it, from emergency tarping to rebuild, with documentation that works for owners, landlords, property managers, HOAs, and adjusters.