Micrathena gracilis (Spined Micrathena) ♀.
Size: approx. 9 mm. Photo: 08/15/18, noon.

Females of Micrathena gracilis have ten spines on their chunky abdomen. They are typically white or pale yellow, which makes this yellow specimen a bit unusual. Males looks very different. July and August appear to be the prime time for finding this spider. It spins a moderately large, very tightly coiled web, often in wooded or brushy areas. Despite its fierce appearance, it is completely harmless to humans. 

bug guide (these photos):