Priorities USA will air ads in the three largest markets — Philadelphia, Pittsburgh and Scranton — starting on July 5 and running through Election Day, spokesman Justin Barasky said.
"This morning Donald Trump cheered a potential economic collapse because it would be good for his bottom line and compared running a country to running a golf course," Barasky said, referring to Trump's assertion that a Brexit-related drop in value of the British pound could be good for his golf-course business in Scotland.
"We are determined to do everything we possibly can to ensure we never allow such a dangerous and divisive know-nothing to become president," Barasky said in announcing the ad purchases.
The Pennsylvania purchases bring the super PAC's television reservations to $117.5 million in nine states: Ohio, Florida, Virginia, Colorado, Nevada, New Hampshire, Iowa, North Carolina and Pennsylvania.
The Clinton campaign has announced its own six-week, eight-figure television ad buy in the eight states excluding Pennsylvania.
Priorities USA is also spending about $35 million on digital advertising and about $5.3 million on radio advertising.
The group has produced several ads, including one featuring people in Trump T-shirts reading aloud some of the businessman's more extreme comments about women, abortion and other subjects.