I don't have an HD radio, but here in DC, I can hear hash next to two stations:
570 WTNT Bethesda, MD (more like Germantown, a suburb about 25 miles NW of downtown DC) / 1,000 watts "highly directional" toward DC -- please
980 WTEM Washington, DC / 5,000 watts, mostly aimed away from Fairfax County, the DC area's most populous county!
Both stations are owned by Clear Channel, by the way.
So far, there are two major signals that have been online in HD, yet don't do HD at night:
630 WMAL Washington / 5,000 watts that actually provide pretty good service to DC, Fairfax Co., and most of the rest of the immediate suburbs. There's a daytime HD signal, but no nighttime HD so far.
1500 WWWT Washington / 50,000 watts aimed away from Fairfax County (though an FM signal covers them). They used to air an HD daytime signal, then took the HD off entirely for some reason.
Both of these stations aren't owned by Clear Channel.