The acting U.S. ambassador to Ukraine told lawmakers that Sondland personally communicated the demand for a political favor to Ukrainian officials.
The freshman Democrat denied any relationship with her staffer, but admitted to having an "inappropriate" relationship with someone else before she was elected.
More than 150,000 people were without power early Monday as fierce winds and "half dollar size hail" swept through the region.
The U.S. negotiated a short cease-fire this week to stop the fighting in Syria, but the deal was largely seen as a win for Turkey.
Earlier in the day, acting White House chief of staff Mick Mulvaney confirmed Trump ordered military aid to Ukraine to be put on hold. He later denied those remarks.