Accord started shaking on highway
 

I have a 2013 accord with 30k miles. I drove on icy and bumpy local roads this morning (after the snow storm in the north east yesterday). When I got on the highway which was well plowed and clear, once I hit about 40 mph or so, my car started shaking and vibrating. It stayed that way throughout the highway stretch at speeds ranging from 40-70 mph. Once I got back on local roads, the shaking and vibrating disappeared.

Any thoughts on what the cause of the problem could be? I have a feeling driving on the very bumpy and icy roads this morning might have something to do with it - did it mess up the alignment, rotors, shocks? Thx.

Wheel balance (may have lost a wheel weight)