battle with HYDRA hampered by snowstorm

[ladyhatshepsut.livejournal.com]

Trying to locate a story I though I'd saved but can't find (yeah, again).  The Avengers (& SHIELD members?  Probably Phil and Maria with a small team) are trying to stop an attack by HYDRA.  I remember Widow and/or Hawkeye coming in through an upper window or roof vent.  The location is isolated by a severe snow storm; it's either a mall or an airport, a place with a lot of open spaces and a lot of people.  I think Hawkeye was apart from his teammates and out in the snow, either attacked by a part of the HYDRA team or following them outside and taking them out (or both).  Thanks loads.