PHOENIX -- Let's say the radar shows a late summer storm is expected to pass by University of Phoenix Stadium in time for the sky to be clear and starry by the start of the second half of an August or September Cardinals' game.

Under the old rules, if the roof at the stadium was closed before the game, it couldn't be opened.

On Wednesday, however, the NFL's retractable roof policy was amended at the NFL owners meetings at the Arizona Biltmore so the above scenario -- during any game until the conference championship -- can be changed. Under the new rule, in place for just one season, the Cardinals -- or any home team with a retractable roof -- can decide 90 minutes before kickoff to open the roof at halftime. However, specific weather parameters set by the home team must be met with 5 minutes left in the second quarter.

Those parameters, which are set 48 hours before a game, will include maximum and minimum temperatures and wind speeds and the likelihood of any precipitation.

If the weather matches the Cardinals' requirements to open the roof, it will be opened as soon as the first half ends.

If the Cardinals don't open the roof at halftime after saying they will during a meeting 90 minutes before the game, and the weather meets the criteria and Arizona received clearance, the amended rule says the team will be “subject to discipline by the Commissioner for conduct detrimental.”

The initial rule states that the roof could be closed at any time during the game “due to the development or anticipation of a hazardous condition that threatens the welfare of participants and/or spectators.” In that case, the roof would have to be closed for the rest of the game and can be closed while play is going on.

Arizona did not open the roof for a game last season. Since University of Phoenix Stadium opened in 2006, the Cardinals are 12-10 when playing under an open roof. The roof was open for Super Bowl XLIX in February.

The rule was submitted by the Indianapolis Colts.