December 21, 2010 6:58 pm EarthWatch Forecast: Tuesday, Dec. 21 – Evening Outlook Could we really have a White Christmas? US & World Videos 2:50 One more cool day, then warmer weather ahead 3:15 Cold night, then a big warmup this weekend 3:05 Temperatures to heat up over the weekend 2:05 Warming into the 80s by weekend's end 2:09 Big weekend warm-up expected