A Springfield MO TV station has a free weathersite for educators. KY3 Weatherschool site has a mad science video and several printable pages, puzzles and games.
Also, teachers in the Springfield area can sign up for the KY3 Weatherschool Forecasting Contest, including Homeschoolers! (starts Feb 4, ends Feb 22).
If you use this unit, perhaps you or your children can figure out how it is that on Monday it was 74 degrees and on Wednesday we awoke to snow and below freezing temps???