Living near Boulder Colorado I’ve gotten used to hearing the expression “It sure Smells Like Snow” from the fall through the winter and into the spring.
Huh?
The reason why is called “Upslope” and when we have upslope conditions we often get pounded with new snow along the front range. The reason people say “It Smells Like Snow” is that there are huge Pig Farms east of Boulder towards Greely and eastern parts of Colorado, and during real upslope conditions the air starts to stink a little bit! Upslope conditions exist when surface air flow forces a given parcel of air uphill in our case from the East toward the West. When this air parcel travels back uphill, the ambient pressure decreases, because pressure always decreases with altitude in any fluid. Look up your Gas Laws. In a hurry, you’ll see that if the ambient pressure is lower than that of the parcel’s, the volume of the parcel must increase, and then the temperature must decrease so the parcel can assume the same pressure as its environment. The parcel is introduced into a new lower pressure. It wants to be at that pressure too, but in order to that, it must cool down. In nerd-ease, this is called adiabatic expansion. In the winter this equals a Big Powder Day.
In the Animation above you can see what a winter upslope condition looks like on radar. Notice how you can see the pattern of the weather moving counter clockwise backing into the Rockies. Time to get the board out!

Columbia University physicist Brian Greene recently chose the winner of the String Theory in Two Minutes or Less user-generated video contest… nice presentation of an abstract idea.

This is an incredible bit of Flash work which conveys some of the humbling complexity within a single human cell. Check out the majesty of the inner universe, the microtubules, the golgi!

Conception and Scientific Content by Alain Viel and Robert A Lue
Animation by John Liebler/XVIVO and Biovisions, Harvard College