Monday, January 22, 2007

Condensation Condescension

Today in the AZ Republic, the cover story is yesterday's snow here in Phoenix. Their headline is "Snow flurries wow valley," painting an image of thousands of Arizonans staring up at the sky with a look of amazement as a few snowflakes fall to the ground. Having grown up in Idaho, attending school in Utah, and living awhile in Montreal, I'm still used to snowy winters. I'm more amazed by 70 degree sunshine in January than I am by a winter snowfall. However, I've lived here long enough to know that it doesn't snow often, and we have a right to be excited when it does. That doesn't mean that we do not know what snow is, or that we think the temperature has to be freezing in order for snow to fall. The following was included in that "the valley is wowed" article. You may, like I did, wonder who the "Many people" they refer to are.

"Many people wondered how snow could fall through air with 40- and 50-degree temperatures in the Valley, well above freezing. National Weather Service meteorologists said Sunday that moisture particles were being lifted higher in the atmosphere, where it is very cold."Today, what happened was, there was a little bit of clearing in the afternoon, instability, small thunderstorms formed south of Prescott and near Cave Creek and Carefree, moved south and there was a down rush of wind and particles," meteorologist Hector VĂ¡squez said. He explained that all moisture in clouds starts off in snowflake form, but because the moisture was so high up in the atmosphere, it stayed colder for longer and didn't melt immediately, allowing it to remain as snow at non-freezing temperatures. It would be the same as watching an ice cube melt slowly rather than immediately on a warm surface, meteorologist Austin Jamison said."

Thank you for that ice melting metaphor, because without that I don't think I would get it.


3 comments:

Carlos said...

Dizzying, truly dizzying. Can he explain how if heat rises, the ice in a pond (being colder than water) floats to the top of the pond. If it worked like it is supposed to, the colder water is the deeper water and should freeze first at deeper temperature and force the fish up to the top of the pond and eventually freeze the water with those same fish (or members of their families) flipping madly on the ice where kids could simply gather them up and take them home to mamma.

Why not? It would be a lot easier than ice-fishing and there would be a lot warmer buns--if you know what I mean.

Aubrey said...

I'll bet that Austin Jamison could come up with a good metaphor for that.

jillmaren said...

I found myself asking these questions yesterday (howe it can snow if temps are above freezing). fortunately for me, I was able to answer them after thinking it over for a minute. But give the folks a little leeway here. Not everyone has grown up seeing seasons (I was raised in Florida! the only place WARMER than Arizona in the winter).