It’s a very simple weather forecast for the next several days. A building ridge of high pressure will keep our temperatures rising, into the low 80s Wednesday, mid-80s Thursday and near 90 degrees by Friday and Saturday. The ridge will allow some overrunning cloudiness late Wednesday through Thursday, with mostly sunny skies Wednesday, Friday and Saturday. Winds will be light. Things will get warm enough to give us a shot at a high temperature record Friday or Saturday.

sponge

Yesterday, I mentioned a “demonstration” of the rain shadow when a sponge is wrung out over the head of “Mt. Kevin.” Here’s where analogies can do more harm than good. “All the water is wrung out of the clouds, and there’s none left to rain on the other side.” Can the kids relate to this? Sure. Does it illustrate any accurate scientific principal? No… In fact they will always mis-understand how downslope heating occurs; thinking that all the water in the air is gone, which of course is ludicrous. (If the Sierra took all the water out of the air, then how could it snow in the Wasatch or Rocky Mountains?) Just because an analogy is memorable doesn’t make it good.

Air on the leeward side is warmed as it descends, and therefore is

Air on the leeward side is warmed as it descends, and therefore is “drier” from a relative humidity standpoint, but there is still some moisture in it.

Advertisements