Temperatures will still slowly (very slowly) drop as we go through the week, with the low-90s on Wednesday dropping to the mid-80s by the weekend. A light to moderate southwesterly flow will allow variable amounts of cloudiness to be pulled up from both Arizona and offshore, but it should be stable enough that there is almost no chance that we will get any precipitation out of it. By the beginning of next week, most of the clouds should clear out and we should see a return to sunny skies.

Conductionradiation

Yesterday we asked how frost could form in above freezing temperatures. At night, the ground loses heat two different ways; conduction and radiation. (I know that I will get some e-mails claiming that heat can transfer by convection as well, and it can, but convection doesn’t apply to solids…only liquids and gasses and therefor doesn’t apply in this case.) Conduction is when heat transfers from one substance (the ground) to another (the air) by direct contact. Pick up a chunk of cold steel. Your hand will get colder, and the steel will get warmer. Heat is being transferred by conducting from your hand into the steel. Without any other forces acting on the system, the temperature of the ground and the air would become the same because they are in contact with one another. Tomorrow, I’ll tell you how radiation throws a monkey wrench into the works.

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