After finishing the second warmest January on record, it looks like February is on track to follow suit. A strong ridge of high pressure will stay firmly planted across the west coast keeping our skies mostly clear and our temperatures up in the 60s…not quite record levels, but pretty toasty all the same. The clear skies will allow overnight lows to drop to near the freezing mark through the end of next week. The only possible bump could be late next week as a low pressure center could drop back in from the northeast, but unless it cuts back farther to the west than the models are presently showing, all it will do for us is cool us down a bit.
Why is it colder higher up in the atmosphere? We are, after all, closer to the sun up there. But the difference in the distance is so minute (the top of Mt. Everest is about .000005% closer to the sun than sea level), that it becomes a non-factor. But thermodynamics play a much bigger role. The air pressure drops as you gain altitude. The laws of physics demand that if you reduce the pressure of a gas, it will cool. In a dry (and mixed… we’ll ignore inversions for now) atmosphere, the air will cool approximately five degrees F for every 1,000 feet of altitude gain. In a saturated (inside clouds) atmosphere, the rate drops to about three degrees per thousand feet.