After one more very warm day to finish off the work week, conditions will start to cool back to more seasonable realms with the passage of a couple of (mostly) dry cold fronts. Friday’s high of 66 in Reno could drop about 15 degrees on Saturday, although the front itself will probably be devoid of any showers. Temperatures recover a bit on Sunday before a second system moves through Monday, lowering temperatures down into the 40s and giving us a slight chance of a shower. By the middle of next week, we should warm back up into the mid to upper 50s.

Dewpoint rel hum graph

I’ve always found the dewpoint is a more useful measure of the moistness of air than relative humidity. If you have a parcel of air where the dewpoint is, say, 20 degrees, the relative humidity can go from 100% at sunrise (if the temperature is 20 degrees) to about 25% in the afternoon when the temperature rises into the 50s… all without changing the amount of water in the air. But the dewpoint only changes if the amount of water in the air changes. It’s one of the reasons that we don’t generally “forecast” the humidity, because it changes so much in any 24 hour period.

 

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