If there aren’t a lot of details in this forecast it’s because this type of pattern makes details very difficult to produce. A large hot high pressure center just east of the Great Basin will stay put, circulating moist and unstable air up through the Silver State. The general way days are going to go is partly cloudy to mostly sunny mornings, followed by increasing clouds and scattered to isolated thundershowers in the afternoons and evenings. High temperatures will likely top the triple digit mark through Friday, and could cool a few degrees through the holiday weekend, but will remain well above average throughout.
Yesterday, I mentioned that due to the “heat of vaporization,” when water (sweat) evaporates it draws energy from its surrounding in order to fuel the change of state. Since sweat is already in contact with your skin, it draws heat from your skin, your body cools down, and heat prostration is avoided. You can look at it as your body’s own swamp cooler, which is appropriate, since after a couple of days of sweating sans shower, you begin to feel and smell a bit swampy.
Now here’s where the humidity can throw a monkey wrench into the works. The faster the water can evaporate, the more efficient this cooling mechanism works. Water evaporates faster in dry air; therefore a dry heat is more tolerable than a humid heat. When the humidity is high, the body keeps pouring out sweat, but it isn’t doing much good because it isn’t evaporating very fast. This just causes the brain to signal for more water, you feel miserable, and the folks who make Right Guard put their kids through college.