Why Your Car Dashboard Says It's a Lot Hotter Than It Really Is

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iStock

When you first turn on your car in the middle of a sunny day, chances are your dashboard probably says it’s quite hot out. Like, a lot hotter than it feels. There’s a reason why car thermometers don’t always seem accurate, according to atmospheric scientist Greg Porter at The Washington Post.

Your dashboard temperature reading actually comes from something called a thermistor, which is similar to a thermometer but instead of mercury, it uses electrical current to measure changes in temperature. (Remember that temperature is an indication of how fast or slow gas molecules in the air are moving around. The higher the reading, the greater the molecules' kinetic energy.) In a car, that thermistor is located just behind the grill in the front of the car. Therein lies the problem: Your car's temperature readings come from an unusually hot location.

Asphalt roads get really, really hot in warm weather (enough so that cities become significantly hotter than their greener surroundings in the summer), so a temperature reading taken just above the surface of the road isn’t going to be super accurate. Heat radiates up from the road—as you can see on particularly hot days when the highway starts to look shimmery—and the thermistor in your car picks up that excess heat. It’s like measuring the temperature of a large room by sticking the thermometer an inch away from the fireplace.

That doesn’t mean your dashboard temperature readings are useless. When it’s not as hot out, there isn’t much interference from heat rising off the road. It’s also more effective when you’re moving—if you’re traveling down the highway, it will pick up less heat radiation from the road than if you were sitting in a parked car. However, Porter warns, the thermistor isn’t sensitive enough to distinguish between one-degree differences, which can be dangerous if you’re driving in the winter and need to know if temperatures have hit freezing or are floating just above.

In short, as nice as it is to know how temperatures are changing from one destination on your road trip to another, take that dashboard number with a grain of (road) salt.

[h/t The Washington Post]

How Waffle House Helps Measure the Severity of a Natural Disaster

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iStock

There are a lot of ways the Federal Emergency Management Agency (FEMA) assesses and addresses the severity of a natural disaster. Meteorology can predict movement patterns, wind gusts, and precipitation. Resources are dispatched to areas hit hardest by torrential weather.

But when the agency needs an accurate, ground-level gauge for how a community is coping during a crisis, they turn to Waffle House.

Since 2004, FEMA has utilized what former administrator Craig Fugate called the “Waffle House Index.” Because the casual dining chain is open 24 hours a day, seven days a week, tracking to see if a location is closed or working with limited supplies can help inform the agency as to whether affected areas are ailing or taking steps toward normalcy.

“If a Waffle House is closed because there's a disaster, it's bad,” Fugate told NPR in 2011. “We call it red. If they're open but have a limited menu, that's yellow ... If they're green, we're good, keep going. You haven't found the bad stuff yet.”

For FEMA, the ability to order a plate of smothered and covered hash browns is an important analytic. If a Waffle House is having trouble getting stock, then transportation has been interrupted. If the menu is limited, then it’s possible they have some utilities but not others. If its locations have locked their doors, inclement weather has taken over. The chain’s locations would normally stay open even in severe conditions to help first responders.

The company has opened a Waffle House Storm Center to gather data in anticipation of Hurricane Florence, a Category 2 storm expected to touch down in the Carolinas this week. But not all locations are taking a wait-and-see approach. One Waffle House in Myrtle Beach, South Carolina has already closed due to the looming threat, making it the first red dot on the Index.

[h/t CNN]

See What Hurricane Florence Looks Like From Space

NASA via Getty Images
NASA via Getty Images

As Hurricane Florence continues to creep its way toward the Carolinas, it’s repeatedly being described as both "the storm of the century” and "the storm of a lifetime” for parts of the coastlines of North and South Carolina. While that may sound like hyperbole to some, Alexander Gerst—an astronaut with the European Space Agency—took to Twitter to prove otherwise with a few amazing photos, and issued a warning to “Watch out, America!”

According to the National Weather Service, “Hurricane Florence will be approaching the Carolina shores as the day progresses on Thursday. Although the exact timing, location, and eventual track of Florence isn't known, local impacts will likely begin in the afternoon hours and only worsen with time throughout the evening and overnight period.”

On Tuesday, Wilmington, North Carolina's National Weather Service took the warning even one step further, writing: "This will likely be the storm of a lifetime for portions of the Carolina coast, and that's saying a lot given the impacts we've seen from Hurricanes Diana, Hugo, Fran, Bonnie, Floyd, and Matthew. I can't emphasize enough the potential for unbelievable damage from wind, storm surge, and inland flooding with this storm.”

Gerst’s photos certainly drive that point home.

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