An unfortunate combination of sun glare and refrozen snow may have caused the multiple car crash nightmare along the Pennsylvania Turnpike in suburban Philadelphia on Friday morning.
NBC10 First Alert Meteorologist Bill Henley says one of the two factors could have played a role in the series of crashes that left dozens of people hurt and hundreds of drivers stranded along the toll road.
Using the web application SunCalc, Henley explained the very particular conditions that drivers were likely facing during this morning's commute.
"Drivers were going into brilliant sunshine because there wasn't a cloud left over from yesterday's storm. So, we had a lot of sun glare, not only because they were going directly into it, but also because there's so much fresh snow around that's also reflecting the sunlight," he said.
SunCalc is a website application that uses longitude and latitude location to calculate the direction of the sun at different times of day.
According to Henley, snow that had melted overnight may have refrozen right around the time that drivers were hitting the roads this morning.
"The other factor is, it happened shortly after sunrise and what most people don't realize is that just after sunrise is the coldest time of day," he said.
"So, overnight the temperatures were above freezing, but just after sunrise they dropped to freezing for most of the area. So, what may have been unfrozen over night may very well have been refrozen at the time of this accident."
Drivers, who spoke to NBC10.com after the pile up, also complained about icy conditions and sun glare.
Darren Weiss, 41, said he saw ice covering most of the turnpike when he was headed in to work this morning.
"I was driving eastbound on the turnpike and typically at that time of the morning, you're going right into the sun. So, the visibility was really poor," Weiss said.
"They're talking about slush, but there was really a large coating of frozen slush and ice covering the turnpike. I mean there was a lot of ice. I would say two-thirds of the road were covered in ice at the time."
Weiss says he barely escaped the massive accident, which he watched in horror from his rear view mirror. While the Pennsylvania Department of Transportation lifted the 45 mph speed limit restriction on most of the state's major interstates early this morning, Weiss believes the turnpike was not safe for driving.
"I was able to get around the accident sort of as it happened. But right behind me, you could hear it; it was almost like canon fire, the cars smashing into one another," he said.
"The cars weren't really going that fast, but it doesn't surprise me that cars weren't able to stop. I heard that they had lifted the speed restrictions, and to see all of the ice and the conditions that were out there, that was just insane to hear."