Monday, June 17, 2013

Real Or Fake? How To Spot The Difference In Severe Weather Photos

As the news industry is plagued by false or exaggerated reports from Twitter and other social media platforms, so too is the weather industry. Whenever severe weather strikes, you can guarantee someone has a fake photo of it.

When it comes to weather photography, it often pays to be skeptical. After all, if both Hurricanes Irene and Sandy had produced a tidal wave taller than the Statue of Liberty, you probably would have heard about it somewhere else than on Twitter, right? (I use that example because even a NOAA employee was tricked into including that infamous screenshot from The Day After Tomorrow into her PowerPoint presentation.)
But how can you be sure that the weather photography you’re seeing is legitimate?

Unfortunately, you can never be completely sure. And perhaps if you know enough about photography and Photoshop, you can spot a fake by its pixels. But for those of us who don’t have such know-how, we can almost always use common sense just as effectively.

First, think about the landscape of the area in which the photographer claims they took the shot. If a person says that saw a tornadic supercell in New Jersey, and you’re looking at miles of wheat grass in the foreground, it’s probably a fake. (Or it could possibly be a very real photo from a very different place – like Kansas.) Through the magic of Google Maps, it’s easy to search for the location where the photo was reported to be taken and compare satellite or street view to what the background in the photo looks like. If the two look wildly different, you can probably disregard the photo.

Second, consider the conditions present that day, and think about what type of weather you would expect in that place.

For example, if you see a picture of a tornado that spans a great distance from the ground to the base of the cloud, check what LCLs are in the region on SPC Mesoanalysis. Without getting too technical, the LCL – Lifted Condensation Level – is the base of the cloud above ground level. A low base would typically be an LCL of less than 500 meters (or around 1600 feet) and a high base would typically be above about 2000 meters (or about 6500 feet). So if you see what looks like a high base in a picture, but LCLs are only around 750 meters, that may out it as a fake.

But cross-checking the photo with the ambient weather doesn’t even have to be that complicated. There isn't a good absolute rule here, but a few obvious giveaways would be lightning in a photo that is supposed to be from a landfalling hurricane (lightning is very rare in hurricanes because hurricanes are warm core systems, but lightning relies on the presence of ice suspended aloft).

And always be skeptical of a supercell with great structure that is reported to be anywhere besides the Great Plains or the Southeast. Supercells with crisp anvils, over-shooting tops, mammatus, and a rain-free base either simply do not occur in this part of the country, or on the very rare occasion they do, such features aren't visible due to topography, population, or other precipitation in the way.

And have a general idea, at least, of what a supercell (or a multi-cell, or even a hurricane) looks like. Another recent fake photo that spread throughout the interwebs was of a classic supercell hovering over the Statue of Liberty (what is it about Lady Liberty that draws people to forge photos anyway?) that was supposed to be a picture of Hurricane Sandy at landfall. A hurricane’s clouds, at least from the ground, will just look like a uniform deck of clouds, and if you know this, you will instantly identify that photo as fake.
Last, remember that photography has limitations. For example, a tornado, by definition, needs to be rotating. But a still image is obviously not going to show rotation. Don’t assume that any picture of anything hanging down below a cloud deck is a funnel.

Below is a picture I took yesterday near Tribune, KS of the smoke plume from a brush fire rising up beneath the base of an ordinary multi-cell thunderstorm. From a distance it might resemble a tornado, and with nothing but a single still picture to go on, it might be, but a video would clearly show that there was no rotation present here.

Overall, there are no hard-and-fast rules for spotting fake weather photography, but a healthy dose of skepticism, combined with an understanding of the area and its environment, will go a long way.