- Dark stormclouds descended on New York City Tuesday afternoon.
- Summer thunderstorms are fuelled by hot, humid conditions that push more warm air up into the atmosphere, where it brews moisture and builds an unstable environment, creating the perfect recipe for a big storm.
- The hot weather phenomenon is projected to only get worse, as the planet warms up.
Around 2 p.m. on Tuesday, New York City descended into a cloud of darkness.
The skies opened up, thunder rained down, and lightning flashed across the sky.
Photojournalist Gary Hershorn snapped this image from Hoboken, New Jersey, across the Hudson river from Manhattan:
— Gary Hershorn (@GaryHershorn) July 17, 2018
Nearby, Twitter user Max Guliani spotted this gnarly cloud formation:
— Max Guliani (@maximusupinNYc) July 17, 2018
It’s all prompted by the sweltering temperatures that have been bathing the New York City region in sticky heat.
On Tuesday, New York declared a heat advisory would be in effect until 6 p.m., and the city opened up emergency cooling centres, as temperatures topped out at 86 degrees Fahrenheit in Central Park, with the humidity hovering near 70%. When it’s that hot, the steamy surface of the Earth heats up, and all that air has nowhere to go but up.
Thunderstorms form when that “warm, moist air rises into cold air,” as the University Corporation for Atmospheric Research (UCAR) explains on its website.
As more of the warm air hits the cold above, it mixes in and cools off, forming water droplets and creating a moving cell. Cooler air, in turn, falls down into the atmosphere and continues mixing with the heat, creating a perfectly dynamic system for a thunderstorm to thrive on: a mix of moisture and unstable air.
The phenomenon can be even more pronounced over cities like New York, which are laden with dark, hot asphalt and big black buildings, creating heat islands.
Scientists predict that the worst summer storms are only going to get more violent as the planet warms.So far, they have been right.
As people create pollutants, those greenhouse gases trap more of the sun’s heat, which raises the planet’s temperature.
Increased precipitation is a side effect of that process: the hotter the atmosphere gets, the easier it is for evaporation to occur on the surface of the Earth. Warmer air can also hold more water, which prompts heavier rains and more summer floods. Take a look at how much wetter the wettest storms in the US have gotten since 1958:
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