The "7% for every 1°C" rule (sometimes cited as 6-7%) is an empirical observation derived from the Clausius-Clapeyron equation. When you plug in the relevant physical constants for water (like the latent heat of vaporization) and consider typical atmospheric temperatures, the equation shows that saturation vapor pressure indeed increases by roughly this percentage for each degree Celsius of warming. 

Which at the end of the day leads to some crazy weather.  These images from China are unbelievable.

The "7% for every 1°C" rule. 

New York is being submerged with gushing floodwaters as torrents were seen flooding the city's subway system.

It comes after a state of emergency was delcared across New Jersey on the US' east coast after flash flooding.

In New York City, subway commuters have shared apocalyptic videos of murky floodwaters gushing out like a geyser close to the turnstiles as passengers watch on in horror from inside the carriages. A flash flood warning was announced this morning for the areas of New York, Brooklyn and Manhattan, which will stay in place until 9.45pm.

Meanwhile, in New Jersey, communities are cut off after the downpours worked their way east across the state.

And once in 100 year floods can now happen every year.

2.64 inches was recorded in Central Park, over an inch more than the previous record of 1.47 inches set in 1908.

The NOAA Atlas 15 Informational Page

American Resiliency


A cloud with a silver lining.