21 June 2013

An exceptional thunderstorm measured drop by drop at École des Ponts ParisTech

by Rosa Vicari / École des Ponts ParisTech

On Wednesday afternoon, violent storms hit the Paris Region. Between 5 p.m. and 8 p.m., the Fire brigade of Paris received 6,462 calls related to the storms, a number that is usually reached in 24 hours. 1,600 of these calls concerned flood problems (huffingtonpost.fr).
These intense rainfall events were measured by the present weather sensor PWS100, recently installed on the roof of the École des Ponts ParisTech. With a return period of 10 years, the storm that occurred from 17:20 to 17:50 is an exceptional event of great interest for the researchers of the  RainGain project.

The PWS100 (Campbell Scientific) detects in real time the size and speed of hydrometeors (rain, hail, snow...) and couples this information with measurements of temperature, humidity and visibility to distinguish different types of precipitations.

With the present weather sensor and other measuring devices, such as the X-band radars, purchased with 50% of funds from the Interreg IVB NWE Programme, intense rainfall events can be observed at fine scale and can be better understood. These studies lead to a better management of the risk of stormwater floods in the city, such as those that have affected the Île-de-France Region in the last days.