The city of New York was struck by storms they caused intense storms (beyond 180 mm of falling rain) which caused numerous floods in the subway and in the main roads of the metropolis. Between 18:51 and 19:51 on Monday 14 July (local time, 00:51 in Italy), about New York City have fallen 52 mm of rain: It was the second most rainy hour ever recorded in the city, beaten only by the passage of the Hurricane Ida of 2021, when 80 mm of rain fell in one hour.
The intense rainfall, in reality, also involved other states of the eastern coast, including New Jersey (where the state of emergency has been declared)Connecticut and Pennsylvania: the National Weather Service (NWS), the national meteorological service, has issued flood alerts for all the districts of New York, but also for cities such as Philadelphia and Levittown (in Pennsylvania), Camden and Bergen (in New Jersey) and Chapel Hill and charcoal (in North Carolina). The torrential rains have caused delays and cancellations in the JFK airports, Laguardia and Newark, with the firefighters who had to intervene in dozens of situations to save motorists stuck in underpasses or commuters stopped in the flooded stations.
All this only happens a week from floods who hit Texas with more than 120 victimsand while the west of the USA is afflicted by a particularly aggressive fire season.
The causes of the “flash flood” in New York
To cause the event was a forehead stationary of sub-tropical origin remained blocked in the area north-eastern of the USA. The origin at low latitudes made the air of the unstable front with higher latitudes and full of humidity, two factors that can make the consequent disturbances particularly violent. The humidity in fact acts as a “raw material” for the formation of storm clouds, and the strong instability Due to the clash with cold air makes the liberation of thermal energy accumulated in the form of rainfall much faster. To this we add that it is a frontly blocked fronttherefore unable to travel great distances quickly: the consequence is that the disturbance Download rainfall in a more restricted areathus making the rains more intense.
Phenomena of this type are made more frequent and more intense by global warming. The reasons are different, but one of these has to do with theIncrease in the surface temperature of seas and oceans and the contextual Increase in air temperatures. In fact, a hot sea evaporates more, then “gives” more water vapor in the air; This, on the other hand, the more hot is the higher the amount of water vapor that is able to retain before reaching saturation.
If this hot air is full of humidity moves towards lower latitudes and meets cold air, here The conditions become unstablethe water vapor condenses into imposing storm clouds that quickly discharge excess energy also through torrential rains. Where The ground is unable to absorb water flow At the entrance, the risk of a lightning flood like the one that flooded New York becomes concrete.
The current situation: Metro flooded in New York and state of emergency for bad weather in New Jersey
In New York, public transport has returned largely operational, even if strong delays persist: according to what reported by Metropolitan Transportation Authoritythe flooding of New York undergrounds was caused by the sewage system, too ancient to manage torrential rains. Specifically, this sewage system is able to manage about 1.75 inches (approximately 44 mm) of rain per hour, but the strong rains have exceeded this capacity, with the consequent escape of water in the underground stations.
Abundant rains also made the level of the Bronx Riverwhich flows in the south-east of New York: at 6:00 on July 15, the water has reached one Phase of moderate full equal at 1.15 meters (3.78 feet), and then returns to lower over the afternoon.
As for the New Jerseyat 6:53 today 15 July (local time, 12:53 in Italy), the National Weather Service has issued a new alert for floods in the state, including the counties of Middensex and Somerset, reporting the danger of floods of rivers and streams And advising the population to avoid traveling flooded roads. Right here numerous damage was reported along the Route 22 and 28with sections of the carriageway that folded and raised, while several debris blocked the highway in both directions.
