2023-08-18 20:06:00
Published on August 18, 2023 at 4:06 p.m.
California prepares for Hilary’s arrival. Los Angeles should avoid the worst, but the rain could create historic flooding.
Category 4 hurricane
Thursday evening, Hilary became a Category 4 hurricane, with gusts over 220 km / h. Fortunately, it was off Mexico at its strongest, and should decrease in intensity as it approaches the coasts of Mexico and California. But it will arrive with strong winds, gusts over 90 km / h in places, and above all, a spectacular amount of humidity that it is about to dump on the southwestern United States.
Densely populated places
There is talk of possible accumulations of more than 100 mm of water for the areas of San Diego and Los Angeles, which are home to more than 25 million residents. Even Las Vegas, which receives an average of one hundred millimeters of rain a year, could receive more than half that amount in a single day.
flooded deserts
But it is in certain desert areas that the problem could be the most serious. Joshua Tree National Park, for example, receives an average of 110mm of rain annually. This quantity is expected approximately in less than 48 hours. Death Valley National Park is in an even more precarious situation. The average rainfall amount for a whole year is 60 mm. 100 mm of rain in less than two days could be catastrophic for this sector.
A funnel effect
The soil there is extremely dry and compact, and does not absorb any rain. The city is surrounded by mountains, which thus act as a gigantic funnel and concentrate all this rain which therefore accumulates very quickly. In 2019, 22 mm of rain fell in 24 hours. A completely dry place in Death Valley, one of the hottest and most arid places in the world, had turned from desert to lake more than 15 km in diameter. More than four times that amount of rain is expected by Monday. Several roads could be washed away by “flash floods”.
A hiker’s nightmare
“Flash floods” are the terror of hikers in the region. Because of this funneling effect of the hard-packed mountains, 10 mm of rain in a few hours can turn a stream into a dangerous torrent that cannot be reached. to escape. It goes without saying that the region is to be avoided during the next few days.
With the collaboration of Carol-Ann Veilleux, meteorologist.
SEE ALSO: Hurricane winds cause major damage in Florida
1692414913
#Hurricane #Hilary #turn #Death #Valley #huge #lake