All forms of tropical weather impacts from Hurricane Hilary are expected throughout California and the desert southwest, but the FOX Forecast Center is closely monitoring precipitation rates, which could be historic in places where there isn’t usually much.
As Hilary’s moisture shield makes its way southwest on Saturday, some communities could record 100-300% of their annual rainfall in just three days.
Forecast models show that areas around Death Valley, the Anz Borrego Desert and El Centro, California could experience the heaviest rainfall compared to the annual average.
California’s mountainous regions are expected to receive the most rain, but precipitation at higher elevations is not uncommon.
If it falls on places below sea level, so be it.
Expected rainfall levels between 3 and 5 inches range from 60% to 275% of some communities’ expected annual rainfall.
In an average year, some locations get as little as 2 to 5 inches of rain, though not in just a few days.
Due to the threat of heavy rain, the region was classified in the zone with the highest risk of flash flooding.
In addition, flood monitors are on duty for about 26 million residents in four states, with the heaviest rainfall expected between Sunday afternoon and Monday evening.
Meteorologists with the National Weather Service warned that excessive runoff could cause flooding of rivers, streams and other low-lying areas.
Outdoor recreation is discouraged until the water level drops and the risk of flash floods decreases.
Desert communities do not fare well in heavy rainfall
Although Death Valley National Park averages only 2.20 inches of rainfall per year, the area experiences historic flash flooding.
In August 2022, monsoonal humidity dropped a record 1.70 inches of precipitation in just 24 hours.
The rain was enough to make history as the rainiest day at Furnace Creek and is considered a 1,000-year event.
Park wardens reported that hundreds of miles of roads were washed away and visitors were stranded until rescue workers arrived.
Despite the historic nature of the event, there were no fatalities in the sudden burst of water.