As Tropical Storm Hilary moves through the United States, here are six things you should know.
The location of the landfall does not change the impact of the storm. Hilary has made landfall in Mexico, but the expected impact in the United States is the same, with damaging winds, strong waves and, in some areas, major flooding.
The deserts of Southern California may be hit directly by the storm. Although there was little rain in the deserts on Sunday morning, the rain was expected to intensify this afternoon and into the evening.
The rain is picking up in the United States. As Hilary approaches the United States this afternoon, winds and rain are increasing across the Southwest. This morning, rain was already falling in San Diego and Los Angeles. Forecasters said they were already experiencing hourly rain rates of a quarter to half an inch in Los Angeles and issued a flood advisory for Los Angeles County.
Landslides, mudslides and debris flows are a worry in part because of heavy winds. In the coastal mountains, winds could still gust to hurricane force (74 miles per hour or greater). The strong winds in the mountains, combined with heavy rain, could increase the risk of landslides by uprooting trees that hold up the saturated soil along the hillsides.
In the United States, the rainfall will affect more than just Southern California. As the storm sweeps northward through the night and into Monday, rainfall will also spread into the Mountain West. Forecasters with the Weather Prediction Center believe it is probable that Hilary will be the wettest known tropical cyclone, or remnant of a tropical cyclone, to affect Nevada, Idaho and Oregon.
Monday should be calmer. With the storm moving so quickly northward, things should taper off quickly overnight, first in the south and northward through the day on Monday.