Tropical Storm Hilary Prompts Surge in Flight Cancellations on West Coast, Southwest

Tropical Storm Hilary, currently threatening the southwest region of the U.S. with high winds and significant torrents, has resulted in a sharp increase in both flight cancelations and delays.

Jamie Rhome, Deputy National Hurricane Center Director, has categorized parts of California as being at 'high risk' of 'life-threatening' flooding due to the approaching storm.

FlightAware data reveals an unsettling image: 2,562 flights delayed, and 1,006 flights canceled within, into or out of the U.S as of 3 p.m. ET, Sunday.

Airports in the Southwest have borne the brunt of the disruption, with Southern California and Las Vegas experiencing the most flights cancelations due to Hilary's heavy rain and wind.

San Diego International Airport reports 37% of departures and 41% of arrivals canceled, while 20% of departures and 22% of arrivals at Las Vegas's Harry Reid International Airport have been scrapped.

Other airports in the region, like Hollywood Burbank Airport (formerly Bob Hope Airport), have seen a 41% cancellation rate for both its departures and arrivals.

John Wayne Airport in Santa Ana of Orange County reports 20% of departures and a 21% cancellation of arrivals per FlightAware.

Meanwhile, disruptions at Los Angeles International Airport have been relatively modest with cancellations accounting for 3% of departures and 4% of arrivals, although delays have hit 11% of departures and 10% of arrivals.

Moving further north, Sacramento International Airport has a cancelation rate of 24% for departures and 18% for arrivals, likewise 18% of flights have been canceled at Oakland International Airport.

Hilary, after dialing down from hurricane to tropical storm status on Sunday, is set to hit Southern California late Sunday afternoon, following landfall in Mexico's Baja California peninsula's northern zone.

Experts predict heavy rain, strong winds, and dangerous to catastrophic flash flooding in Nevada and inland California's mountainous and desert terrains where debris flows and mudslides pose severe risks.

Tornado warnings may occur in certain areas.

Southern California is under its unprecedented tropical storm warning as Hilary approaches, forcing closure of all state beaches in San Diego and Orange counties, while several areas in California, Arizona, and Nevada brace for floods and significant rains.

More than 21 million people reside in regions covered by the warnings, stretching from Los Angeles to San Diego along the coast and inland from Mount Laguna to Palm Springs, San Bernardino, and Victorville.

This is the first instance of the National Hurricane Center issuing tropical storm warnings for Southern California according to the National Weather Service's San Diego bureau.

Flood alerts cover Southern California, Nevada and Western Arizona alongside Utah, Eastern Oregon and Idaho as Hilary make its northward move into Monday.

With emergency resources prepositioned all over the region, California Gov. Gavin Newsom declared a state of emergency on Saturday, as did Clark County City Manager Kevin Schiller for the Las Vegas area.