Las Vegas – Yes, Vegas – Is in the Cone of Hurricane Hilary

Hurricane Hilary is barreling down an unusual path that forecasters say will bring the intense storm through the heart of the Southwest on Monday – including potentially directly over Las Vegas, Nevada.

The storm system was upgraded Friday morning to a major Category 4 with sustained winds near 140 mph and enough power to cause "catastrophic damage," as it strengthened off the western coast of Mexico.

Hilary is expected to weaken by Saturday, however, and could be a tropical storm by the time it reaches southern California on Monday.

Still, Hilary threatens to dump heavy rains and flash flooding beginning Saturday in southern Nevada, with the cone of the storm projected to come close to the nation's gambling capital in an extremely unusual weather event.

A flood watch has been issued for Las Vegas from Saturday morning through 5 p.m. Monday, according to the National Weather Service.

Forecasters warned that "excessive runoff" could cause rivers, creeks, streams and other "low-lying and flood-prone locations" to overflow.

According to KLAS, the storm could bring as much as three inches of precipitation to the region, with plenty of moisture reaching as far as Reno. The highest rain totals are expected in the state's mountainous areas, the outlet reported.

Heavy rain was expected through Monday, and a chance of showers remains possible for Tuesday, according to the weather service.

The Las Vegas area, which has been sweltering through an extraordinarily hot summer, is also expected to see a dramatic temperature drop thanks to cloud coverage as the storm rolls through.

A high of 102 degrees Fahrenheit is expected Friday, before temperatures swing down to a high of 87 degrees on Saturday, followed by 79 degrees on Sunday.

According to KLAS forecaster Sherry Swensk, Sunday could set a daily record low for a high temperature.

“We will be flirting with records for the coolest high, which is 78 degrees set in 1957," Swensk said.

Forecasters say flash flooding will be the biggest concern posed by Hilary across the desert-heavy Southwest, as the storm passes through California, Arizona, and Nevada.

Nearby Palm Springs could receive as much as seven inches of rain over 72 hours.