RENO, Nev. >> Las Vegas temperatures dropped into the 20s and high wind advisories remained in effect across much of east-central Nevada today with gusts up to 50 mph, but sunny skies began to melt off about a foot of record-breaking snow in other areas, and the Truckee River flowed through downtown Reno at its highest level in more than three years.

Remnants of the system that brought about one-fourth inch of rain to Las Vegas on Sunday also headed west, although unusually cold conditions persisted with lows dipping into the 20s on the Strip, and the teens to the north in Nye County, where a hard freeze warning was issued Monday night through Wednesday morning for Tonopah and the surrounding area.

The storm that blew through the Sierra over the weekend dropped more than a foot of snow at Lake Tahoe-area ski resorts, a total of 18 inches at Mount Rose on the edge of Reno, where more than three consecutive years of drought turned the Truckee River into just a trickle in some stretches last summer.

The second snowpack survey of the season was expected to show steadily improving conditions throughout the Sierra when it is to be released on Tuesday. In California, water officials also are scheduled to decide whether to extend mandatory conservation orders in that state prompted by the historic drought.

Snow levels for the season surpassed the 25-foot mark over the weekend at Northstar California and Kirkwood ski resorts — a total of 303 inches at Northstar near Truckee, California, according to Cassandra Walker, a spokeswoman for Vail Resorts, owner of the two Tahoe locations.

“We generally shoot for 350 inches overall, so to have reached 300 at just over the halfway-point of our season is fantastic,” she said Monday.

Squaw Valley reported 20 inches of new snow over weekend, more than 24 feet for the season there just north of Tahoe City, California.

About 30 miles downstream in Reno, the Truckee River — which had been flowing at about 300 cubic feet per second last week — surpassed 3,000 cfs on Saturday for the first time since December 2012.

It marked the “first significant peak flow event since the drought,” the U.S. Geological Survey said. The water level reached nearly 8 feet, still 3 feet below flood stage, before beginning to decline Sunday and was at about 5 feet on Monday.

Schools were delayed Monday morning due to icy roads in the Reno-Sparks area, where police responded to dozens of spin-outs and crashes but no serious injuries were reported before the system moved off toward Utah.

The 7 inches of snow recorded at Reno-Tahoe International Airport on Sunday broke the old record of 3.5 inches for the date set in 1932, the National Weather Service said.

Near the Utah line, the Ely Airport reported 10 inches of snow on Sunday, smashing the old record there of 2 inches set in 1967. The town of Baker had 17 inches of new snow in White Pine County, with 12 inches in Eureka and Goldfield, and 11 inches in Tonopah.

A lightning strike just before 3 p.m. Sunday ignited a house fire near the Las Vegas Country Club, causing an estimated $200,000 in damages. No one was home but two cats were rescued by Clark County firefighters. Trace amounts of snow were also recorded in Henderson and Boulder City, while Lee Canyon in Mount Charleston reported 15 inches of snow.

Las Vegas is also experiencing unseasonably cool temperatures with Monday’s highs in the mid-40s, about 15 degrees below normal. The average temperature for this time of year area is in the low 60s.

And there could be more to come, said Caleb Steele, a weather service meteorologist. Winter weather events tend to peak in the later months of winter, in February and March, in southern Nevada.