Warm, dry days in Las Vegas expected to give way to rain chances, mountain snow and a sharp cooldown by Sunday

What happened

Southern Nevada should stay dry and warmer than usual through midweek before a storm system arrives late in the week, the National Weather Service in Las Vegas said in its weekly outlook, the Las Vegas Sun reported. The system could bring rain, snow in the mountains and noticeably cooler temperatures heading into the weekend.

Meteorologist Andy Gorelow, who issued the outlook, said the risk of significant weather is low through midweek. He said Sunday appears to be the day most likely to bring precipitation.

The forecast day by day

Early week: warm and breezy in spots

Las Vegas highs are forecast at 78 degrees Monday and 79 degrees Tuesday and Wednesday, according to the outlook. Gorelow said highs across the area will run several degrees above normal through midweek.

The weather service's risk outlook shows breezy conditions Monday in Lincoln, Nye and Esmeralda counties, and Tuesday along the Colorado River Valley, the Sun reported.

Late week and Halloween

Chances for showers and thunderstorms increase Thursday and Friday in Clark and Lincoln counties, the Colorado River Valley and Mohave County, Ariz., according to the outlook. In Las Vegas, the chance of precipitation is 5% to 15% on Friday and on Saturday, which is Halloween.

The weather service rates the risk of showers and thunderstorms as minor on Saturday and Sunday across the region. Mountain snow is possible in Clark, Nye and Esmeralda counties and in Inyo County, Calif.

Sunday: best chance of rain

The chance of precipitation in Las Vegas climbs to 30% to 35% on Sunday, Nov. 1. Gorelow said chances that day reach 80% to 85% at Mount Charleston and 55% to 75% in Pioche.

Gorelow said forecasters will refine rain totals as midweek approaches. For now, he said some areas could see a quarter-inch to a half-inch of rain, with higher amounts possible over the weekend.

A sharp drop in temperatures

Temperatures are expected to fall quickly as the system moves in. Las Vegas highs are forecast to slide to 75 degrees Friday, 72 degrees Saturday and 66 degrees Sunday, which the Sun noted is 13 degrees lower than Tuesday's forecast high.

Highs at all 21 locations in the outlook fall 10 to 17 degrees from Monday to Sunday, including a drop from 54 degrees to 40 degrees at Mount Charleston. Gorelow said overnight lows are near normal for the season, with Las Vegas lows between 55 and 61 degrees.

Wind expectations

Gorelow said no wind advisories are expected and gusts should generally stay below 40 mph, though conditions could change late in the week. Gusts in Las Vegas should peak at 23 mph Friday, according to the outlook.

Why it matters after this month's flooding

The forecast follows a record-tying storm earlier in October. The remnants of Rachel, a former tropical storm, dropped 1.08 inches of rain in Las Vegas on Oct. 11, tying the city's October one-day record set in 1947, according to the weather service. Floodwaters closed roads and stranded cars near the Strip, the Sun reported.

A separate 6- to 10-day outlook issued Sunday favors above-normal precipitation across the Desert Southwest from Oct. 31 through Nov. 4, Gorelow said. He said that outlook also leans toward below-normal temperatures in parts of the West. Residents can follow related coverage in our public safety section.

What to watch next

• Updated rain totals, which Gorelow said forecasters will refine as midweek nears.
• Late-week wind conditions, which Gorelow said could change even though no advisories are expected now.
• Sunday, Nov. 1, the day the outlook shows as likeliest for rain in Las Vegas and at Mount Charleston.
• Whether the 6- to 10-day outlook's lean toward above-normal precipitation from Oct. 31 through Nov. 4 holds.