Las Vegas Faces Gusty Winds, Thunderstorms and a Flash Flood Risk This Week as Temperatures Drop

What happened

A low-pressure system is expected to bring gusty winds to the Las Vegas area Tuesday and Wednesday, followed by showers and thunderstorms Wednesday and Thursday, the National Weather Service said Monday, according to the Las Vegas Sun. The forecast comes about 10 days after the remnants of Tropical Storm Rachel flooded streets and tied the October daily rainfall record.

Morgan Stessman, a meteorologist with the weather service's Las Vegas office, laid out the timeline in the agency's weekly outlook, the Sun reported. Southerly winds will strengthen as the system approaches, and scattered storms could hang on into Friday in eastern zones, which include Clark and Lincoln counties in Nevada and Mohave County, Ariz.

How serious the risk is

Minor overall, with possible hazards

Forecasters rate the risk from wind, showers and thunderstorms as minor on Wednesday and Thursday. The weather service still warned that the storms could produce moderate to heavy rain, localized flash flooding, sudden gusts above 40 mph and lightning. Boating conditions on area lakes could also become hazardous.

Flash flood outlook

The agency's outlook places much of the region under a marginal risk of excessive rainfall leading to flash flooding on both days. A marginal risk means at least a 5% chance of that kind of rainfall within 25 miles of a given point, the Sun reported.

A higher slight risk, meaning at least 15%, applies Wednesday only to Mohave County within the Las Vegas office's coverage area, especially its eastern zones. On Thursday, that slight risk extends into Clark and Lincoln counties.

The day-by-day forecast for Las Vegas

Rain chances and wind

The chance of precipitation in Las Vegas peaks at 65% on Thursday, according to the weather service forecast. Wind gusts could reach 28 mph Wednesday and 21 mph Thursday.

Temperatures

Highs are forecast at 82 degrees Tuesday and 80 Wednesday, then 72 Thursday and 70 on Friday and Saturday. Lows should settle at 56 or 57 degrees from Thursday through Sunday, and the weather service said cooler-than-normal temperatures will last through the weekend.

Looking further out, the agency's 6-10 day outlook for Oct. 24-28 leans cooler than normal for parts of the region, with near-normal temperatures in eastern and southern zones. It gives a 40% to 50% chance of above-normal precipitation.

Why it matters after Rachel

Las Vegas recorded 1.08 inches of rain on Oct. 11 from Rachel's remnants, tying an October daily rainfall record last matched in 1947, the Sun reported. That storm flooded streets, and this week's system brings another chance of localized flash flooding to the area. More local weather and safety updates are collected in our public safety coverage.

A wider Southwest pattern

The Sun described this week's storm as part of a larger weather pattern across the Southwest. Tropical Storm Trudy, off Mexico's Pacific coast, will keep its core wind and surge impacts well south in Mexico, the weather service said, but its leftover tropical moisture is expected to fuel several days of unsettled weather from California to as far east as Colorado.

That broader pattern carries a threat of flash flooding, high-mountain snow and elevated coastal swells, according to the weather service.

What to watch next

• Gusty southerly winds Tuesday and Wednesday as the low-pressure system approaches.
• Scattered showers and thunderstorms Wednesday and Thursday, with a slight flash flood risk extending into Clark County on Thursday.
• Possible lingering storms Friday in eastern zones, including Clark and Lincoln counties.
• The Oct. 24-28 outlook, which gives a 40% to 50% chance of above-normal precipitation.