Will Tropical Moisture Bring Storms and Rain to Reno-Tahoe?

The remnants of Tropical Storm Mario are forecast to bring showers and thunderstorms to the Reno-Tahoe area later this week, with the most significant activity expected on Friday. As warm, sunny weather continues, conditions are set to change as moisture from the storm interacts with a separate upper low off the California coast, potentially resulting in heavy rain and localized flooding.

Last updated: 17 September 2023 (BST)

Key Takeaways on Potential Rain for Reno-Tahoe

Warm, sunny weather continues Wednesday.
Storm chances build Thursday night, peaking on Friday.
Thunderstorms could bring heavy rain and localized flash flooding in the Sierra and Tahoe basin.
Conditions trend drier from Sunday into early next week.

What Forecasters Say About Reno-Tahoe Storm Potential

The National Weather Service (NWS) in Reno has indicated a complex situation developing this week, with several factors contributing to uncertainty regarding storm activity. The main influences include the remnant tropical moisture from Tropical Storm Mario and an upper low pressure system off the California coast. If these systems combine effectively, storms could form in bands, especially south of U.S. Route 50, leading to heavier rainfall.

If the tropical moisture shifts further south, the Reno-Tahoe area may only experience clouds and light, sporadic showers. Forecasters have highlighted Friday as the most critical day for potential thunderstorms and heavier rainfall. Any clearing of clouds during the day could enhance the strength of these storms, leading to increased rainfall totals.

Reno's Forecast for This Week

Here’s a detailed look at the weather forecast for Reno this week:

Wednesday, 17 September: Sunny, high near 89°C. Low around 58°C.
Thursday, 18 September: Partly sunny, high near 88°C. A 20% chance of showers at night. Low around 59°C.
Friday, 19 September: Slight chance of morning showers, then thunderstorms possible after 11 a.m. High near 78°C. Chance of rain: 30%. Low around 55°C.
Saturday, 20 September: 20% chance of showers after 11 a.m., mostly sunny, high near 83°C. Low around 54°C.
Sunday, 21 September: Sunny, high near 85°C. Low around 56°C.
Monday, 22 September: Sunny with a high near 87°C. Chance of showers returns in the evening, with a low around 58°C.
Tuesday, 23 September: Mostly sunny with a chance for showers, high near 84°C.

Tahoe's Forecast for This Week

The weather outlook for the Lake Tahoe area is similar to that of Reno, with warm conditions giving way to increased storm chances later in the week. Below is the forecast for Tahoe:

Wednesday, 17 September: Sunny, high near 78°C. Low around 50°C.
Thursday, 18 September: Partly sunny, high near 77°C. A 20% chance of showers at night. Low around 51°C.
Friday, 19 September: Slight chance of morning showers, followed by possible thunderstorms after 11 a.m. High near 66°C. Chance of rain: 30%. Low around 45°C.
Saturday, 20 September: 20% chance of showers after 11 a.m., mostly sunny, high near 71°C. Low around 43°C.
Sunday, 21 September: Sunny, high near 74°C. Low around 45°C.
Monday, 22 September: Sunny with a high near 76°C. Chance of showers returns in the evening, with a low around 46°C.
Tuesday, 23 September: Mostly sunny with a chance for showers, high near 72°C.

Understanding Tropical Storm Remnants

Tropical storms can profoundly impact weather patterns far from their origin. The moisture left behind can lead to increased precipitation, particularly in mountainous regions like the Sierra and Tahoe basin. This effect occurs due to orographic lift, where moist air is forced to rise over the mountains, cooling and condensing into clouds and precipitation.

In this case, the remnants of Tropical Storm Mario are expected to interact with an upper-level low, which can enhance storm development by providing additional lift and instability in the atmosphere. Such interactions can lead to complex weather patterns, making precise forecasting challenging.

Potential Impacts of the Upcoming Storms

As the storm system moves into the Reno-Tahoe area, residents should prepare for several potential impacts:

Heavy Rainfall: Some areas may experience heavy downpours, leading to a risk of flash flooding, particularly in low-lying regions and near waterways.
Thunderstorms: The potential for thunderstorms could result in lightning strikes, strong winds, and hail.
Travel Delays: Rain and storms may affect travel conditions, particularly in the Sierra, where visibility could be reduced.
Outdoor Activities: Residents should be cautious with outdoor plans, especially on Friday when the storm intensity is expected to peak.

What to Expect After the Storm

Following the stormy weather, conditions are expected to trend drier heading into the weekend. High temperatures are projected to rebound into the 80s in Reno and the 70s in the Sierra, providing ideal conditions for outdoor activities. However, another weather system may move in early next week, but details remain uncertain regarding its strength and impact.

Residents should stay informed through local weather updates as the week progresses, especially as forecasters monitor the interaction between the storm remnants and other weather systems.

Preparing for Severe Weather

With the potential for severe weather, it's essential for residents in the Reno-Tahoe area to prepare accordingly. Here are some steps to consider:

Stay informed by following local weather updates and alerts.
Have an emergency kit ready, including supplies like water, non-perishable food, flashlights, and batteries.
Establish a communication plan with family and friends in case of severe weather disruptions.
Be cautious of local advisories regarding travel and outdoor activities during storms.

FAQs

When will the storm arrive in Reno-Tahoe?

The storm is expected to begin affecting the Reno-Tahoe area on Thursday evening, with the most significant activity anticipated on Friday.

What kind of weather can we expect from the storm?

Residents can expect showers and thunderstorms, with heavy rainfall and the potential for localized flash flooding, particularly in the Sierra and Tahoe basin.

Will the weather improve after the storm?

Yes, conditions are expected to trend drier over the weekend, with warmer temperatures returning for Reno and Tahoe.

How can I stay safe during the storm?

Stay informed with local weather alerts, prepare an emergency kit, and avoid unnecessary travel during severe weather conditions.

Is there a chance of more storms next week?

While another system may arrive early next week, confidence in its strength and impact remains low at this time.