A monsoonal pattern can bring heavy rain to the southwest United States during the summer season, including northern Nevada from time to time. A monsoon is a seasonal reversal of wind, not always a heavy amount of rain. During the summer months, ocean waters are cooler than land, allowing the wind to flow onshore. Wind flows from cold to hot. While the monsoonal pattern is more persistent in states like Arizona, depending on where the ridge wobbles we can get some monsoonal moisture in the Truckee Meadows as well. Storms usually fire on the outside of the ridge, along the boundary. We've had a mainly dry and cooler summer overall, thanks to a more troughy pattern along the west coast in July. This weekend the ridge to our east will be close enough to create a pathway for the moisture to travel into our area.
There will be thunderstorms south of I-80 in Mono and Mineral Counties on Friday, with the moisture expanding northward over the weekend. The bulk of the storms will fall early next week on Monday and Tuesday. The atmosphere gets more saturated each day it rains. While there will be plenty of moisture to work with, cloud cover could limit the size of storm coverage the next several days. It won't take a ton of sunshine to fuel storm chances, but we at least need some. The morning will be dry overall, with storms starting to develop by early afternoon. Running from south to north. The image above shows the amount of water vapor we will have to work with, which is a good amount for our area. Lowering the fire risk.Â
Flash flooding is possible due to the abundance of moisture to work with, but it won't be widespread. Burn scars will be the most susceptible to any flash flooding. The same spots that saw flooding a few weeks ago could seeing flash flooding again the next several days. Now is the time to clear any drains of debris, as ponding on roadways is possible. If you see any water it's best to turn around and not drive through it. Rain totals will vary from nothing to over an inch. Heavy downpours are possible, and the same spot could see more than one downpour in one day. While the thunderstorms will be scattered, they will also be numerous by late Sunday. Some overnight thunderstorms are possible too. River flooding is not a concern at this point, but there is a good chance of ponding on roadways with poor drainage.Â
