A significant trough and storm system is expected to develop in the Northwest on Tuesday, according to an August 31 report from OpenSnow. This weather pattern will bring cooler temperatures, 1-2+ inches of rain, and high-elevation snow to the region.
In Utah, cooler weather is expected to continue. Monsoonal moisture is forecast to trigger afternoon showers and thunderstorms on Monday and Tuesday. Monday is expected to see the highest moisture levels, with thunderstorms potentially producing lightning and heavy downpours that could lead to flash flooding. On Tuesday, showers and storms will be less frequent and will mainly affect Northern Utah, the Wasatch, and the Uintas.
The forecast for Utah indicates that drier air will move in on Wednesday and Thursday, leading to increasing winds. While a few afternoon or evening showers and storms may develop on Wednesday, Thursday is expected to be mostly dry and pleasant with temperatures gradually warming toward near-average conditions. By Friday, increased monsoonal flow is expected to bring light moisture to southern and eastern Utah, bringing a few areas of showers and storms and increasing winds.
In the Pacific Northwest, the storm is expected to bring widespread rain, with accumulations of 1-2 inches and some areas seeing near 3 inches. Snow levels may drop to near 7,000 feet, with the highest peaks potentially seeing over 6 inches of snow, and Washington seeing over 1 foot. In the Southwest, monsoonal activity will be widespread on Monday, with the heaviest rain likely in Northern Arizona where flash flooding is a possibility.
The storm system is expected to gradually weaken by the end of the week, leading to drier and warmer conditions. In the Northwest, the trough is expected to continue through the weekend before dissipating and allowing for dry conditions to develop by Sunday.
