Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
024 FXUS65 KSLC 272145 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 345 PM MDT Wed Aug 27 2025 .SYNOPSIS...Lingering moisture will maintain showers and thunderstorms with locally heavy rain today. A drying trend will then result in a decreasing threat of precipitation into the weekend. && .DISCUSSION... Key Messages * Isolated Flash Flood risk continues across portions of northern Utah, Castle Country, the San Rafael Swell, Western Canyonlands, and Capitol Reef through this evening from scattered showers and thunderstorms capable of producing locally heavy rainfall. * A day-to-day drying trend through the end of the week and into the weekend will bring a decreasing trend in daily shower and thunderstorm coverage, with any storms becoming more tied to the terrain with time. * Temperatures will run 5-10 degrees below normal through the end of the week and will then moderate back to seasonal values next week. This afternoon, monsoon moisture remains in place across the region, with the highest PW values across northern Utah with values to around 1 to 1.1 inches. Meanwhile, subtle drying is working into southwest Utah with PW values trending down to around 0.8. However, despite the slight downward trend across southern and eastern Utah, low-level moisture remains in place with many surface dew points in the 50s contributing to CAPE values of 250 to 500 J/kg. This CAPE/PWAT combination places us generally on the lower end of the thermodynamic space for flash flooding, but the recent wetting rains and low-level moisture being already in place means that efficient warm rain processes are possible on already wet soils in the area, which is helping raise the risk of flash flooding slightly. A Flash Flood Watch remains in place across the eastern basins such as Castle County, the San Rafael Swell, Western Canyon Lands and Capitol Reef into this evening. Through the end of the week, the light westerly flow will allow for continued slow drying trend into the weekend. However, daily shower and thunderstorm chances will continue Thursday and into Friday, with the best drying moving into the area by Saturday and Sunday which will finally largely shut down the daily showers and thunderstorms in time for the holiday weekend. Temperatures will also start to trend closer to seasonal averages later in the weekend and into Labor Day as ridging builds over the area. Precipitation chances will start to return by mid to late next week as the ridge axis overhead early in the week starts to drift a bit more eastward. The best moisture axis with this ridge placement will be west of the area keeping us on the fringe of the deepest moisture. && .AVIATION...KSLC...Scattered showers and thunderstorms will bring locally heavy rain into the evening hours. Thunderstorms will diminish, but isolated showers capable of locally heavy rain will last through around 09Z. Nearby showers will bring mountain obscuration. Rain showers will bring varying wind directions, but prevailing winds will be from the northwest through around 03Z. Light southeast winds are likely after 03Z. .REST OF UTAH AND SOUTHWEST WYOMING...Scattered showers and thunderstorms, primarily for southwest Wyoming and northern Utah, will be capable of locally heavy rain into the evening hours. Precipitation will be more isolated after 03Z, but showers will be capable of locally heavy rain through around 09Z. Showers and thunderstorms will be more isolated for other portions of Utah, but be capable of locally heavy rain. Winds will be relatively light, but thunderstorm wind gusts will peak around 30-40 knots. && .FIRE WEATHER... Monsoon moisture in place across the area will bring another day of scattered showers and thunderstorms across Utah, which will be efficient heavy rain producers. Thus anywhere where stronger storms track will have a high chance of experiencing wetting rainfall again today, along with an isolated flash flood risk. Showers and thunderstorms will be most limited over far southern and southwestern Utah where drier air is already starting to work its way into the area, which will become the trend across the entire state through through the end of the week and into the weekend. In the wake of the monsoon surge, temperatures will remain around 5 to 10 degrees below normal through the end of the week and into the weekend. While RH values will remain elevated today, the drying trend will continue through the end of the week with more widespread minimum RH values in the teens returning this weekend into early next week. As this occurs, the daily shower and thunderstorm chances will trend lower and become more confined to the terrain. Temperatures will also trend warmer this weekend, returning to near-normal values by early next week. Not currently expecting any elevated fire weather concerns into week as winds appear to remain light through much of the forecast period. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Flood Watch until 9 PM MDT this evening for UTZ120-121-129-130. WY...None. && $$ PUBLIC...Church AVIATION...Wilson FIRE WEATHER...Church For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity