013 FXUS65 KSLC 091507 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 907 AM MDT Wed Jul 9 2025 .UPDATE...Updated for aviation discussion. && .SYNOPSIS...Hot and mostly dry conditions will persist over Utah and southwest Wyoming today, with a few high based showers developing over the higher terrain this afternoon. A weakening storm system will cross northern Utah and southwest Wyoming tonight into early Thursday, bringing temperatures back closer to seasonal normals. High pressure will rebuild by the weekend, bringing another warming trend. && .SHORT TERM (Through 12Z/6AM Friday)...High pressure remains parked over the Desert Southwest this morning as the low that has been hovering off the Pacific coast over the last few days moves onshore over northern California. Utah and southwest Wyoming remain under a warm southwest flow aloft, with high temperatures again expected to average around 10F above seasonal normals this afternoon. The trough is on track to move into the Great Basin this afternoon as it weakens. The trajectory of the system will move the persistent dry slot away from the area, allowing some mid and high level moisture to start to advect in, enough for a few high based showers to develop over the higher terrain this afternoon and into the early evening. As the low moves closer, the flow aloft will also increase, resulting in some breezy conditions, particularly over western Utah. This will combine with the hot and dry airmass to produce areas of critical fire weather conditions over portions of southern and western Utah, where a Red Flag Warning is in effect. See the fire weather section of the AFD for more details. Guidance is in good agreement that the weakening trough will track across northern Utah and southwest Wyoming tonight into early tomorrow. Given the weakened state of the system and overall lack of moisture and dynamics, associated shower activity will be minimal at best. The system will, however, bring a cold front through, bringing a noticeable change in temperatures for Thursday, particularly for northern portions of the forecast area. Those areas will see around 10F of cooling, bringing maxes back around to near seasonal normals. Cooling over southern Utah will be more limited, a few degrees at best. .LONG TERM (After 12Z/6AM Friday)...The period starts with dry westerly/northwesterly flow aloft and surface temperatures a few degrees below normal across northern Utah/SW Wyoming. However, across southern Utah temperatures will be a few degrees above normal given the proximity to a ridge centered over southern California. High pressure will remain centered over California through the weekend and into early next week. This will keep conditions dry with gradually warming temperatures across northern Utah while southern Utah keeps temperatures between 105-108F. Guidance is starting to hint at a breakdown in the ridge and potentially re-orienting further to the east to allow for a return of some moisture by the middle to the end of next week. The signal is still pretty weak which would likely limit the magnitude and extent of the moisture to the terrain of southern and central Utah. However, the latest CPC forecast does have a better monsoon signal in the July 16-22 time period across Arizona and southern Utah with lower probabilities (but still favoring wetter) the further north you go. && .AVIATION...KSLC...Predominantly VFR conditions will continue today/tonight, though with a complicated and lower-confidence wind forecast. Southerly wind gusts will increase this morning, with a low chance (10-40%) of a lake breeze sneaking in between 19 and 23Z which would turn winds northwesterly. Between 22Z-01Z, expecting deeper cumulus and vicinity showers to form with a threat of outflow winds and a likely switch to northwest winds. There is a very low chance (<20%) of continued southerly winds into the evening. A cold front will push through between 3 and 6Z turning winds to consistent northwesterly and clearing skies for the rest of the night. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for the entire airspace throughout the period. Southerly winds will be gusty for most locations during the day ahead of a mostly dry front. This front will push through the northern airspace during the afternoon/evening with isolated (~20% chance) high-based convection across the north and east portions of the area. The primary impact from these will be gusty outflow winds with very little rain possible. && .FIRE WEATHER...High pressure centered over the Desert Southwest will maintain a hot and dry airmass over Utah today. As a Pacific storm system moves into the Great Basin during the day, southwest winds will increase, producing areas of critical fire weather conditions during the afternoon and evening across southern and western Utah. With a small increase in mid-level moisture with and ahead of the trough, anticipating a few high based storms focused over the higher terrain this afternoon and evening, with gusty winds and isolated dry lightning the main threats with any storms that develop. The trough will pass across northern Utah in a weakened state late Wednesday into early Thursday, bringing more seasonable temperatures behind it but little in the way of precipitation. High pressure will then rebuild for the upcoming weekend, bringing continued dry conditions and another warming trend. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Red Flag Warning until 9 PM MDT this evening for UTZ492-493- 495>498. WY...None. && $$ SHORT TERM...Traphagan LONG TERM...Mahan AVIATION...Van Cleave FIRE WEATHER...Traphagan For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity