


Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
232 FXUS65 KSLC 160921 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 321 AM MDT Thu Oct 16 2025 .SYNOPSIS...A low pressure system will maintain unsettled conditions across northern Utah today while the south trends drier. A warming and drying trend will follow for the upcoming weekend. The next storm system will affect the area late Sunday into early Monday. && .DISCUSSION... Key Points: - Widespread valley rain/mountain snow will continue across much of northern Utah and southwest Wyoming this morning, with accumulating snow above 6000 feet. - Cold temperatures tonight will result in freezing temperatures in the western Uinta Basin, Castle County, and west central Utah near Delta. - Patchy fog is possible late tonight through Friday morning within sheltered northern valleys including the Cache and Bear River Valleys. - Roughly 80% of ensemble members show potential for another cool Pacific system to impact the region late Sunday through early Monday. An upper low lifting through the region will continue to bring fairly widespread valley rain/mountain snow to northern Utah/southwest Wyoming into the morning hours. The circulation center is evident in satellite imagery and objective analysis lifting through northeast UT/southwest WY early this morning. A plume of weak low-mid level warm advection/pseudo-trowal structure, accompanied by moisture wrapping around the back side of this occluded circulation, is resulting in a broad area of precipitation across the Wasatch Front/adjacent terrain. This precipitation is also likely lake enhanced given a GSL lake surface (~ 16C) to 700mb temperature (~ -4C per RAP analysis) differential approaching 20C. Snow levels have fallen as low as 6000ft, and snow may be mixing in as low as 5500 feet based on web cams along the Wasatch Back northeast toward Evanston. Anticipate this precipitation to persist well into the morning hours as these features are often very stubborn and tend to linger longer than expected. Eventually as the low center continues to move away from the area this forcing should diminish this afternoon. Given this duration we`re likely looking at snow totals in excess of 6" in the higher terrain of northern Utah above 8000 feet, and 2-5" below this level. This may end up including areas around Park City, although would expect the PC area to become increasingly shadowed as the low level flow takes on more of a westerly component this morning. As this system lifts out of the region later today, much cooler temperatures and clear skies may allow min temps to reach the freezing mark in portions of the western Uinta Basin, Castle Country and west central Utah including areas around Delta. Have left the going freeze products as is for now. Additionally, with today moisture would anticipate areas of fog to develop in more sheltered locations of northern Utah such as the Cache Valley and areas of the Wasatch Back. In the wake of today`s departing trough, a warming trend will ensue heading into the upcoming weekend with daytime max temps rebounding to near climo by Saturday across the CWA, then trending another 4-7F warmer by Sunday as southwesterly flow strengthens ahead of the next shortwave trough. The majority of ensemble guidance (83%) is more progressive with this early week shortwave trough, with the better upper forcing brushing by northern Utah and pushing a relatively shallow frontal boundary through the forecast area late Sunday (north) through early Monday (south). This quick hitting solution would result in a shorter window for precipitation largely confined to the northern third of the CWA Sunday night into early Monday, while a small minority (17%) of ensemble solutions are clustered around a slower and deeper wave with a better chance for precipitation across the CWA. The official forecast favors the faster solution, which brings a strong but progressive front through the area late Sunday, accompanied by a band of precipitation Sunday night, and followed by with much cooler temperatures heading into early next week. In the wake of this trough a gradual warming trend is forecast through the end of the period. && .AVIATION...KSLC...Light-moderate rain will continue through the early morning hours until around 14-16z or so, with mostly MVFR VIS/CIGs prevailing. Brief periods of IFR conditions are possible (20% chance), particularly under any lake-effect showers which will develop moreso by early morning. Showers will be much more isolated during the afternoon, but may still produce periods of MVFR conditions. Winds are likely to be light and variable through the early morning, becoming more southerly after 15z before transitioning to northwesterly sometime between 18-20z. Mountain obscuration will continue through much of the day. .REST OF UTAH AND SOUTHWEST WYOMING...Light-moderate valley rain/mountain snow will continue through roughly 15z across northern UT/southwest WY, with predominately MVFR VIS/CIGs and mountain obscuration expected. Above ~6500ft, expect snowfall with MVFR-LIFR conditions. After 15z, lake-effect rain showers may continue in the area between KSLC-KOGD, with more scattered showers developing across much of northern Utah during the afternoon. As clouds clear by Thursday evening, some valleys could experience fog development Thursday night (KLGU in particular is the most likely). && .FIRE WEATHER...A low pressure system will continue to bring valley rain and mountain snow to much of northern Utah through this morning, mainly impacting areas east of I-15. This precipitation will gradually wind down this afternoon as the storm system begins to move away from the area. With the widespread precipitation and cloud cover temperatures will run 10 degrees below normal across the north. Meanwhile drier air has spread across southern Utah overnight, which will result in increased sunshine with temperatures a few degrees below normal today. A warming and drying trend will follow for the remainder of the week and into the upcoming weekend. Temperatures will climb back to near normal by Saturday, and then trend a few degrees above normal by Sunday as southwesterly flow temporarily develops and strengthens. The next storm system will push a cold front through the region Sunday night, with much cooler temperatures expected Monday. Any precipitation with this system is expected to remain confined to northern Utah Sunday night. Another warming and drying trend will follow heading into the middle of next week. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Freeze Warning until 9 AM MDT this morning for UTZ114-120. Freeze Watch from late tonight through Friday morning for UTZ114- 115-120. WY...None. && $$ Seaman/Cunningham For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity