Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
701 FXUS65 KSLC 141046 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 346 AM MST Fri Nov 14 2025 .SYNOPSIS...An active pattern will bring the threat of valley rain and mountain snow this weekend through mid-week next week. Temperatures will initially be around 10 to 15 degrees above normal through Saturday, falling near normal Sunday and potentially below normal by mid-week next week. && .DISCUSSION...An active pattern is expected to impact the region through much of the next week. Early morning upper air and satellite analysis indicates broad ridging remains in place across the central and southern Plains. An upper level low is noted off the central California coast. A landfalling atmospheric river is noted associated with this upper level low, impinging on the southern California coast. The upper level low will slowly shift eastward through Saturday morning, before finally ejecting ahead of the next trough in two separate pieces, on area of low pressure shifting across the Great Basin, the stronger southern part of the trough shifting across the Desert Southwest Sunday into early Monday morning. What makes this storm system somewhat unique is the association with the landfalling atmospheric river. Looking at the EFI (EC- based Extreme Forecast Index) shows high anomalies and a shift of tails across southwestern/western Utah Sunday. NAEFS PW anomalies for the same period show either maximum values for the climatology or nearly maximum values. The majority of the guidance has come into line with this system, with the major ensembles tightly clustered around the mean across the southern mountains (for Brian Head this mean is around 0.90 inches of liquid equivalent). Expect snow levels to start initially around 9500 to 10000 feet Saturday evening, falling to near 7500 to 8000 feet by Sunday evening. The period of heaviest snow for the southern mountains is expected between around 3 AM Sunday morning and midnight Sunday night. With orographics/upslope coming into play, the 25th to 75th percentile for snow totals is around 5 to 10 inches above 9000 feet, with locally up to 12 inches in the Brian Head/Tushar Range areas. From around 7500 feet to 9000 feet, the 25th/75th percentile range is around 2 to 5 inches. Right now, think amounts may warrant a winter weather advisory for the southern mountains, but will let the day shift coordinate with transportation partners before issuing any products (and given the heaviest snow won`t begin until early Sunday morning, we have some time). As far as heavy rain, some locations across southwestern and south central Utah will see around 0.50-1.00" of rain. While widespread flash flooding isn`t expected, localized flooding is possible, especially in areas where storm drains are filled with leaves. Normally dry washes and slot canyons may be running. As mention previously, the northern split of this trough will impact portions of northern and central Utah, mainly later Sunday morning into early Monday morning. PW anomalies are still quite elevated across northern and central Utah, though forcing will not be as strong. Guidance shows significantly more spread in potential precipitation amounts. For example at Alta, around 45% of ensemble members favor around somewhere around 0.50" of water equivalent and the other 55% favoring somewhere between 0.30-0.40" of water equivalent. Snow levels will start out around 8500-9000 feet Sunday morning, falling to near 7500 feet by early Monday morning. The 25th/75th percentile snow totals for above 9000 feet is around 2 to 7 inches, which is below the threshold for winter weather advisories for the Wasatch Range and near the bottom of the range for the western Uintas and central mountains. Right now, highest confidence is in a sub-advisory event for the northern and central mountains, however, with the PW anomalies as high as they are, something to monitor in guidance trends. After a brief break Monday, another potential trough will impact the region Tuesday into Wednesday. Looking at the 00Z ensembles, around 75% of the ensemble members favored a solution that would bring an upper level low across the region, with additional moderate to heavy snow for the higher terrain of Utah. Unfortunately, the 06Z deterministic run of the GFS has shifted toward the 00Z deterministic Canadian, cutting off this upper level low and shifting it down off the Baja Coast and then finally ejecting the low across the Arizona/Mexico Border. Model spread is significant to say the least with this system as to whether the upper stream trough is able to eject the cold, upper level low across the Interior West or whether the cut-off low is pushed south along offshore Baja California and then ejecting eastward well south of the area. So while there is some potential for another round of moderate to heavy mountain snow, confidence is low given substantial model spread. && .AVIATION...KSLC...VFR conditions continue at the KSLC terminal through the TAF period. Increasing mid-high level cloud cover will increase this morning as moisture increases across the airspace, with low but non-zero chances for showers to impact the vicinity of the terminal between 18-21z. Otherwise, dry conditions expected today with breezy southeasterly winds increasing out of the south this afternoon. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions persist for all regional terminals through the TAF period. Increasing mid-to- high level cloud cover is expected throughout the day across the airspace. South to southwest winds prevail at all regional terminals today, with gusty winds developing once again for most terminals after 18z. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ Kruse/Whitlam For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity