Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
162 FXUS65 KSLC 180936 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 336 AM MDT Wed Sep 18 2024 .SYNOPSIS...A cool and stable airmass will spread across the region today, and remain in place through the remainder of the week. A weak weather system will bring the next chance for precipitation Friday and Saturday. && .SHORT TERM (Through 12Z Friday)...A longwave trough continues to encompass much of the western CONUS early this morning. Tuesday`s shortwave trough has lifted into the northern High Plains, leaving a cool and stable airmass in its wake across the forecast area. Meanwhile, an upper low is noted upstream digging along the Pacific Coast, with considerable mid and high level cloud cover spreading across the Great Basin. The cool airmass in place will moderate a bit today, allowing max temperatures to trend 5-7 degrees warmer across the forecast area. Despite this, max temps will remain 5-8 degrees below climo this afternoon as the forecast area remains situated between the departing upper low, and the next upstream low along the Pacific Coast. This upstream low will continue to dig south through tonight, before beginning to spread inland Thursday. Cooling aloft associated with this low will spread across southwest Utah Thursday afternoon, keeping max temps several degrees below climo. Meanwhile, an axis of warmer air aloft will spread over northern Utah, allowing max temps Thursday to warm back to near climo. Any chance for precipitation associated with this upstream trough will remain west of the forecast area through the short term period, with the possible exception of the UT/NV border region Thursday night. .LONG TERM (After 12Z Friday)...The long term period will be seasonal and pleasant making for great opportunities to experience the quickly changing fall foliage. A weakening cutoff low will be moving through northern Arizona on Friday and Saturday. This will result in some diurnal showers mainly over the terrain of central and southern Utah, but amounting to little QPF totals (generally <0.1"). Temperatures will remain near normal across northern Utah/SW Wyoming while southern and central Utah will be a few degrees below normal. This low exits to the east on Saturday with some lingering light showers possible across the terrain. Beyond this low, we will remain in a light westerly/northwesterly flow regime that will keep temperatures near normal with a rogue shortwave remaining possible. Ensemble guidance is in agreement with a ridge building across the western CONUS by next week that should help warm temperatures slightly and keep conditions mostly dry. && .AVIATION...KSLC...VFR conditions will persist for the KSLC terminal through the period. Conditions will continue to dry with a some mid level clouds remaining. Light southerly winds will transition to light northerly winds during the afternoon. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for the entire airspace. A drying trend will continue with a few lingering mid level clouds across the northern airspace. Winds will remain light and variable. && .FIRE WEATHER...A cool and stable airmass will reside across the area today, keeping high temperatures 5-8 degrees below normal. Temperatures will warm slightly Thursday across northern Utah, returning to near normal, while temperatures remain cool across the south. With the stable airmass in place daytime RH will remain elevated across northern Utah, while drier air allows afternoon RH to fall into the teens across southern Utah both today and Thursday. The next weather system will impact the region Friday into Saturday as it passes through the Desert Southwest. Areas of light precipitation associated with this system will affect mainly southern and potentially central Utah during this time. With the unsettled pattern, temperatures will remain near to a little below normal through the weekend while daytime RH remains elevated. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ Seaman/Mahan For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity