Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
809 FXUS65 KSLC 120838 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 238 AM MDT Sun May 12 2024 .SYNOPSIS...As a low exits into Colorado, high pressure will build over the Great Basin today, bringing a continued warming trend and drier conditions than the past few days. A weak storm system will graze northern Utah late Monday afternoon into the evening before another system moves through the area Tuesday into Wednesday, bringing less warm and more unsettled conditions. High pressure will return late in the week. && .SHORT TERM (Through 12Z/6AM Tuesday)...Radar has finally cleared out early this morning as a slow moving low pressure system has finally made its way into western Colorado. Behind the exiting trough, low pressure is building over the Great Basin with the ridge axis on track to move into Utah by this evening. With the ridge building, Utah and southwest Wyoming will see a drier and noticeably warmer day today with maxes averaging 5F above seasonal normals. Despite the ridge moving in, enough instability will linger over the eastern half of the area to result in primarily isolated convection east of I-15 this afternoon and into the early evening. Gusty winds would be the main threat with any storms that develop. By Monday morning, the ridge is expected to flatten as a weak Pacific Northwest system moves over the top of it. This wave is expected to graze northern Utah late Monday afternoon into the evening, bringing a bit of cooling along with an increase in shower activity, primarily for areas near the Utah/Idaho border. However, given the relatively late time of arrival of the system much of the day will be quite warm, with temperatures topping out around 10F above normal for this time of year. .LONG TERM (After 12Z/6AM Tuesday)...A Tuesday cold front remains in our forecast with a trough of low pressure forecast to impact the region. The front is not bringing too much upper level support with it, so this will be one of those `you`ll notice the wind shift and cooler temperatures behind it if you`re watching for it` otherwise you won`t notice. Ensembles are not especially impressed with this trough/front. It is at least showing up now as a weather feature when it wasn`t yesterday, so confidence that a trough/front with some degree of strength will pass through the region Tuesday has increased. Now, how much that`ll really impact the region still, unfortunately, isn`t clear. The boundary still looks likely to stall somewhere in the state through Wednesday. Let`s break down some scenarios though for Tuesday`s forecast. The most likely scenario we are looking at involves a split across west and eastern Utah. A mostly dry forecast would be anticipated across western Utah, whereas showers and thunderstorms become more likely in eastern Utah (40% likelihood or greater). Another scenario (about a 15% chance of happening and most favored by the Canadian model) involves a very wet forecast south of I-70 and a dry forecast north of there. These would be showers and thunderstorms during the afternoon and early evening hours only when daytime heating allows for building, which happens to coincide with the forecast frontal passage by the Canadian model. Thursday into Friday`s forecast thankfully has some semblance of a consensus now; indicating a building ridge from the west and thus warming temperatures and dry conditions. Headed into the weekend continues the hodge podgeyness of model solutions from yesterday where confidence in the forecast lowers as a result. && .AVIATION...KSLC...VFR conditions are forecast throughout the day. Light southeast winds are forecast to shift northwest early this afternoon with flow returning from the southeast in the early evening. .REST OF UTAH AND SOUTHWEST WYOMING...High based clouds and light winds are forecast today allowing for VFR conditions across the region. && .FIRE WEATHER...The low pressure system that had been impacting the area over the past few days has moved into Colorado, allowing high pressure to build over Utah. This will result in noticeably warmer temperatures today will less in the way of shower and thunderstorm coverage than seen the last couple of days, but isolated storms are still anticipated over the higher terrain of northern Utah this afternoon. The ridge will flatten Monday as a weak storm system grazes northern Utah, bringing a greater chance of storms to areas near the Utah/Idaho border. Another system will impact the area Tuesday into Wednesday, bringing less warm temperatures and increasing coverage of showers and thunderstorms. High pressure is expected to move back in late in the week and into the weekend, bringing drier and warmer conditions. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ SHORT TERM/FIRE WEATHER...Traphagan LONG TERM/AVIATION...NDeSmet For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity