308 FXUS65 KSLC 062146 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 346 PM MDT Mon May 6 2019 .SYNOPSIS... Isolated to widely scattered showers and thunderstorms will diminish this evening. A slow moving storm system will bring scattered to numerous showers and thunderstorms Tuesday through Thursday across much of the state and into the weekend across southern Utah. && .SHORT TERM (Through 00Z Friday)... Showers and thunderstorms have again developed diurnally across Utah today with the best concentration of storms across far northwest Utah and along the central Mountains near Castle Country. This is the result of steadily increasing mid-level moisture ahead of a weak low pressure system that can be seen moving across California today. Low-levels remains dry, which is resulting in elevated convection producing gusty and erratic outflow winds. Strong to severe microburst potential remains limited today by the only modest CAPE aloft which will limit precipitation loading potential. Showers and thunderstorms will diminish with the loss of heating overnight, with temperatures remaining mild overnight. On Tuesday, the aforementioned low will weaken to an open wave across northern Arizona while a northern stream shortwave digs toward northern Utah from the Pacific Northwest. The resultant broad cyclonic flow and trough across central Utah will help concentrated shower and thunderstorm chances over much of northern and central Utah. BUFKIT profile show an increase in overall moisture and slight lowering of the LCL heights as the boundary layer starts to cool and moisten some. This will start to lower the gusty outflow wind threat although not eliminate it. Storms will also be relatively slow movers, with mean steering flow winds less than 10 knots across much of northern and central Utah. While heavy rain parameters are otherwise not ideal, the slow storm motions could result in locally heavy rainfall and isolated flooding potential. Wednesday will be very similar in terms of showers and thunderstorm coverage with perhaps slightly more moisture in place to work with. Temperatures will cool to 5-10 degrees below normal by mid-week as troughing continues to be reinforced by northern stream shortwaves carving out into the Great Basin. By Thursday, the broad troughing will start to cut off into a closed low over the dessert Southwest. Shower and thunderstorm chances will shift farther southward, concentrating more across southern and central Utah. Temperatures will remain below normal. Will need to continue to monitor for potential marginal canyon and or downslope winds event along the northern Wasatch Thursday as the low drops to our southwest with increasing easterly flow and cold advection from southwest Wyoming into northern Utah. .LONG TERM (After 00Z Friday)... A complicated, but typical shoulder season pattern will continue into the long term portion of the forecast. At onset, an upper level will shift westward across Nevada through the evening Thursday as another upper level low approaches the California Coast, supported by the southern jet. The short term discussion will detail the threat for gusty canyon and/or downslope winds extending into Thursday evening. These waves will eventually gradually consolidate and then shift eastward this weekend. Given the location of the deformation axis and weak subsidence, precipitation will likely be focused across the southern half of Utah for much of the Friday to Saturday period. These systems are not cold...so snow levels will remain high through the extended forecast...matching typical May levels. Upper level ridging is expected to build into the Great Basin Sunday into early next week with yet another upper level low forecast by much of the global/ensemble guidance by Thursday. && .AVIATION... West winds early this evening at SLC could also become erratic and gusty as showers pass near the terminal. There is a 20 percent chance of direct impact to the terminal, with cloud bases likely remaining above 7000 feet. Mountain obscurations are possible. Winds will return to the south/southeast around 02-03Z. Winds will remain southerly overnight then become west to northwest after 18-20Z Tuesday. Showers and thunderstorms will become more numerous on Tuesday which could result in mountain obscurations and as well as gusty and erratic winds Tuesday afternoon. Cloud bases may dip below crest level (6000 feet) at times Tuesday afternoon. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ SHORT TERM...Church LONG TERM...Kruse AVIATION...Church For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity For frequently asked questions about the Area Forecast Discussion visit... http://weather.gov/saltlakecity/general/afd_faqs.php