FXUS65 KSLC 111035 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 335 AM MST Mon Dec 11 2023 .SYNOPSIS...A couple of moisture starved weather systems will cross the region early in the week. A cut-off low pressure system will become established across Arizona for the middle to latter portion of the week, resulting dry and cool conditions across Utah and southwest Wyoming. && .SHORT TERM (Through 12Z/5AM Wednesday)...A predominantly zonal flow resides across much of the Interior West early this morning. A weak embedded shortwave is noted crossing the northern Great Basin, while further upstream a somewhat better defined shortwave is noted digging along the British Columbia coastline. Meanwhile, a narrow band of moisture extends across southern Idaho and far northern Utah, resulting in occasional light snow across the Cache Valley/Bear Lake area and adjacent terrain. The former wave will minor out this morning as it continues east, in response to modest mid level ridging ahead of the upstream wave. The band of moisture will continue to linger near the Idaho border bringing a chance of snow, while dry and warmer air aloft resides across the remainder of the forecast area. This warming will be most notable across the higher terrain as well as much of southwest Utah where valley temperatures will reach the 50s. Given the low sun angle and limited flow, warming across northern and eastern valleys is much less certain, as cold pools remained across typical areas such as the Salt Flats, Uinta Basin, and Castle Country. The 00Z KSLC sounding also indicated a fairly substantial inversion layer in the 800-750mb layer, which should remain in place today. As such could begin to see an increase in urban haze today assuming this shallow cold air remains in place. The upstream, moisture starved wave is forecast to move inland across the Pacific Northwest today, then slowly dig into the Great Basin tonight before evolving into a closed low across Nevada Tuesday through Tuesday night on its way to the Desert Southwest. Given the lack of moisture any chance for precipitation is minimal. Temperatures aloft will cool, however again with limited sun angle and very weak flow any valley inversions may be tough to mix out through Tuesday. Tuesday night, as this low makes its way toward Arizona, there is some potential for locally enhanced canyon winds along the Wasatch Front/Cache Valley within a region of fairly modest easterly flow aloft. This will need to be monitored, as although a stronger downslope event looks unlikely, certainly could see advisory level wind gusts near typically prone areas of the northern Wasatch Front and Cache Valley owing to modest low level cold advection and a somewhat favorable pressure gradient. .LONG TERM (After 12Z/5AM Wednesday)...A cut-off low centered over Arizona looks to largely play little part in the weather forecast across Utah mid-week, aside from some colder temperatures it'll pull down Thursday morning. The Bear River Valley will be particularly chilly with lows forecast into the single digits. The cooldown will be fairly short lived as high pressure is forecast to build in for the remainder of the week; ushering in warmer air from the southwest. This ridge of high pressure is forecast to be in place through the weekend and allow for continued mild weather conditions and seasonal to slightly above seasonal temperatures across the region. && .AVIATION...KSLC...Lights winds are expected to persist throughout the forecast period. Lowered CIG between 050 and 070 are expected until 18z with improvement thereafter. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected throughout the forecast period across much of Utah. LGU is forecast to see a period of MVFR CIG today with snow showers nearby along with Southwest Wyoming (also forecast under MVFR CIG) through the early afternoon hours. Additionally, several forecast models are calling for ~25% chance for freezing rain at EVW this evening. At this time, confidence is not high enough to include in the 12z TAF package. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ SHORT TERM...Seaman LONG TERM...NDeSmet AVIATION...NDeSmet For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity