068 FXUS63 KLSX 022044 AFDLSX Area Forecast Discussion National Weather Service Saint Louis MO 244 PM CST Sat Jan 2 2021 .SHORT TERM... (Through Late Sunday Night) Issued at 243 PM CST Sat Jan 2 2021 Early this afternoon, the center of another storm system bearing down on our region was centered just south of KSGF, tracking E-NE. There was a weak surface reflection of this system with some cyclonic flow in southern Missouri. An area of precipitation exists around this LO center, much of it in the form of snow. There continues to be patchy drizzle/freezing drizzle and flurries ahead of this system ("snizzle") where a field of very low clouds exists. The recent trend has slowly been favoring flurries as the RGB daytime cloud phase of GOES 16 shows icing developing overhead from the pure liquid clouds that we had earlier. Temperatures around the area remained in the upper 20s to mid 30s, only a few degrees if that above early morning minimums. An upper shortwave system exists in western Wyoming tracking E-SE. Patchy dense fog has stubbornly held on to portions of northeast-central Missouri and west-central Illinois. The storm system to our southwest is expected to track E-NE through our region, mainly this evening, and will strengthen slightly as it does so. For many areas, this will facilitate a full transition from the "snizzle" to steady light snow. In the wake of the storm system, it does appear that soundings show the potential for a brief switchover to freezing drizzle before everything comes to an end. There remains good ensemble agreement from GEFS and HREF on keeping snow totals less than an inch, with some outliers showing better snow potential in IL with up to 2-3". Icing looks confined to a light glaze possible. Spotty dense fog for central-northeast MO and west-central IL is expected to expand as we head into night with an anticipated lowering of the cloud deck, and a Dense Fog Advisory has been issued until 12pm. An expansion of this Advisory may be needed further southeast. In the wake of the storm system later tonight, low stratus clouds will continue to linger and look to linger well into Sunday as well, with a general lack of anything to dislodge them or a shift in flow. The shortwave disturbance from Wyoming looks to track just south of our area on late Sunday, and with less moisture and weaker lift than the previous two systems, will struggle to produce any sensible weather when it passes. Leaned cool on max temps on Sunday with anticipated clouds for many areas, undercutting MOS values and keeping most locations in the 30s. TES .LONG TERM... (Monday through Next Saturday) Issued at 243 PM CST Sat Jan 2 2021 A mostly quiet period still looks set for much of next week, with the exception of Wednesday-Thursday, where there remains good ensemble mean agreement on a system tracking through. While a warmer pattern is also favored during this time, the system structure does appear strong enough to where it may be able to support the potential for some snow, but much of the precipitation from this is favored to be rain. Beyond Thursday, ensembles continue to mainly support seasonable temps with little to no precipitation. TES && .AVIATION... (For the 18z TAFs through 18z Sunday Afternoon) Issued at 1158 AM CST Sat Jan 2 2021 IFR conditions and light surface winds are expected to prevail at the TAF sites through the valid period. A period of snow is still expected this evening, mainly at the STL metro sites, flanked before and after with patchy freezing drizzle/drizzle. Stagnant conditions for clouds seem to be preferred heading into Sunday. Dense fog currently at KUIN seems to be more isolated per webcams but this should become more widespread and established heading back into night. TES && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Dense Fog Advisory until noon CST Sunday for Audrain MO-Boone MO- Callaway MO-Cole MO-Knox MO-Lewis MO-Marion MO-Moniteau MO- Monroe MO-Pike MO-Ralls MO-Shelby MO. IL...Dense Fog Advisory until noon CST Sunday for Adams IL-Brown IL- Pike IL. && $$ WFO LSX