Hidden Valley Ski Area snow report

234 FXUS63 KLSX 170327 AFDLSX Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 1027 PM CDT Sat May 16 2026 .KEY MESSAGES... - Additional scattered thunderstorms are possible (20-30%) this afternoon and evening. The main risk is large hail and damaging winds. - Additional thunderstorm chances return early this week with a more widespread severe weather threat possible along a slow moving cold front Monday night into Tuesday. && .SHORT TERM... (Through Late Sunday Night) Issued at 112 PM CDT Sat May 16 2026 An upper level trough has moved onshore over the western CONUS, with a surface low over the Central High Plains and a warm front extending into Iowa. There was a secondary warm front/convergence zone draped along the I-70 corridor this morning, and this is what kicked off this morning`s storms. These storms have reinforced a baroclinic zone across the CWA, with temps in the upper 60s across our north and pushing 80 in our south. As we move through the afternoon and into the evening, additional thunderstorm development will be largely focused to the north and west of the area, near the primary warm front. However, the above baroclinic zone may serve as a secondary focus for convection this afternoon, and a few of the most recent runs of the HRRR are hinting at that possibility. Given the weak forcing along this feature and lack of deep forcing, I don`t expect widespread convection, but a few additional thunderstorms remain a possibility. If these storms do develop, MUCAPE around 2,500 J/kg and effective bulk shear around 30 kts may allow few of these storms to become strong enough the support large hail or damaging winds. The stronger convection expected to develop near NW MO should grow upscale and track to the ENE through the night. While previous runs of high-res guidance has largely kept these storms to our north, a few of the CAMs have begun pushing them a bit further south into our area. These storms may also pose a marginal threat for damaging winds and large hail as they diminish and move across NE MO and west-central IL this evening. Tomorrow, longwave troughing will amplify over the western CONUS, reinforcing deep southwesterly flow over the Mid-Mississippi Valley. Given the lack of any focused forcing for ascent, it appears likely that we`ll see little to no precipitation and notably less cloud coverage than today. The increased insolation, coupled with the above deep southerly flow, should push temperatures quite a bit higher tomorrow. BSH && .LONG TERM... (Monday through Next Saturday) Issued at 112 PM CDT Sat May 16 2026 A compact shortwave will eject from the western CONUS trough on Monday, spurring cyclogenesis over the Central Plains. The resultant forcing for ascent from central KS through Iowa and into the Great Lakes will force another round of thunderstorms, largely to the north and west of our forecast area. These areas will also feature strong dynamics, which coupled with a very unstable airmass, will result in scattered/numerous strong to severe thunderstorms. The atmosphere will also be rather unstable over the Mid-Mississippi Valley, but without any focused forcing, anything more than widely scattered thunderstorms appear unlikely. Additionally, much more modest wind shear on our CWA will limit storm organization and severe potential. Our best chance for severe weather through Tuesday morning will be tied to whether the storms that develop to our northwest are able to grow upscale and persist as they advance into our forecast area. A cold front associated with Monday`s surface low is expected to push through the region on Tuesday. Ahead of the front, instability should build into the 1000-2000 J/kg range, which coupled with the front, will result in the best chance for thunderstorms in the extended forecast. While the SPC convective outlook continues to highlight our area on Tuesday, I do see a couple of factors that may limit the potential for severe thunderstorms. First of all, the best deep layer dynamics are expected to remain well to the north of our forecast area, limiting deep layer shear to around 30kts ahead of the front. Secondly, it`s unclear how storms from Monday night and Tuesday morning will unfold across the area and whether the atmosphere can recover before the frontal passage. Even if we do recover, the above wind shear would be only marginally supportive for severe thunderstorms. With that, the 15% contour from SPC seems appropriate, but I would not expect that to increase much, barring a notable change in the models. The above cold front should push the deep moisture our of our region, with the vast majority of guidance keeping dewpoints below 60 through the end of the week. Persistent weak zonal flow aloft may open the door for a few weak shortwaves to move through the region, but the lack of moisture will keep precipitation chances limited. BSH && .AVIATION... (For the 06z TAFs through 06z Sunday Night) Issued at 1022 PM CDT Sat May 16 2026 VFR conditions are expected at I-70 corridor terminals through the 06Z TAF period. However, showers and likely a few thunderstorms will continue to impact UIN over the next few hours, including the first hour or two of the 06Z TAF period. Lightning, bursts of heavy rain (with visibility reductions), and occasional gusty winds are the most likely hazards with this activity. Afterward, VFR conditions are likely to develop here as well and persist through the end of he period. Breezy south winds will develop by mid to late morning tomorrow and persist through the end of the period. Another round of showers and thunderstorms will likely move through the area just beyond the end of the period Monday morning, but this is not yet within the 06Z TAF window. BRC && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX