Tan-Tar-A Snow Report

279 FXUS63 KEAX 140459 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 1159 PM CDT Tue Oct 13 2026 .KEY MESSAGES... - Strong/Severe thunderstorms expected during the evening/early overnight tonight. Initial hazards include large hail and damaging winds before evolving into a damaging wind threat. - Excessive rainfall also expected during the evening/overnight, with a Flood Watch encompassing the KC Metro and areas south/southeast of I-70. - Continued chances for precipitation during the day Wednesday and into Thursday. - Temperatures cool down Friday and Saturday, with increasing likelihood to meet frost/freeze criteria across northern MO (40-60%). && .DISCUSSION... Issued at 333 PM CDT Tue Oct 13 2026 The cold front from yesterday afternoon has slowly progressed southeastward, and has stalled out from Salina, KS northeastward to about Peoria, IL. South of this boundary, temperatures have climbed into the high 80s/low 90s, with dewpoints residing in the low 70s. This has increased instability along/south of the boundary to about 2000-2500 J/kg, with effective bulk shear residing around 35-40 kts. This unstable, sheared airmass will see influence from a shortwave and strengthening LLJ later into the evening, providing synoptic- scale lift and invigorating the development of organized thunderstorms. CAM guidance throughout the day has indicated an initial discrete mode with storms as they fire up along the boundary, before congealing into an MCS by the overnight period. More recent guidance has been varied with the exact trajectory of the MCS during the overnight period, but generally has placed it along/south of the I-70 corridor, following the boundary/CAPE gradient. With initial discrete storm modes, there is an associated hazard for large hail/damaging winds. There is an additional concern for isolated tornadoes, especially if storms develop near/along the boundary or within the proximity of the LLJ. After these initial discrete storm modes, damaging wind will become the primary hazard with the congealing MCS. An additional concern with storms overnight will be excessive heavy rainfall. PWATs of ~1.7 inches has developed across north-central MO throughout the day, with guidance indicating PWATs of up to 2 inches by the evening. Additionally, moisture transport resides just parallel/at a slight angle to the surface boundary, with a moist vertical profile in place. Although storms will remain progressive through the evening with strong cloud layer winds and upshear/downshear vectors, efficient storms training over the same locations will enhance concerns for flooding through the overnight, especially with dry antecedent conditions making it harder for soils to saturate right away. The current Flood Watch was expanded northward to include counties within the KC Metro area, as guidance has also increasingly trended towards higher rainfall accumulations during the overnight period (~2-4 inches in the HREF LPMM by early Wednesday). The severe threat is expected to diminish through the overnight as the environment becomes more capped and synoptic scale forcing diminishes. Continued moist advection over the boundary will keep light rain across the forecast area during the early morning, before it looks to also diminish by the afternoon as the boundary sags further south. CAMs have been varied with their resolutions of activity during the day tomorrow, with recent runs either placing additional scattered showers/storms across the area while others keep the forecast area dry for most of the day into the evening. Currently, PoPs for the day reside around 30-50% to account for the additional moist advection over the boundary. The primary corridor for continued severe hazards during the day tomorrow resides south of the boundary, which looks to remain just south of our forecast area. With uncertainty regarding the evolution of an ongoing flooding concern, have chosen not to extend the Flood Watch in time across the forecast area, with greater opportunities for excessive rainfall continuing to the south and west of the forecast area. By early Thursday, the upper-level trough over the Intermountain West will lift towards the Great Lakes, and continue precipitation chances through synoptic-scale ascent with dCVA and strong low-level WAA. There are indications of an excessive rainfall threat with this next round of precipitation, with HREF LPMMs coming in a bit hot in swaths of high accumulations during that timeframe (~1-3 inches). However, this threat looks to be relatively short-lived as the trough quickly lifts towards the Great Lakes by the evening. As this trough and its attendant surface low lift off towards the northeast, a cold front will sweep southeast across the forecast area and synoptic high-pressure will build in from the west. The cold frontal passage will help bring down temperatures to more seasonable temperatures, with high temperatures in the high 50s/low 60s during the daytime. Building high pressure behind the surface low will enhance the pressure gradient going into Friday, and lead to breezy conditions not too dissimilar from this past Monday (gusts up to 30- 35 mph possible). Building high pressure will also lead to synoptic- scale subsidence, keeping conditions dry going into the weekend. Enhanced radiational cooling under clear skies will allow temperatures to drop into the 30s overnight, putting areas of northern MO/northeastern KS under their first frost conditions since late March. As surface high pressure slides off towards the Ohio Valley and mid-level ridging builds in from the west, northerly winds will turn out of the south, prompting a warm up of high temperatures into the 70s throughout the weekend. Model guidance increasingly deviates in the synoptic pattern by the start of next week, leading to decreased confidence in the potential for precipitation by Monday. However, continued southerly flow and the positioning of the ridge axis over the central CONUS maintains thoughts that temperatures will continue to warm through the end of the forecast period. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1153 PM CDT Tue Oct 13 2026 Variable but generally MVFR conditions expected at the terminals through the end of the forecast period. Light rain showers will continue to move through portions of eastern Kansas and western Missouri for the next couple of hours before gradually dissipating before/around dawn. With a moist subcloud layer, BR seems likely before sunrise as well which may occasionally drop VIS to MVFR. CIGs are expected to fall to MVFR overnight as well with southern sites teetering around MVFR/IFR for much of the day. Heading into Wednesday evening, IFR CIGs look to become more prevalent. Otherwise, northerly/northeasterly winds. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch until 10 AM CDT Wednesday for MOZ028-029-037- 043>045-053-054. KS...Flood Watch until 10 AM CDT Wednesday for KSZ057-060-103>105. && $$ DISCUSSION...SPG AVIATION...Macko