Hardscrabble Snow Report

652 FXUS63 KLSX 310738 AFDLSX Area Forecast Discussion National Weather Service St Louis MO 238 AM CDT Fri Jul 31 2026 .KEY MESSAGES... - Showers and thunderstorms are expected today, with some severe storms possible during the afternoon and evening. Damaging winds will be the primary threat. - Much cooler air moves in behind a cold front this weekend, with temperatures gradually warming back closer to normal through the upcoming week. && .SHORT TERM /THROUGH SATURDAY/... Issued at 233 AM CDT Fri Jul 31 2026 High pressure which brought us the last few days of low summertime humidity is moving east into the Appalachians today. To our west, a shortwave trough is moving southeast out of the Northern Plains around the periphery of a western US ridge. This shortwave trough is rather potent for this time of year, and moist advection through the Plains ahead of the trough has led to the development of a convective complex currently entering northwest Missouri this morning. This is expected to continue east southeast over the next several hours, decreasing in intensity as it moves east potentially outrunning the advancing moisture and instability. However, we`re still likely to see it track through much of our area during the morning hours. Behind this convection, dewpoints rise 10 degrees or more in a SSW flow ahead of an approaching cold front. This greater moisture combined with daytime heating should lead to surface based instability in the 2-3000 range just as the cold front moves into our region this afternoon. Just how unstable it gets will depend on how quickly the morning clouds and rain move out and how much sun we get locally. But we do expect enough destabilization for another round of thunderstorms to develop this afternoon. With the potent mid level wave we`ve got seasonably strong wind shear available, enough to provide some organization to the storms that develop this afternoon. A mix of supercells and convective clusters is likely. With a warm and humid air mass, long skinny CAPE, and very high precipitable water values near 2 inches, heavy rain and damaging downburst winds will be the primary threats. Relatively quick storm motions should limit total rainfall amounts, but some localized areas where convective scale elements favor longer duration rainfall could see higher totals up to 3+ inches. There`s also enough low level shear and curvature in the wind fields to be alert for a few tornadoes as well. This may be with initial supercells or with QLCS clusters which align with the low level shear vectors. All of this convection gets swept southeastward with a cold front this evening, ending the threat locally and ushering in a cooler, drier air mass for Saturday. Although it will be drier in an absolute sense, with dewpoints falling back into the 60s after briefly rising into the 70s ahead of the front, we aren`t quite done with the rain just yet. The shortwave trough closes off into a closed low over Illinois with wrap around showers reaching back into Missouri. These should be relatively light with limited instability available, but the combination of clouds, showers, and cold advection will hold temperatures in the 70s for highs. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 233 AM CDT Fri Jul 31 2026 The lingering low will gradually move east on Sunday with surface high pressure arriving in its wake. We`ll gradually start to see a warming trend as the August sun modifies the air mass and modest ridging replaces the departing trough. By midweek temperatures will be warming back up closer to normal, in the upper 80s to low 90s. Considering the position and trajectory of the incoming surface high, moisture return from the Gulf will be shut off through midweek. There`s some discrepancy in guidance on how high dewpoints get with a skewed distribution in ensemble guidance. Most raw model guidance is relatively modest in the 60s, while NBM is at the top of the available guidance in the low to mid 70s. This seems to be driven largely by the bias corrections in NBM. If these higher dewpoints do occur, then we could be looking at another period of 100+ heat index values developing. However, our confidence in this is lowered due to the surface high blocking moisture from the Gulf, limiting moisture increases locally to evapotranspiration and moisture pooling ahead of a potential front later in the week. It`s that next front in the Thursday-Friday time period that represents our next best chance for rainfall. && .AVIATION /00Z TAFS THROUGH 06Z SATURDAY/... Issued at 1032 PM CDT Thu Jul 30 2026 A few very weak showers are blossoming across central Missouri at this hour, but are causing no impacts at regional terminals. Meanwhile across southeastern Nebraska, a slowly-weakening line of strong to severe thunderstorms is approaching northwest Missouri. This feature will continue its southeastward march overnight, arriving at the central Missouri terminals around 12Z where an isolated thunderstorm threat will exist. The line will decay further as it moves closer to the St. Louis metropolitan area, which will likely preclude a thunderstorm threat by the time it arrives. After a few hours of dry and VFR conditions from late morning into the afternoon, a surface low and attendant upper-level wave will enter the region and ignite additional thunderstorms through the evening. A few may be capable of 40-50kt gusts, necessitating AMDs when there is greater certainty in terminal impacts. The surface low and upper-level wave will slow down and stall across the broader region, threatening lower CIGs at all terminals. The worst impacts are forecast at KUIN, where IFR conditions may develop. All other terminals will have at least some threat for MVFR to IFR conditions through sunrise Saturday, by which point conditions may gradually improve. && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ SHORT TERM...Kimble LONG TERM...Kimble AVIATION...MRB