FXUS63 KLSX 151812 AFDLSX Area Forecast Discussion National Weather Service St Louis MO 112 PM CDT Thu Oct 15 2026 .KEY MESSAGES... - A few strong/severe thunderstorms remain possible in southwest Illinois from early to mid afternoon, with damaging wind gusts and a brief tornado possible. For other areas, the threat of severe storms is low. - A strong cold front will bring blustery northwest winds an a sharp cooldown overnight. Below average temperatures are expected through Saturday, with morning frost increasingly likely Saturday and Sunday mornings. - A steady warmup is expected Sunday onward. && .SHORT TERM /THROUGH FRIDAY/... Issued at 106 PM CDT Thu Oct 15 2026 The focus of the short term period continues to be on the potential for showers and thunderstorms early this afternoon, followed by the passage of a fall-like cold front this evening and overnight. The latter will bring blustery northwest winds and a sharp cooldown, and it will feel a lot more like you'd expect for mid-October (or even later). As of early afternoon, a surface low was located across north- central Missouri, with a warm front extending east-southeastward into southwest Illinois, and a sharp cold front approaching the Kansas City metro area. Meanwhile, a pre-frontal trough was also noted across east-central and southeast Missouri, with locally enhanced surface convergence along it. This pre-frontal trough has been the focus for convection through the morning, and as of this writing weak and largely elevated thunderstorms have moved across the Mississippi River and into southwest Illinois. Ahead of these storms and the pre-frontal trough, deeper moisture, slightly enhanced instability (~1000J/kg MLCAPE), and backed (albeit weak) surface winds have developed. While cloud cover is still abundant, there has been at least some clearing, and this environment appears to be the most favorable area for strengthening storms over the next few hours. Wind shear is a bit weaker here than further west, where stronger mid/upper level flow exists, but there is just enough to support a low-topped supercell and a brief tornado or two, mostly likely before 3 PM as most of this activity should move east of the area by then. Overall though, confidence is not high that storms will become severe until after they exit the area. West of the pre-frontal trough, while bulk wind shear is a bit higher, veered surface winds and meager instability (in spite of more ample clearing), and a lack of redevelopment in high-resolution model guidance do not strongly suggest that more storms are likely upstream any later in the afternoon. While we likely will see some warm air advection showers, and also a few showers along the advancing cold front, but the probability of strong or severe storms in this area is low. Late this evening, the previously mentioned cold front will surge through the region, bringing strong cold air advection and blustery surface winds. While we don't expect Advisory-level wind speeds, gusts to 30-35 mph will be well within reason, particularly during the day tomorrow as mixing increases. Meanwhile, temperatures will drop quickly, with morning lows dipping into the 40s in most areas before warming only slightly into the 50s during the day thanks to the persistent cold air advection. After reaching the 90s just two days ago, temperatures Friday will be approximately 15 degrees below average. Brisk winds will persist through the day, and weaken in the evening and overnight, allowing for efficient cooling and low temperatures dropping into the low 40s to mid 30s Saturday morning. A few protected river valleys may even flirt with the freezing mark as well, especially in northeast Missouri and the Ozarks, and it's increasingly likely that these wind-protected areas will see some frost Saturday morning. In fact, NBM probabilities for minimum temperatures of 32 degrees or less increase to nearly 50% in northeast Missouri, and chances are likely similar in Ozark river valleys where small-scale cool air drainage contribute additional cooling. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Issued at 106 PM CDT Thu Oct 15 2026 From Saturday onward, a slow, steady warming trend is expected to develop as an upper level ridge moves overhead, and south- southwesterly low level flow becomes re-established. Surface high pressure and a dry-continental airmass should also keep precipitation chances minimal. After a very chilly morning Saturday, temperatures are likely to rebound only into the low 60s, with a slight increase from the day before thanks largely to clear skies. Overnight, another very chilly night is expected, as surface winds will remain very light and radiative cooling is expected to be quite efficient. Current deterministic forecasts suggest that morning lows in the mid to upper 30s should be common area-wide, with another opportunity for a brief freeze in Ozark river valleys in particular thanks to cool-air drainage. Sunday morning should be the last opportunity for a freeze, although some patchy frost will be in play again Monday morning. From Sunday afternoon onward, southerly low level flow becomes firmly established, and temperatures will steadily warm each day through mid-week. Temperatures are expected to climb back to near average by Sunday afternoon, with high confidence (90+%) in above average temperatures Tuesday onward, and a reasonable chance to exceed 80 degrees (40-60%) Wednesday onward. Meanwhile, little additional precipitation is expected for the next week. && .AVIATION /18Z TAFS THROUGH 00Z SATURDAY/... Issued at 100 PM CDT Thu Oct 15 2026 Thunderstorm chances are decreasing at all local terminals, and now attention turns to low ceilings and a sharp cold front with gusty northwest winds. Some improvement to VFR ceilings is expected for a few hours at all terminals this afternoon with the possible exception of UIN. However, ceilings are expected to dip back to MVFR and locally IFR levels along and behind a passing cold front this evening and overnight. Winds will also turn to the northwest and increase sharply, and remain elevated through the end of the period. Ceilings are expected to improve again briefly tomorrow morning, but MVFR low stratus will likely return near the end of the period. BRC && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ SHORT TERM...BRC LONG TERM...BRC AVIATION...BRC