198 FXUS63 KLSX 190923 AFDLSX Area Forecast Discussion National Weather Service Saint Louis MO 423 AM CDT Sun Apr 19 2020 .SHORT TERM... (Through Late Monday Afternoon) Issued at 418 AM CDT Sun Apr 19 2020 Latest radar mosaic is showing showers moving into the far southern CWA with scattered showers or sprinkles farther north near I-70. This is occurring in an area of moisture convergence associated with the low level jet. The RAP shows this area of showers moving off to the east by mid morning as the low level jet veers to the east. The chance for showers will persist into the afternoon as a cold front currently over Iowa will move southeast across Missouri and Illinois. It it be aided by some weak lift from a shortwave trough that will move across the area this afternoon. Dry weather is expected tonight into Monday morning before the GFS/NAM is showing another weak shortwave trough moving across the area. Will maintain low chance PoPs for showers on Monday. Highs today will be similar to yesterday as lows this morning are relatively warm, so highs will climb into the 60s ahead of the front. The airmass behind this front is not particularly cold, so lows tonight will only fall into the mid 30s-lower 40s. Winds will shift out of the southwest by afternoon on Monday allowing for highs to climb back into the 60s. Britt .LONG TERM... (Monday Night through Saturday) Issued at 418 AM CDT Sun Apr 19 2020 Showers will move out of the area on Monday evening as the trough moves east of the area. Then dry weather is expected overnight Monday and Tuesday as subsidence sets in behind the trough and a surface high moves across Missouri and Illinois. Then the GEFS/EPS mean remain consistent in showing a southern stream upper trough and attendant surface low moving across the area Wednesday night into Thursday. Will keep likely/categorical PoPs for showers and thunderstorms going with this system. There will be a short lull in the rain late week before the next trough will moves quickly into the Midwest on Friday and Saturday bringing the next chance for showers and thunderstorms late Friday into Saturday. Temperatures will be cooler on Tuesday behind a cold front that will move across the area early in the day. Temperatures will climb slightly on Wednesday and Thursday as warmer air is drawn north ahead of the storm system, but they will be tempered somewhat by clouds and rain. Temperatures will warm up again late in the week ahead of next weekend's storm system. This is reflected well in the EPS mean plumes and the 850mb temperatures. Britt && .AVIATION... (For the 06z TAFs through 06z Sunday Night) Issued at 1035 PM CDT Sat Apr 18 2020 A couple of features may bring minor aviation impacts to the region on Sunday. The first of these features is a low pressure system to our southwest. This low will track well south of the region during the day on Sunday, but will help advect some low level moisture into the region. Simultaneously, a cold front will sweep through the region from the northwest, causing winds to swing around to the northwest. The low will very likely bring rain and MVFR cigs to the southern half of the area, with chances decreasing to the north. I doubt UIN will see much rain or any cigs below 3,000 ft. The other terminals will likely be very near the northern edge of the most widespread precip and MVFR cigs. Most guidance keeps cigs just above 3,000 ft at all terminals, save for the typically reliable GLAMP. Confidence in this aspect of the forecast is somewhat low, so for now, I've introduced SCT025 to hint at the chance for MVFR cigs in the late morning and early afternoon. Likewise, confidence on precip coverage is not very high near the terminals, so have stuck with VCSH in the TAFs. BSH && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX