Hardscrabble Snow Report

703 FXUS63 KLSX 090808 AFDLSX Area Forecast Discussion National Weather Service St Louis MO 208 AM CST Mon Nov 9 2026 .KEY MESSAGES... - Above average temperatures will persist into Wednesday before colder temperatures arrive during the second half of the week. - There is a 40 to 60 percent chance of showers, perhaps a thunderstorm or two, mainly along/east of the Mississippi River on Wednesday. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 206 AM CST Mon Nov 9 2026 The Mid-Mississippi River Valley will be positioned beneath west- northwesterly upper-level flow through Tuesday. A shortwave trough within this flow will shunt the low-level ridge currently in place eastward and force a weak cold front into the CWA tonight that stalls thereafter. Weak forcing and limited moisture return will preclude precipitation and even much in the way of cloud cover from forming along the front. Accompanying these dry conditions, southwesterly to westerly low-level flow and weak WAA will support well-above average temperatures through Tuesday, including highs in the mid-60s to low-70s F. Radiational cooling is expected to be relatively efficient again tonight with a loose surface pressure gradient near the front and little cloud cover. These conditions could promote additional patchy river valley fog, but slightly warmer temperatures will be less favorable for contributions from steam fog formation processes. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 206 AM CST Mon Nov 9 2026 A potent Alberta Clipper including an amplifying upper-level shortwave trough will traverse the Mid-Mississippi River Valley on Wednesday, facilitating the passage of a cold front through the CWA trailing a deepening surface cyclone across the Midwest. As is commonly the case with Alberta Clippers, the majority of associated precipitation will be to the north of the surface cyclone`s track and north of the CWA, but 40 to 60 percent of ensemble model membership has scattered showers developing along/east of the Mississippi River as moisture and forcing increase along the cold front. There are still some timing differences, however, that will influence how far west these showers develop. Steepening lapse rates with mid-level cooling may sufficiently compensate for modest moisture return to enable a few thunderstorms to develop as deterministic model guidance projects a narrow corridor of 500 to 1000 J/kg of MUCAPE. Additionally, a tightening surface pressure gradient will result in occasional wind gusts of 20 to 28 kt on Wednesday. Behind the cold front and initial shortwave trough, longwave troughing will amplify across the eastern CONUS with deep cyclonic flow ensuing over the Mid-Mississippi River Valley. As multiple additional shortwave troughs and/or vorticity maxima rotate around the parent longwave trough, the pattern appears favorable for periodic light showers or drizzle through Friday. With uncertain timing of each feature and a common dry bias in longer-rage model guidance in these patterns, the forecast is currently dry after Wednesday. Strong and persistent low-level CAA and increased cloud cover will at least result in coldest temperatures we have seen so far this season including highs in the 40s to low 50s F and lows in the mid-20s to mid-30s F. Confidence is high in Friday being the coldest day of the period with high temperatures falling to warm out of the 40s F, followed by a nearby surface anticyclone favoring widespread low temperatures in the 20s F if clouds clear enough. Next weekend, global model guidance agrees that mid-level heights will begin rising and the anticyclone will shift to the east of the region as downstream longwave troughing progresses eastward. This pattern change will lead to a warming trend but there are significant disparities on how quickly this process takes place, which determine how quickly temperatures will warm. Accordingly, the NBM interquartile temperature range inflates to 15 F by next Sunday, although even the 25th percentile still demonstrates an underlying warming trend. && .AVIATION /06Z TAFS THROUGH 12Z TUESDAY/... Issued at 945 PM CST Sun Nov 8 2026 Latest guidance isn`t as bullish on fog tonight. While there may be less widespread 2-5 mile fog overall, still think IFR steam fog with visibilities at or below 1SM is likely near bodies of water before sunrise on Monday. Any fog that develops should dissipate by 14-15Z. Elsewhere and otherwise, VFR flight conditions and light winds are expected outside of the fog tonight. There may be fog again on Monday night, and will continue to evaluate that possibility in subsequent forecasts. && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ SHORT TERM...Pfahler LONG TERM...Pfahler AVIATION...Carney