270 FXUS63 KILX 071114 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 514 AM CST Sun Nov 7 2021 .SYNOPSIS... Issued at 155 AM CDT Sun Nov 7 2021 Mostly clear skies and mild temperatures will continue for today and Monday. Southwest winds will be gusty at times, especially during the afternoon hours. && .SHORT TERM...(Today and tonight) ISSUED AT 155 AM CDT Sun Nov 7 2021 Early morning surface analysis indicated high pressure stretched from the lower Mississippi Valley northeast through the Ohio Valley, while unorganized low pressure was in the lee of the Rockies. This resulted in light south winds keeping temperatures several degrees warmer than 24 hours ago in the mid 30s to lower 40s. Aloft, 500 mb map showed ridging expanding east from the Plains into the Upper Midwest. The stretch of excellent fall weather continues in the short term as upper ridging expands east today. MSLP gradient tightens with the high shifting farther east and a low pressure trof tracking into the Plains and Upper Midwest. So breezier southwest winds expected which could gust over 20 mph west of I-55 this afternoon. The stronger low level warm advection may be offset a bit by increased high clouds, but should still be sufficient to see widespread mid 60s highs. The gradient will keep the boundary layer mixed overnight for milder lows in the mid 40s west of I-55, while lighter winds in SE IL and associated decoupling to drop lows in the upper 30s. .LONG TERM...(Monday through Saturday) ISSUED AT 155 AM CDT Sun Nov 7 2021 Positive 500 mb height anomaly bullseye shifts overhead as the upper ridge leans across the region on Monday. Southwest gradient flow continues and will contribute to highs in the mid/upper 60s, or 10-15 degrees above normal. A low amplitude shortwave pushes a cold front into the area on Tuesday. The column appears pretty dry due to expansive high pressure north of the Gulf coast, and the better forcing is shown to our north. This should mainly cause an increase in clouds and a few sprinkles or brief light showers, and only have slight chance pops. Highs only a couple degrees cooler than Monday from the increased clouds. A much stronger system will develop over the Plains on Wednesday when a 140 kt upper jet punches east from the Pacific into the Rockies. 500 mb shortwave is forecast to close off over the upper Midwest Wednesday into Wednesday night, eventually sending a cold front through the region late Wednesday into Thursday. Due to the stronger forcing and better moisture return, a widespread rainfall should be seen. Better instability remains to our south so no thunder mentioned, but this could change with the dynamic nature of the system. Global ensembles are in good agreement that the large upper low will be centered near the Great Lakes on Friday, bringing deep layer northwest flow and cold advection to the Midwest. In fact negative 500 mb height anomalies are centered over the state Fri/Sat. Steep low level lapse rates could combine with waves embedded in the northwest flow to produce scattered showers. But the bigger story will be the return of well below normal temperatures and breezy conditions. GEFS mean 850 mb temps drop as low as -7C late Friday, and the blended guidance drops highs to the mid 40s Friday and lower 40s Saturday. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) Issued at 514 AM CST Sun Nov 7 2021 VFR conditions will continue for another 24 hours as high pressure remains in control of the sensible weather. Winds will be the main concern to aviation, with wind gusts this afternoon climbing into the 15-20KT range from the S-SW. Winds will generally diminish below 10kt this evening. However, a 40-45KT southwesterly low level jet will advance into IL from the west overnight, producing LLWS conditions at the terminal sites. The target height looks to be around 1200FT AGL. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...25 SHORT TERM...25 LONG TERM...25 AVIATION...Shimon