916 FXUS63 KILX 292327 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 527 PM CST Sun Dec 29 2019 .SYNOPSIS... Issued at 210 PM CST Sun Dec 29 2019 A cold front will push into Illinois this evening and combine with an upper-level disturbance to bring another round of rain to central and southeast Illinois tonight. The rain may briefly turn to snow across west central Illinois before precipitation ends after midnight. Cooler and more seasonable temperatures can be expected Monday and Tuesday before beginning to warm up again for the new year. && .SHORT TERM...(This evening through Monday) ISSUED AT 210 PM CST Sun Dec 29 2019 A jet streak rotating through the main upper-level trough currently located over the lower Missouri River Valley. The enhanced lift will combine with low-level forcing as a front moves across Illinois overnight bringing another round of pcpn to the area. GFS 700-600 mb frontogenesis ramps up late this afternoon and then moves on into the Great Lakes after 06z. This superimposition should lead to a relatively short but at times intense precipitation with most areas receiving another half to three-quarters of an inch of liquid. There may be a transition to snow over west central Illinois before ending as cold air advects into Illinois behind the front. The ground is quite warm from the above normal temps the past few days so any accumulation would be light. As the thermal trough moves across the state on Monday there is some potential for the development of a few snow showers, but at this time it appears the best instability will be over northern Illinois. Will include a chance across the north, but any accumulations should be light and short-lived. 850 mb temps plummet overnight bringing a shot of reality and reminding us of what winter is normally like in the Midwest. Seasonal highs in the mid 30s to lower 40s can be expected possibly ending our run of 10 days or so of above normal temperatures. .LONG TERM...(Monday night through Sunday) ISSUED AT 210 PM CST Sun Dec 29 2019 Dry weather is expected from Tuesday through at least Thursday morning as the next trough digs into the west coast and then lifts up toward the Midwest. Overall, models are pretty consistent initially phasing the energy which develops the best lift to our southeast. This forecast evolution also enables strong warm advection ahead of the trough returning our daytime highs to 10-20 degrees above normal. After the initial wave, models begin to diverge markedly with the strength of the system, which of course impacts the amount of cold advection behind it, and how much precip (and what form it will take) when the next wave moves through Thursday Night. GFS only slowly advects the trough eastward into the weekend keeping a chance light precipitation over the forecast area through Saturday. ECMWF is much more progressive. Will have to monitor the model evolution as we move through the week to get a better handle on what we will expect next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 524 PM CST Sun Dec 29 2019 A cold front is situated just west of the terminals early this evening and is progged to shift east across central Illinois with south winds veering to the west/southwest behind the front. Rain with a few showers/possible embedded thunderstorms will overspread the region in advance of the front early this evening with MVFR ceilings becoming more prevailing over the next couple hours and likely prevailing through the day Monday. Behind the front, winds will become quite gusty, with gusts picking up to around 30 kt much of the day Monday. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Barker SHORT TERM...Barker LONG TERM...Barker AVIATION...Deubelbeiss