810 FXUS63 KILX 291615 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 1015 AM CST Sun Dec 29 2019 .SYNOPSIS... Issued at 256 AM CST Sun Dec 29 2019 Low pressure will slowly move across the upper mississippi valley over the next few days bringing periodic periods of clouds and gusty winds. One more widespread rain event is expected late this afternoon and tonight. The cloudy and more seasonable temperatures can be expected through the remainder of the year. && .UPDATE... Issued at 1015 AM CST Sun Dec 29 2019 Central and southeast Illinois are now fully in the dry slot between the initial trough in Indiana and the wrap-around moisture well to our west. A jet streak rotating through the main upper trough will combine with an incoming cold front to provide another round of precipitation late this afternoon and evening. This trend is handled well in current package and only minor tweeks to PoP based on current trends have been made. && .SHORT TERM...(Today and tonight) ISSUED AT 256 AM CST Sun Dec 29 2019 Impressive warm conveyor belt from western Gulf of Mexico combined with lift ahead of a deep closed upper low over the Plains has produced widespread rainfall across the area overnight. Temperatures have slowly risen into the upper 50s and lower 60s (25+ degrees above normal highs), while southeast winds have gusted to 25-35 mph. The rain will shut off from the west early this morning, as the dry slot overspreads the area. Much of the day will be dominated by mostly cloudy skies and continued south flow, pushing highs into the 60s. This will be near record highs for many areas (see climate section below). By later this afternoon and evening rain will overspread the area from the south, ahead of a strong shortwave and cold front. Forecast soundings show enough instability for isolated thunder mention over the eastern half of the CWA. Higher QPF from this round will focus east of I-55 with over a half inch, and up to one inch near the Indiana border. As the dry slot punches in from the southwest after midnight, the precip will taper off. This is expected before the column cools below freezing, so no snow is forecast. Depending on the timing of the front and better cold advection and resulting temperatures at midnight, record warm lows for the 29th are possible. .LONG TERM...(Monday through Saturday) ISSUED AT 256 AM CST Sun Dec 29 2019 The deep closed low is forecast to slowly spin across the Great Lakes Monday and Tuesday, keeping cold advection and brisk west winds in place. This will push temperatures down to seasonable levels for the first time since mid Dec. The main forecast challenge will be timing any stronger shortwaves rotating through the cyclonic flow. Latest models suggest Monday night to be favored for forcing on the southern edge of one of these waves, bringing light snow to the northern half of the CWA. A dusting to half inch of accumulation looks possible. As the upper low moves out, mid level flow turns zonal through mid-week, allowing for dry weather and a gradual warming trend. This should get temperatures back above normal on Wednesday, and 10-15 degrees above normal through the end of the week. A southern stream wave lifting northeast from the lower MS Valley into the eastern Great Lakes Thursday into Friday will be our next weather maker. With warm temperatures in place, currently appears this will be all rain. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) Issued at 515 AM CST Sun Dec 29 2019 Band of steady rain will continue shifting east, exiting KCMI around 13z. Ceilings have already risen to VFR levels, and expect this to be the trend through later this afternoon though patches of MVFR ceilings are shown by some short range models. Another disturbance lifting up from the south will cause more rain to overspread the area beginning late this afternoon or evening and persisting until 06-10z. This will be accompanied by MVFR ceilings and possibly a period of IFR ceilings late tonight at KDEC/KCMI. South winds gusting up to 20 kt will be common today. A cold front tracking east this evening will veer winds to the southwest. As the gradient tightens late tonight in response to low pressure deepening over the Great Lakes, 25 kt gusts will be common. && .CLIMATE... Issued at 256 AM CST Sun Dec 29 2019 December 29 Record Highs - all in 1984: Springfield.....65 Peoria..........65 Lincoln.........72 Normal..........67 Urbana..........62 Decatur.........65 Jacksonville....73 Galesburg.......64 Charleston......65 Danville........64 Effingham.......68 Olney...........66 December 29 Record Warm Lows: Springfield.....49 in 1884 Peoria..........45 in 1884 Lincoln.........58 in 1984 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barker SYNOPSIS...25 SHORT TERM...25 LONG TERM...25 AVIATION...25 CLIMATE...25