708 FXUS63 KILX 271733 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 1133 AM CST Fri Dec 27 2019 .SYNOPSIS... Issued at 345 AM CST Fri Dec 27 2019 Cooler temperatures will prevail today across central and southeast Illinois in wake of a cold frontal passage with return of some sunshine during this afternoon. A storm system will pass to our northwest bringing occasional rain showers Saturday into Sunday, with a few thunderstorms possible Saturday afternoon and Saturday night. After a brief warm up this weekend with breezy southerly winds, much cooler temperatures are expected early next work week. && .UPDATE... Issued at 1112 AM CST Fri Dec 27 2019 Latest satellite imagery shows skies beginning to clear west of the Illinois River, while overcast conditions hold firm further east across the remainder of the KILX CWA. Models are not handling the cloud cover particularly well...with most solutions suggesting a rapid clearing trend this afternoon. Given only very light NW flow and low late December sun angle, think this is unrealistic. Have updated the forecast to feature partly to mostly sunny skies along/west of the Illinois River this afternoon, with partial clearing reaching as far east as I-55. Further east, think cloudy skies will prevail along and east of I-57 through the entire afternoon. High temperatures will mainly be in the lower to middle 40s. && .SHORT TERM...(Today and tonight) ISSUED AT 345 AM CST Fri Dec 27 2019 A cold front was in far southeast IL early this morning and will push se to along the Ohio river by late morning and into central KY by sunset. 1024 mb high pressure over nw MO will drift east across central and northern IL by late afternoon as it strengthens a bit to 1026 mb. Broken to overcast low stratus clouds (bases 500-1500 ft) will decrease from the nw during the afternoon, though mid/high clouds will continue streaming up from the sw thru the day. So a mostly cloudy day overall with more sunshine possible this afternoon especially further nw you go. Much cooler today (after highs in the 60s past 2 days), with highs mostly in the 40s over central IL and lower 50s se of I-70. High pressure strengthens to 1028 mb as it expands over the eastern Ohio river valley and mid Atlantic States by dawn Saturday. Clouds increase tonight, and the latest model suite continues to trend slower with arrival of qpf into central IL overnight, and much of area appears to stay dry thru 3 am, then have 20-30% chance of light rain from Peoria to Taylorville west between 3-6 am overnight. Lows tonight in the mid to upper 30s in central IL and lowers 40s along highway 50 in southeast IL. .LONG TERM...(Saturday through Thursday) ISSUED AT 345 AM CST Fri Dec 27 2019 A strong 546 dm 500 mb low low was near the southern CA/AZ and Mexican border early this morning while a strong upper level ridge over the southeast States with 588 dm 500 mb high near the Bahamas. IL was in a sw upper level flow which will bring an unsettled weather pattern to the area this weekend, after a fairly long stretch of dry weather. Models eject upper level low to near the CO/KS border by sunset Sat and associated surface low of 999 mb emerges over eastern KS. Models bring rain showers ne over central IL during Saturday, though not quite was wet initially over the area on Sat. Eastern and Southeast IL appear to stay dry thru Sat morning, then chances of rain showers there during Sat afternoon. Have slight chance of thunderstorms spreading ne over area Sat afternoon and continues Sat night, and in eastern IL early Sunday morning. Milder highs Sat in the upper 50s, with lower 60s in southeast IL with breezy se winds. Highest rain chances are Sat night along with heaviest qpf as low pressure deepens to 990-995 mb by dawn Sunday as it lifts toward southern MN. Mild lows Sat night in the low to mid 50s with strong southerly winds gusting 25-35 mph. A dry slot works into central and nw IL Sunday morning while high rain chances continue east of I-57 on Sunday with breezy sw winds. Highs Sunday in the upper 50s western CWA and lower 60s central and eastern IL with mid 60s by the Wabash river. Though temps will likely be slipping during the afternoon with passage of a cold front. Good chance of rain showers Sunday evening, then becoming more widely scattered overnight Sunday night with chance of light snow showers too especially northern CWA as colder air arrives. Deep upper level low pivots over the upper MS river valley and western Great Lakes early next week though most models keep qpf north of CWA from Mon afternoon thru Tue. Lows Sunday night in the lower 30s in central IL and mid 30s in se IL. Much colder highs Mon in the upper 30s in central IL and lower 40s southeast IL with strong WSW winds gusting 25-30 mph. Clouds on Monday to give way to partly sunny skies during Tue but continued brisk west winds to keep it seasonably cool. Lows Mon night in the mid to upper 20s. Highs Tue in the upper 30s central IL and around 40F in se IL. Weak surface high pressure ridge settles over the mid and southern MS river valley on Wed bringing partly to mostly sunny skies and lighter winds to area then. Highs Wed in the low to mid 40s. A southern stream storm system to eject into the southern MS river valley on Thu and spread chances of mixed precipitation ne into central and southern IL late Wed night or Thursday, though mainly light rain chances in southeast IL. Most of Wed night now appears dry as models have trended slower with bringing pcpn ne into the area. Highs Thu and Fri remain in the low to mid 40s with lows in the lower 30s. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1133 AM CST Fri Dec 27 2019 IFR/MVFR ceilings prevail at the central Illinois terminals late this morning: however, a slow west-to-east clearing trend will take place this afternoon. Based on satellite trends, have scattered ceilings at KPIA by 20z...then further east to KBMI/KSPI by 22z. Further east, think ceilings will rise to low VFR at KDEC/KCMI by early this evening. The partial clearing will be short-lived however, as a developing warm front will spread low clouds back into the area late tonight into Saturday morning. Forecast soundings suggest MVFR returning at all sites by 10z/11z. Winds will be NW at around 5kt this afternoon, then will become light/variable this evening as high pressure moves overhead. Once the high departs, gusty E/SE winds will develop Saturday morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barnes SYNOPSIS...07 SHORT TERM...07 LONG TERM...07 AVIATION...Barnes