929 FXUS63 KILX 101105 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 605 AM CDT Wed Oct 10 2018 .SHORT TERM...(Today and tonight) ISSUED AT 337 AM CDT Wed Oct 10 2018 An upper level ridge just off the east coast expected to slowly erode as the trough and associated frontal systems slowly progress eastward. Some movement of the front and associated rain expected today as showers and thunderstorms move across Central IL. The developing surface low associated with the trough over the western half of the country is expected to lift out of the Missouri River Valley and into the Great Lakes today. The cold front will be at the western border of the state by midday. As the system lifts through, precip along and ahead of the boundary will receive an assist in vertical motion from the low, as well as additional deep bulk shear from 50-60kts briefly. Effective SRH is limited however, and instability should be relatively weak as potential for insolation is limited. Either way, in marginal risk for severe weather today as the system moves through the region, with the best chances between noon and 6pm or so until the front clears the state. Better instability will line up with the timing of the afternoon east of I-55. NAMNest/HRRR inconsistent with handling storms, but hint at some quick pulse-type storms scattered across a broader area. Models clear out the precip in time to drop temperatures overnight/Thursday morning into the 40s, a good 20 degrees cooler than the prev night. .LONG TERM...(Thursday through Tuesday) ISSUED AT 337 AM CDT Wed Oct 10 2018 Cooler air moves into the region with a pattern shift aloft to a more zonal flow. Overnight low temperatures dropping into the 30s Thursday morning and Friday morning, with frost possible in the northern half of the state. A cutoff low in the deep western trough will retrograde slightly off the Baja peninsula. ECMWF/GFS still bringing the next wave through the Midwest for Friday, although now the ECMWF is far more aggressive with QPF over a broader area. GFS is a little more conservative and focused on the southern half of the state. Considering this time frame will also likely see impact from the remnants of Michael off of the Atlantic coast, and another storm brewing over the Baja peninsula...confidence in details is low. Pops return to the forecast for Saturday night in the GFS...delaying to Sunday in the ECMWF...and dominate the remainder of the weekend. This system moves out of the SW and into the Ohio River Valley, looking far different than 24 hrs ago. This time around, the low moving through the Ohio River valley puts Central Il on the northern edge of the system, picking up more in the way of stratiform with little thunder threat to wrap up the weekend. Either way, much cooler air in place will drop Sat and Sun morning lows into the upper 30s/lower 40s. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 601 AM CDT Wed Oct 10 2018 Deteriorating conditions this morning as scattered showers spread across Central IL in advance of a cold front. Gusty southerly winds throughout the morning, and cigs dropping...though a lot of variability in the observations and satellite imagery at the moment from low MVFR to clear. Thunderstorm threat spreads along and just ahead of a cold front from west to east around midday through 00z. Winds coming around to more westerly behind the boundary and maintain gusts through the overnight. Forecast may be a bit optimistic in clearing the cigs behind the front tonight, depending on how much llvl moisture materializes from showers through the day. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HJS LONG TERM...HJS AVIATION...HJS