072 FXUS63 KILX 050156 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 856 PM CDT Wed Apr 4 2018 .UPDATE... Issued at 856 PM CDT Wed Apr 4 2018 No significant updates needed this evening as light and variable winds develop with high pressure moving over the area and temperatures drop rapidly to the low and mid 20s over much of the area, upper 20s near I-70 and southward. High clouds already streaming over the area will thicken overnight to help limit the temperature drop which could otherwise be even more substantial. && .SHORT TERM...(This evening through Thursday) ISSUED AT 300 PM CDT Wed Apr 4 2018 High pressure will drift across the area tonight bringing another chilly night to central Illinois with most areas nudged below guidance due to the location of the surface ridge, light winds and at least starting out with a mostly clear sky. However, the next weather system will start to bring in some mid level cloud cover overnight with models suggesting the better lift and moisture will be north of I-74 on Thursday, thus the higher chance POPs are located mainly across the north half of the forecast area. Temperatures tonight will drop into the lower 20s over our northern counties with mid to upper 20s common over the remainder of the forecast area. Highs on Thursday should rebound nicely ahead of the upper wave and frontal system approaching our area as afternoon highs will be in the 40s north to mid to possibly upper 50s in our southwest counties. .LONG TERM...(Thursday night through Wednesday) ISSUED AT 300 PM CDT Wed Apr 4 2018 A cool and active weather pattern will hold over our area through this period with several low amplitude waves progressing east- southeast and then amplifying as they are forced southeast into the mean longwave trof position over Hudson Bay. This will bring at least 3 chances for precipitation to parts of our area during this period with the more significant southern wave forecast to shift east and interact with a frontal boundary south of the Ohio River Valley late Friday through Friday night. This will bring the threat for rain to start out with but thermal profiles suggest a change to snow Friday night with some light accumulations possible, 1-2 inches south towards I-70 with more like an inch or so further north. Once that wave shifts away from our area on Saturday, another chilly Canadian high will drift southeast into the Midwest bringing unseasonably cool weather to the forecast area. Lows Friday night will drop into the teens north to the upper 20s far southeast with highs on Saturday struggling through the 30s. As the large Canadian high drifts southeast across the area on Saturday, dry conditions should hold through Saturday evening before our next weather maker brings the threat for more rain and snow to the region on Sunday. The cool and damp weather regime will continue into next week with the system on Sunday and Monday followed by another storm system timed into our area by most models by late Wednesday or Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 625 PM CDT Wed Apr 4 2018 VFR conditions have developed across the central IL terminals this evening as high pressure moves in from the west. A weather disturbance will move into the area Thursday morning bringing a chance of light snow mainly along the I-74 sites, changing to a mix and eventually rain for Thursday afternoon. Conditions look to be primarily VFR, however local/brief MVFR cigs/vsby are possible. Winds WNW around 10-12 kts will diminish shortly after sunset, then increase to 10-12 kts with higher gusts from the S/SE late Thursday morning through Thursday afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...37 SHORT TERM...Smith LONG TERM...Smith AVIATION...37