903 FXUS63 KILX 240438 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 1138 PM CDT Thu Jun 23 2022 .SYNOPSIS... Issued at 231 PM CDT Thu Jun 23 2022 Clear and cool conditions will be observed across central Illinois tonight with low temperatures dropping into the lower to middle 60s. Highs on Friday will top out in the upper 80s to around 90 degrees with an increase in cloud cover noted during the afternoon. && .UPDATE... Issued at 830 PM CDT Thu Jun 23 2022 Aside from some adjustments to evening cloud cover due to thicker cirrus cloud cover in southern portions of the forecast area, streaming off of an MCS over the Plains, no significant updates are needed this evening. High pressure over the area continues to shift eastward, although continuing to provide the dominant subsident influence on our weather. Winds, turning from northerly to southeasterly overnight, should be quite light, and skies clear enough, that temperatures will fall to lower to mid 60s again tonight. && .SHORT TERM...(This evening through Friday) ISSUED AT 231 PM CDT Thu Jun 23 2022 High pressure will continue to control the weather across central Illinois for the next 24 hours. Clear skies and light winds under the ridge axis will lead to excellent radiational cooling conditions tonight, resulting in overnight lows dropping into the lower to middle 60s. The high will begin to shift further eastward on Friday: however, other than perhaps an isolated afternoon thunderstorm west of the Illinois River, conditions will remain warm and dry with highs once again reaching the upper 80s to around 90 degrees. .LONG TERM...(Friday night through Thursday) ISSUED AT 231 PM CDT Thu Jun 23 2022 A vigorous upper low noted on latest water vapor imagery over southern British Columbia will track eastward along the U.S./Canadian border...then dig into the Great Lakes by early next week. As this feature approaches the Northern Plains, a 50-60kt nocturnal 850mb jet will develop ahead of the associated surface cold front Friday night. Based on model consensus, it appears a cluster of thunderstorms will develop along the nose of the jet across eastern Nebraska/western Iowa...then will track eastward into far northern Illinois/Wisconsin by Saturday morning. While much of this activity will likely remain north of central Illinois, scattered storms may develop further south along a warm frontal boundary lifting into the area. As a result, will include chance PoPs for thunder along/west of I-55 late Friday night into Saturday morning. Return moisture on the back side of the slowly retreating high will be minimal by that point, resulting in meager instability. Therefore think areal coverage/intensity of any convection will be limited. Once any morning thunderstorms dissipate, Saturday afternoon appears to be hot and dry as the atmosphere becomes strongly capped via a 12-13C warm layer at 700mb. Once the cold front pushes across the Mississippi River into west-central Illinois Saturday evening, the cap will weaken sufficiently to produce scattered thunderstorms. Given SBCAPEs likely in excess of 3000J/kg but 0-6km bulk shear of only 20-25kt, think severe weather potential will remain low. Latest SPC Day 3 Convective Outlook highlights areas west of the Illinois River with a Marginal Risk, and this seems reasonable given initial instability parameters. Instability will wane further east and later into the night as the front pushes into central Illinois. Will carry high chance to likely PoPs across the board Saturday night, but think severe chances east of the Illinois River will be slim to none. The cold front will exit the KILX CWA by around midday Sunday, with a few showers/storms possibly lingering into Sunday afternoon along/south of I-70. Once the front departs, a period of cool/dry weather will prevail early next week before temperatures moderate by next Wed/Thu. The coolest conditions will occur on Monday when afternoon highs only reach the upper 70s/lower 80s and lows Monday night dip into the middle to upper 50s. After that, temps will climb back to summertime readings in the lower 90s by Thursday. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1138 PM CDT Thu Jun 23 2022 VFR conditions expected through the 06z TAF period. Cloud cover generally thin high clouds, with a few diurnal cumulus around 5000 ft AGL after 16Z. Winds light and variable overnight, becoming S to SE 5-8 kts after 16Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...37 SYNOPSIS...Barnes SHORT TERM...Barnes LONG TERM...Barnes AVIATION...37