595 FXUS63 KILX 160901 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 401 AM CDT Thu Aug 16 2018 .SHORT TERM...(Today and tonight) ISSUED AT 355 AM CDT Thu Aug 16 2018 Issued a dense fog advisory through 9 am cdt for the IL river valley, with the most widespread dense fog occurring nw of the IL river. Areas of fog will occur over central sections of CWA with locally dense fog possible into mid morning. While patchy fog in eastern IL, along and east of I-57, into mid morning where more cloud cover prevailing and limiting dense fog formation. Radar mosaic shows isolated showers east of I-57, while more widespread convection was east of IL over IN and KY, and tracking ENE. Latest CAM models continue to show isolated to scattered showers and perhaps a few thunderstorms over eastern IL during this morning. A 579 dm 500 mb low over south central NE will track into central/south central IA by 00Z/7 pm today and into central IL by overnight. This will spread scattered showers/thunderstorms into the IL river valley later today and over rest of CWA during this evening, and linger chances overnight with upper level low/trof moving into area. SPC day1 outlook has marginal risk of severe wet microbursts across CWA late this afternoon and evening. With moderate instability (CAPES rising above 2000 j/kg) by late afternoon/early evening and some wind shear of 30-40 kts developing by this evening. SPC has 5% risk of wind and hail, though the hail threat is sw of a Galesburg to Lincoln to Effingham line. Precipitable water values around 2 inches or higher today and evening could also cause locally heavy rain as well. Highs in the low to mid 80s today, coolest over east central IL. Lows tonight in the upper 60s over central IL and around 70F in southeast IL. && .LONG TERM...(Friday through Wednesday) ISSUED AT 355 AM CDT Thu Aug 16 2018 Upper level trof will linger over CWA on Friday and continue scattered convection through the day with highest pops in southeast IL where surface front moves into that part of the state Friday afternoon, with likely pops southeast of I-70. Highs in the lower 80s Friday, with mid 80s by Lawrenceville. Still humid on Friday with dewpoints in the lower 70s. Isolated to scattered convection to linger se of I-55 Friday evening, then dry conditions expected over area. Lows Fri night in the mid 60s central IL and upper 60s in southeast IL. Isolated showers/thunderstorms possible southeast of I-70 on Saturday afternoon closer to frontal boundary near the Ohio river. Otherwise a dry conditions expected over CWA this weekend with highs in the mid 80s Sat/Sun. A potent short wave/trof off the Pacific NW coast will track into the Midwest on Sunday night and into MO/IL during Monday. Still some differences with the 00Z forecast models with handling this wx system, as ECMWF is stronger and wetter with this storm system and if this verifies, could be some strong to severe thunderstorms Monday afternoon/evening. GFS model is weaker and slower with this feature and GEM is in between. Have chances of showers/thunderstorms arriving over western half of CWA overnight Sunday night with good chances of convection Monday and Monday evening across area, then diminishing overnight Monday night into Tue. Highs Monday in the lower 80s, then cooler highs in the upper 70s Tue/Wed, with Lawrenceville near 80F. Lows to drop into the mid to upper 50s by next Tue and Wed night. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1144 PM CDT Wed Aug 15 2018 Scattered showers will continue to affect mainly southeast Illinois the rest of the night. Isolated thunder, while possible, is unlikely again until tomorrow afternoon. Have removed all thunder up until 18z tomorrow. Instability params show thunder chances will return tomorrow afternoon, but still on the spotty side. Of particular concern tonight is the potential for some dense fog, especially along and west of the Illinois river. Areas of clearing in our western counties will set the stage for dense fog, especially for PIA, and possibly BMI. The latest runs of the high resolution guidance have diminished coverage of dense fog to mainly in our W-NW counties. SPI, DEC and CMI look to remain just east of the dense fog area, according to a consensus of the high resolution guidance. Have included VLIFR visibility for PIA and BMI from 10z to 13z, with LIFR cigs likely under that scenario. The fog and ceilings should improve by 14z, with MVFR ceilings probable for most of the day tomorrow, along with spotty showers and storms, especially in the afternoon. Winds look to remain light and variably through tomorrow evening, under a weak surface pressure gradient. && .ILX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM CDT this morning for ILZ027>031- 036-037-040-041-047-048. && $$ SHORT TERM...07 LONG TERM...07 AVIATION...Shimon