765 FXUS63 KILX 091941 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 241 PM CDT Tue Oct 9 2018 .SHORT TERM...(This evening through Wednesday) ISSUED AT 240 PM CDT Tue Oct 9 2018 Low pressure currently centered over Kansas will track northeastward along a frontal zone from northern TX through Iowa to northern Michigan tonight through Wednesday. As the low tracks into Wisconsin the trailing cold front will get a strong push eastward into central IL. Convection associated with warm advection ahead of the front will be the focus for thunderstorm activity tonight, which may be severe given up to 40 kts of sfc-6km bulk shear and up to several hundred J/kg CAPE lingering late in the night. As such, SPC continues a marginal risk of severe thunderstorms, mainly for a locally damaging wind threat, into areas from the Illinois River westward into tonight. Models have not significantly changed the timing of the front, with the front reaching the Mississippi shortly after sunrise, Illinois River just after noon, and Indiana around sunset. The character of convection has changed, however, as 12z convective-allowing models now show multiple clusters of convection ahead of the front in warm air advection overnight, followed by convection becoming more closely tied to the front by Wednesday afternoon as the front accelerates eastward into eastern Illinois. 1000 J/KG CAPE look possible, along with 40-50 kt bulk shear, implying a continued risk for severe thunderstorms Wednesday afternoon as the front progresses east across Illinois. Temperatures will be mild ahead of the front, then begin to cool after frontal passage. Lows tonight should be in the upper 60s, followed by low to mid 70s from the Illinois River westward, but reaching upper 70s to low 80s to the east. && .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 240 PM CDT Tue Oct 9 2018 Following Wednesdays cold front, the east coast ridge moves off to the east with a longwave trough beginning to establish over the central and eastern U.S. The resulting westerly flow pattern for central IL should result in much cooler weather for several days. Highs 50s are expected Thursday through Tuesday, with a few upper 40s even possible in the northwest. Lows are generally in the 40s with some potential mid to upper 30s mainly Thursday and Friday nights. A shortwave Friday could result in rain showers Friday afternoon or evening. The only additional precipitation in the next week looks to be as a disturbance from remnants of Pacific Hurricane Sergio that eject across the southern Rockies and move into the Ohio Valley region over the weekend. Precipitation amounts this far north still look to be modest with instability weak enough that no lightning would be expected. Since the large scale pattern between now and next weekend goes through a large transition, predictability remains low and these latest features remain subject to change. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1252 PM CDT Tue Oct 9 2018 Isolated TSRA expected this afternoon across the central IL terminal area, with less likelihood toward the east. Have included VCTS in all TAFs through the afternoon except KCMI. Have included tempo TSRA at KBMI 18-20Z as a developing thunderstorm appears headed for that terminal. Aside from isolated thunderstorms, VFR conditions look to be predominant until late in the period. After sunset, most terminals should see a decrease in thunderstorm activity until later in the night when clusters of thunderstorms will likely develop and potentially affect the terminals through 18Z. Winds S 10-15 kts with gusts to around 20 kts today, then gusts decreasing after 00Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...37 LONG TERM...37 AVIATION...37