Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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074 FXUS63 KILX 172017 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 217 PM CST Mon Nov 17 2025 .KEY MESSAGES... - Rain will spread west to east across the area this evening into tonight, with a few showers lingering through tomorrow. Most locations will see rain amounts between a tenth and half an inch. - Marginal risk (level 1 of 5) for severe weather for areas along and south of I-72 (east of Springfield) tomorrow. Main hazard will be large hail with elevated storms, but there is a 2% tornado risk in the southeastern IL counties. - The next opportunity for beneficial rainfall and strong storms arrives Thursday into Friday. There is a 30-60% chance (highest south) for rain amounts greater than 1 inch. && .DISCUSSION... Issued at 217 PM CST Mon Nov 17 2025 The rain system is moving into Western IL this afternoon. Looks like there could be some virga ongoing across IL this afternoon. The showers will start to move into the area from the west-southwest just after 00z this evening, progressing eastward. There is the potential for some rumbles of thunder through the overnight hours, but nothing severe. Most of the forecast area should be dry by 18z tomorrow, but there is the potential for redevelopment starting at 18z. This redevelopment will bring the risk for severe weather. We could see up to half an inch of rain from this system, with higher amounts locally with any stronger thunderstorms. The SPC has introduced a marginal risk (level 1 of 5) for severe weather for areas along and south of I-72 (east of Springfield). There is 2% tornado risk for for our southeast six counties (south of I-70), and a 5% hail risk for the entire outlooked area. It looks like, based off the HREF, the best MUCAPE values can be found tomorrow afternoon in southeastern IL (1000-1500 J/kg), with 0-6 km shear values of 70-75 knots. LCLs are pretty low tomorrow as well. There may be a small cap that the parcels would have to bust through, as many forecast soundings are showing a stable layer in the lowest 1 km. Otherwise, these storms would be elevated, which is what is influencing the 5% hail risk. The freezing level is around 3km based off the forecast soundings. The further south you get, the higher the chance storms could be surface based, which would allow for the 2% tornado risk. Wednesday would be a brief break in the rain as there is a lull between systems. Early Thursday morning, another low pressure system will pass through central and southeastern IL, bringing additional showers and thunderstorms. The temperatures should remain above freezing, keeping the precipitation type liquid. This system is looking to pack more of a punch with the rainfall amounts. From Thursday morning to Saturday morning, QPF of 1-1.5 inches is in the forecast. A warm front may lift up into southeastern IL with this low pressure system, which could bring some strong storms. Reading the SPC discussion for Day 4 (Thursday), they are hinting at the need for severe probabilities that day, but still too uncertain to put anything out yet. Temperatures stay near or just above normal for the next week. The warmest day this week is Thursday with highs in the 60s and lows in the upper 40s to low 50s , thanks to the warm front that will lift northward. Behind the low pressure system Friday, temperatures will drop back down to near normal. Copple && .AVIATION... (For the 18z TAFs through 18z Tuesday Afternoon) Issued at 1127 AM CST Mon Nov 17 2025 VFR conditions are expected to linger until a system moves in from the west, bringing precipitation into the forecast area. Rain is expected to begin in western sites by 02z, eventually pushing into CMI by 05z this evening. Visibility could be limited to 5SM at times of heavier precipitation. By 10-12z tomorrow morning, MVFR ceilings should enter all sites for the remainder of the TAF period. There is a chance for IFR ceilings later in the morning, but confidence is low in the occurrence, so left out for the meantime. All sites should be out of the rain by mid-morning. There is LLWS for about an hour or two for SPI and DEC in the morning by 10z/11z. 35 knots out of the south. Copple && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$