Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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562 FXUS63 KILX 311941 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 241 PM CDT Sun May 31 2026 .KEY MESSAGES... - Above normal temperatures are likely to persist into mid June, with highs generally in the 80s. Humidity values are expected to increase late this week into early next week. - Widely scattered showers and storms are possible through Monday, with the best chance (30-40%) being south of a Galesburg to Decatur to Lawrenceville line late tonight into Monday morning. Dry conditions are expected Tuesday through Thursday. && .DISCUSSION... Issued at 230 PM CDT Sun May 31 2026 Scattered showers affected areas from I-55 nw today, with isolated showers lingering north of I-74 and lifting northward as they continue to diminish. A small MCS was over east central MO south of St Louis and drifting ESE toward southern tip IL and this convection should pass south of CWA into this evening as it weakens too. Another disturbance/MCS to develop over southern Iowa/northern MO tonight and track se over southern half of IL late tonight into Mon morning. The highest chances of convection appears to be over southern IL, while 30-40% pops in our southern/sw counties and slight pops northern/ne CWA. SPC Day1 and Day2 outlook though Monday night keeps marginal risk sw of CWA where more unstable air mass in sw IL into MO and closer to frontal boundary south and sw of IL. Lows tonight in the lower 60s. The CAMs show much of convection passing se of CWA during midday and afternoon hours on Monday as skies become partly to mostly sunny Monday afternoon. Highs Monday in the lower 80s, with mid 80s over west central IL. The Omega Block will reposition itself a bit during mid week with large mid/upper level low over New England and mid Atlantic States and northern Rockies into southern CA while narrow upper level ridge from Texas into the upper MS river valley and Ontario Province Tue with upper level ridge shifting over IL on Wed. Large Canadian high pressure to settle southward from Hudson Bay into the Great Lakes on Tue, into the Ohio river valley Wed and mid/southern Atlantic States on Thu. Dry/fair wx expected over central/se IL Mon night through Thu night with a fair amount of sunshine Tue/Wed and partly to mostly sunny Thu. Highs Tue in the lower 80s, warm back into the mid/upper 80s Thu as SSW flow starts and also will increase humidity late this week. A summerlike pattern takes shape over IL late this week into early next week with warm and more humid conditions prevailing along with daily chances of showers and thunderstorms Friday through Monday/June 8th, starting in central IL Fri and in southeast IL too on Saturday. Climate Prediction Center (CPC) Day 8-14 Outlook for June 8-14 has 55-60% chance of above normal temperatures over central/se IL and 33-40% chance of above normal precipitation. CPC Risk of Hazardous Temperatures shows Slight Risk (20-40%) of Extreme Heat over IL from June 8-11th. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1250 PM CDT Sun May 31 2026 An area of scattered showers had impacted PIA and BMI airports at midday and should lift ne of these terminals next hour or so. VFR conditions still prevailed with these showers and generally expected VFR conditions to continue next 24 hours thru 18Z/1 pm Monday. Isolated showers may linger over central IL into tonight but coverage appears limited. Another cluster of showers and isolated thunderstorms tracking southeast out of MO and southern Iowa could impact central IL airports from 11-16Z Monday especially along I-72 and have prob30 groups for SHRA. If isolated thunderstorms occur may see possible brief MVFR conditions. ESE to SE winds 5-9 kts this afternoon to be around 5 kts tonight and ENE winds 5-10 kts Monday. && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ KEY MESSAGES...07 DISCUSSION...07 AVIATION...07