textproduct: Central Illinois

KEY MESSAGES

- There is higher confidence in scattered rain showers and isolated thunderstorms Friday morning from I-74 north. Rainfall amounts should be light.

- Dry fuels and low relative humidity will continue to provide an elevated risk for afternoon agricultural field fires through Saturday, especially southeast of the IL river.

- The remnants of Isaias will approach southeastern Illinois Saturday night, bringing rain chances over east central and southeast Illinois Saturday night through Sunday. Latest LREF has lowered and shifted southeast the probabilities for a half inch of rainfall, with a 30 to 50 percent chance for more than a half inch of rain southeast of a line from Flora to Terre Haute. A 20 percent chance over half inch rain exists as far northwest as Effingham to Danville.

DISCUSSION

Issued at 236 PM CDT Thu Oct 8 2026

Near Term (Tonight and Friday night)... High pressure and clear skies late this afternoon and evening will give way to a band of warm air advection clouds and rain showers later tonight and Friday morning. A 25-35KT 850MB low level jet will fuel the surge of warmer air and increase low level moisture content. In light of that and better CAM model guidance, there is increased confidence that some measurable rain will occur in our northern counties, primarily north of a line from Canton to Bloomington in the time frame from 7 am to Noon. Rainfall amounts could reach as high as a quarter inch in localized areas where pockets of instability trigger enhanced updrafts and a few rumbles of thunder. The wave will exit quickly to the northeast with rain chances ending in our forecast area around 1 PM CDT. Southerly winds will develop in concert with this WAA regime, helping push high temps into the lower to middle 80s, 10-15 degrees above normal.

Saturday through Sunday night... The remnants of Isaias will approach southeast Illinois Saturday night, with it's closest point of approach to Illinois late Sunday morning into early afternoon. The latest hurricane track guidance has a similar path to the overnight updates, with the central low pressure missing Illinois to the southeast. A surge of tropical moisture will precede the center of the low, with rain showers surging as far north as Taylorville to Paris Saturday evening. We continued 60-70 PoPs south of I-70 Saturday night into early Sunday morning, with rain shifting east of Illinois by early Sunday afternoon. Rainfall amounts have come down a bit, with up to a half inch in the forecast for mainly Lawrence County, and up to a tenth of an inch only up to I-70. A few hundredths are scattered up to eastern McLean and south to Christian County. Cloud cover and periodic showers will keep highs primarily in the 70s for our forecast area on Sunday. The remnants of Isaias will quickly depart to the east Sunday night, allowing high pressure to return to the area.

Extended Period (Monday through Thursday)... Monday will feature a quick surge of warm air ahead of the next cold front, as highs top out near record highs in the mid to upper 80s. The cold front is projected to push through central Illinois on Tuesday morning, bringing isolated showers to the area through the day. The post frontal airmass will remain conducive for rainfall with 30-50 pct PoPs expanding from across the area north of I-70 through Wednesday. A warm front arriving from the west on Thursday morning will keep those rain chances in the forecast Wed night and Thursday.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 655 PM CDT Thu Oct 8 2026

VFR conditions will prevail at all TAF sites next 24hrs. High cirrus will prevail through the night. A weak boundary will drop into central IL and bring possible showers to PIA and BMI during the morning. By afternoon they will be gone. Cigs will be mid clouds around 10kft only. SPI, DEC, CMI will see scattered clouds around 15-20kft but then just cirrus in the afternoon. PIA and BMI clouds will be mid clouds around 15kft in the afternoon. Light and variable winds through the night and then southeast winds less than 10kts tomorrow and then more southerly in the afternoon.

ILX WATCHES/WARNINGS/ADVISORIES

None.