textproduct: Central Illinois

KEY MESSAGES

- Severe storms appear likely late Tuesday afternoon into Tuesday night. Storms will be capable of producing tornadoes, some of which could be strong (EF2 or higher), as well as large hail (2 inch or larger), damaging winds and isolated flash flooding. There is an Enhanced Risk (Level 3 of 5) of severe storms northwest of a Springfield to Hoopeston line, with a Slight Risk (level 2 of 5) to the south.

- A warming trend continues through Tuesday, with well-above normal temperatures in the 70s today, then near 80 degrees on Tuesday. Some locations could set record high temperatures.

- Total rainfall amounts from the mid-week system are favored to exceed an inch (40-70% chance), and localized amounts over 2 inches are possible (10-20% chance).

DISCUSSION

Issued at 230 PM CDT Mon Mar 9 2026

Peoria has at least tied their record high of 71F at 2 pm today.

Low stratus clouds lifting to stratocumulus clouds (bases of 1-2.5k ft) have lifted as far north nw as I-55. The cloud bases are slowly lifting and also scattered out on northern/nw fringe. A few updates were done to increase cloud cover in areas from I-55 east this afternoon. Some of these low clouds to linger in eastern IL tonight, and likely expand in coverage late tonight into Tue morning with some fog also possible near warm front close to northern CWA. A few CAM members also show isolated showers and even possible thunder tonight over part of central/eastern CWA east of IL river after dark with sw low level jet increasing moisture into the area. SPC day1 update has general risk of thunderstorms tonight east of I-55. Mild lows tonight mostly in the upper 50s/lower 60s. Unseasonably warm highs Tue of 75 to 80F and near record highs expected again.

Earlier model runs had kept warm front northern IL but latest CAM runs have trended further south with frontal boundary and dropping as far south as I-74 during Tue afternoon. This frontal boundary will be a key player for severe storm/supercell development during mid/late Tue afternoon into Tue evening. Effective SRH of 150-300 m2/s2 along with MLCAPES of 1500-2000 j/kg along and south of this boundary to support supercells with tornadoes (5-10% risk of strong tornadoes EF2 or stronger north of I-70 with highest risk from I-72 north), 15-30% risk of large hail north of I-70 with very large hail 2 inch or larger north of a Shelbyville to Paris line. Also 15% or greater risk of damaging winds. The 2nd round of severe storm risk is later Tue evening and overnight further south of rest of central/se IL for mainly damaging winds and large hail though tornadoes still pose a threat. Training could set up during Tue night especially later Tue evening into WEd morning and could lead to moderate to heavy rains, with most areas likely seeing 1 inch more and a few spots locally up to 2 inches. WPC day2 excessive rainfall outlook has marginal to slight risk Tue night north of I-70 with the slight risk from I-72 north.

Cold front forecast to push se toward the IL river around 12Z/7 am Wed morning and into southeast IL by 18z/1 pm. SPC day3 outlook has marginal risk of severe storms (damaging winds/hail) in far southeast CWA se of a Robinson to Olney line Wed morning, with a better risk of severe storms Wed further southeast. Similar to this past Saturday, will likely see temps fall behind the cold front during Wed with temps in the low to mid 40s over central IL by supper time Wed and upper 40s/lower 50s in southeast IL. Breezy sw winds ahead of the front to become breezy nw behind the front with gusts of 25-35 mph.

1030 mb high pressure moving into the central and southern plains Wed night to decrease clouds from nw to se during Wed night along with diminishing winds as cold air arrives. Subfreezing lows Wed night in upper 20s to around 30F central IL and lower 30s in southeast IL. Surface ridge to shift se of IL by Thu afternoon with increasing sw breezes over the IL river valley during Thu afternoon as clouds increase too. Highs Thu in the upper 40s to around 50F.

A fairly strong northern stream short wave and low pressure system to track ESE into the Northern Plains Thu afternoon and into northern lower MI by midday Friday. Brunt of its precipitation to pass north of central IL though we have 20-30% chance of light rain showers central and northern CWA, highest pops from I-74 north. Dry conditions expected Fri through Saturday with temps modifying into the upper 50s and lower 60s Sat (mid 60s south of I-70 and sw of Springfield on Saturday). Another strong low pressure system takes a further south track into the Midwest on Sat night night and Sunday likely bringing showers later Sat night and Sunday. A cold front moving se over IL on Sunday to return colder air and could have chance of light snow showers too late Sunday and Sunday night with minor snow accumulations possible. Cold weather early next work week with highs next Monday only in the mid to upper 30s and lows in the 20s Sunday night and upper teens/lower 20s next Monday night.

07

AVIATION

(For the 00z TAFs through 00z Tuesday Evening) Issued at 637 PM CDT Mon Mar 9 2026

VFR conditions will prevail at all sites this evening, but the scattered clouds over CMI, DEC will come back and become broken again at CMI with cigs below 3kft. Morning hours at CMI could see IFR cigs. CMI, PIA, BMI will be close to the warm front, so lower cigs below 1kft will be possible during the morning hours. Then as the sun gets higher, cigs will begin to rise, but still be below 2k or 3kft at all sites. DEC and SPI will see cigs rise into VFR category, but PIA, BMI, and CMI will remain MVFR through the afternoon. Storms are expected to develop near the sites tomorrow afternoon, so have PROB30 groups at all sites for the late afternoon hours. Winds will be south too southwest through the period with steady winds of 10-15kts with gusts tomorrow of 20-23kts.

Auten

CLIMATE

Issued at 1249 PM CDT Sun Mar 8 2026

Record high temperatures for Monday and Tuesday:

Location Monday Tuesday ======== ========= ========= Bloomington 73 (1974) 78 (1893) Champaign 73 (1925) 73 (1990) Charleston 79 (1925) 79 (1990) Decatur 78 (1925) 79 (1990) Lincoln 78 (2000) 78 (1955) Olney 81 (1925) 80 (1990) Peoria 71 (1918, 2021) 77 (1955) Springfield 75 (1918, 1925) 80 (1955)

Geelhart

ILX WATCHES/WARNINGS/ADVISORIES

None.