textproduct: Central Illinois

KEY MESSAGES

- Scattered showers and thunderstorms are expected today, mainly from I-72 south where pockets of heavy rains of 2-3 inches are possible and could lead to localized flooding especially if they occur in urban areas. - There is marginal risk of severe storms this afternoon from Taylorville to Paris south, primarily for damaging winds.

- Highs in the low to mid 80s this weekend, mid to upper 80s Monday and in the upper 80s and lower 90s Tuesday through Thursday. Afternoon heat indices peak in the mid 90s to near 100 during mid week.

DISCUSSION

Issued at 345 AM CDT Sat Jul 11 2026

Short Term (Today through Monday):

A weakening MCV over central IL was producing showers and isolated thunderstorms se of the IL river and from I-74 south. Thunderstorms with some heavy rains were over northern Christian county, nw and ne of Taylorville and tracking eastward. There were some flood warnings in northeast Coles, sw Edgar and northern Clark counties where MRMS shows pockets of 2-3.5 inches of rain past 6 hours. PWATs of 1.7-2.2 inches over CWA with 2 inches PW values as far north as Lincoln in Logan county. A surface boundary was near or just south of I-72. Aloft a weak 583 decameter 500 mb low was along the eastern IA/MO border. This feature to pivot into southeast IL by mid afternoon helping push the frontal boundary southward through southeast IL during this afternoon. An unstable tropical airmass lingers over central and southeast IL much of today, though some drier air moving into northern/nw CWA later this afternoon. MUCAPES peak from 1000-1800 j/kg se of the IL river this afternoon while effective bulk shear values of 25-35 kts in southeast IL shift further south during this morning. SPC Day1 outlook has marginal risk of severe storms south of a Taylorville to Paris line this afternoon/early evening for mainly damaging winds a risk from wet microbursts. The slight risk is over southern IL, south of CWA this afternoon/early evening where higher instability and wind shear, with MUCAPES near 2000 j/kg. PWATS are also higher the further south you go across IL today and a flood watch remain in effect south of CWA from Wayne, Edwards and Wabash counties south through this evening. HREF LPMM shows pockets of 2-3 inches of rain in less than 6 hours from I-72 south this afternoon and early evening. WPC Day1 ERO has marginal to slight risk of excessive rainfall se of the IL river today, with the slight risk in southeast IL. Also the RAP13 and NAM Nonsupercell Tornado parameters shows 1-3 units se of the IL river this afternoon, so funnel clouds may again be a risk like yesterday afternoon. A bit cooler today with highs in the lower 80s with some mid 80s nw of the IL river. Still muggy dewpoints in the low to mid 70s today se of the IL river and upper 60s nw of the IL river. Lows tonight in the low to mid 60s in central IL and upper 60s in southeast IL.

The weak cutoff 500 mb low moves into KY/TN on Sunday with best chances of convection shifting se of CWA. We still have slight chance of convection far se IL near Lawrence county Sunday afternoon. SPC Day2 outlook keeps marginal risk of severe storms se of IL along with WPC Day2 ERO. Highs Sunday in the low to mid 80s, warmest over the IL river valley. Dewpoints Sunday into Monday range from mid 60s northern CWA and lower 70s in southeast IL. A bit warmer highs in the mid to upper 80s Monday.

Long Term (Tuesday through Saturday):

Expansive mid/upper level ridge over the Rockies will lean into the western Great Lakes and build a 600 decameter 500 mb high over central MN on Monday. This strong 500 mb high to be just north and ne of central IL Tue/Wed bringing a heat wave to the area, though not quite as hot as last week. Highs in the mid to upper 80s Monday and upper 80s/lower 90s Tue-Thu with dewpoints back in the low to mid 70s. A Rex Block like pattern for much of upcoming work week with weak upper level low over TN river valley Monday, and over the southern MS river valley Tue/Wed. Much of central IL should be dry and very warm Mon- Wed, though upper level low in lower MS river valley may be close enough to produce isolated convection in southeast IL during Tue/Wed afternoon, though currently we keep pops less than 20%. Upper level ridge retrogrades westward back into the central Rockies on Fri/Sat with upper level trof digging over the eastern Great Lakes and Northeast States. This puts IL in a nw upper level flow with some signals of convection chances from Thu into Saturday, though chances are in the slight chance category.

The Climate Prediction Center (CPC) 8-14 Day Outlook for July 18-24 has temperatures and precipitation trending near normal over IL. CPC's Week 3-4 Outlook for Jul 25 to Aug 7 has equal chances of above or below normal temperatures and 35-45% chance of above normal precipitation (highest in eastern IL).

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1255 AM CDT Sat Jul 11 2026

MVFR conditions possible at times with showers and thunderstorms near I-72 next few hours as DEC is currently getting MVFR ceilings with showers. A frontal boundary near or just south of I-72 will push south toward I-70 by 12Z/7 am and linger near there Sat morning before pushing thru southeast IL during Sat afternoon. Have VCSH along I-72 into Sat morning while thunder chances appear further south closer to the front. Could still see MVFR conditions with showers if they occur into Sat morning along I-72. Latest CAMs show patches of low stratus clouds from I-72 south into mid Sat morning while fog is more limited in central IL. Clouds to scattered out from nw to se during Sat afternoon. NE winds 5-10 kts generally prevail next 24 hours.

ILX WATCHES/WARNINGS/ADVISORIES

None.