textproduct: Central Illinois

KEY MESSAGES

- A stretch of warm summerlike weather that started today is expected to last through Saturday. Expect daily highs in the upper 70s and lower 80s, with mid 80s likely Tuesday and Friday. Gusty south to southwest winds, occasionally reaching 30-45 mph into mid evening, and gusts of 20-35 mph during the work week, will accompany this warm period. Blowing dust may reduce visibility wherever early field work is taking place across the region until the fields are dampened by showers. - This week will be riddled with thunderstorm potential. Tuesday and Wednesday currently exhibit the highest probability (15-30%) of severe weather from I-55 nw, along with another possible threat of strong to severe storms over central/se IL Friday night into Saturday as the main cold front comes through. - There is also a potential for substantial accumulative rainfall throughout the week, with our multi-model ensemble predicting a high (60-80%) chance of exceeding 1 inch north of I-70 through Saturday and medium (40-60%) chance of exceeding 2 inches north of I-72.

DISCUSSION

Issued at 245 PM CDT Sun Apr 12 2026

The 19Z/2 pm surface map has a 994 mb low pressure in north central MN with a warm front over central parts of WI and lower MI. A 1033 mb high pressure was off the southern New England Coast. Tight pressure gradient between the low and high pressure systems was giving pretty strong SSW to SW wind over IL with gusts 30-45 mph with the 40-45 mph wind gusts northwest of I-70 to near the IL river. Had a recent report of blowing dust in a farm field 4 miles nw of Nokomis near the Christian/Montgomery county line. A short wave near the KS/MO border had showers as far east as sw IL, just west/sw of CWA while heavier showers and isolated thunderstorms were in far nw IL into northeast Iowa and sw WI and tracking ne ahead of the short wave.

Short wave to eject ne into central/northern IL by 03Z/10 pm and into central/southern Lake MI by 06Z/1 am tonight. The latest CAMs have showers spreading quickly ne over central and northern IL during mid/late afternoon while se IL is more scattered this evening after supper. Could be an isolated thunderstorm with these showers but SPC does no have a severe risk of IL through Monday morning. Rainfall amounts generally fairly light between a tenth and quarter inch north of I-70 with highest amounts nw of the IL river where locally higher amounts around half inch possible. SSW to SW winds to stay breezy through Monday with gusts 35-45 mph north of I-70 through early evening and still gusting 25-35 mph after dark this evening. Blowing dust still a concern in recently tilled fields before showers dampen the ground. Mild lows tonight in the low to mid 60s, mildest in southeast IL. Breezy sw winds on Monday with gusts 25-30 mph gives warm highs in the lower 80s and more humid with dewpoints in the 60s.

We have slight chance of convection in southeast IL Mon morning, then a low chances of convection during mid to late Mon afternoon over CWA into Mon evening. Stronger forcing/low level jet occurs north of central IL during Mon night with marginal to slight risk of severe storms (slight risk far northern row of IL counties near the WI border). We have 20-30% chance of convection north of a Quincy to Bloomington line overnight Mon night with the 30% pops from Galesburg to Lacon north. Then 20-30% pops north of I-70 Tue morning (30% pops north of Lincoln).

SPC day3 outlook recent update continues slight risk of severe storms from Danville and Champaign to Springfield north/nw for late Tue afternoon/evening. They now introduced a level 1 of very large hail and stronger wind gusts nw of I-55 over IL river valley, so this area will need to be watched closely for more significant severe storms. Warm highs Tue in the low to mid 80s before the storms and moist dewpoints in the 60s with breezy sw winds gusting 25-35 mph.

SPC Day 4 outlook has 15% or greater risk of severe storms from McLean, Logan and Sangamon counties west for Wed afternoon/evening. We may see a brief break from severe wx risk Thu/Thu night before another chance of strong to possible severe storms Fri night and Sat as main cold front comes through. Heavy rains will also be a threat with thunderstorms this week. Much cooler air ushers in during 2nd half of weekend.

The Climate Prediction Center (CPC) 8-14 Day Outlook for Apr 19-25th has a 45-55% chance of above normal temperatures and 40-45% chance of above normal precipitation over central and southeast IL. So the mild and unsettled weather pattern looks to continue the next two weeks across IL.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 702 PM CDT Sun Apr 12 2026

A pair of low pressure systems will move across the northern Great Plains and Great Lakes keeping central Illinois in a moderately strong southerly gradient through the period. A wave of warm advection driven showers is lifting across central IL this evening, however, very dry low levels will keep precip amounts light and limit the chance for lower vsby. MVFR ceilings will become more widespread through the evening and are expected to persist into Monday afternoon. Meanwhile, winds will favor a 180-220 direction through the period and remain gusty (20-30kt) much of time, albeit more sporadically so overnight.

ILX WATCHES/WARNINGS/ADVISORIES

None.