An area of low pressure is beginning to develop in the lee of the Rockies early this morning. The low will rapidly intensify today and race to the northeast, reaching the eastern Great Lakes by Monday morning. This track is expected to take the low directly through central Illinois tonight.
Showers and a few thunderstorms are possible today as the system approaches. However, the bulk of the rainfall, which may be heavy at times, is expected to occur tonight as the showers and storms become more widespread. Current indications suggest that rainfall totals of an inch to an inch and a half will be common by the time the system departs early Monday.
In addition to the heavy rainfall threat, some of the thunderstorms may become severe tonight south of a line from Jacksonville, to Lincoln, to Hoopeston. The highest threat is expect to occur south of the I-70 corridor. Large hail and damaging winds are the primary severe weather threat.
Hydrometeorological Prediction Center Day 1 Precipitation Forecast:
Storm Prediction Center Day 1 Convective Outlook: