Peoria, Ill. (WMBD) — A powerful storm system will bring heavy rain, gusty winds and perhaps a little snow Central Illinois Wednesday night and Thursday. While not a winter storm, the storm system is likely to impact travel across Central Illinois, particularly on Thursday.
- Rain develops late Wednesday afternoon
- Periods of moderate to heavy rain Wednesday night
- Rain could mix with or change to snow west of the Illinois River Thursday morning
- Wind gusts of 40-60 mph expected Thursday
Rain & Snow: Timing, Intensity & Amounts
Rain is expected to develop south of I-74 between 3 pm and 6 pm Wednesday and will gradually spread north across the remainder of the region through 9 pm. Periods of moderate to heavy rain along with a few rumbles of thunder will be possible between 9 pm and sunrise. Soil temperatures should be warm enough for much of this rain to soak into the ground, though a bit of runoff along with ponding on the roads should be expected during and immediately following the heaviest downpours.
A dry slot will punch over Central Illinois Thursday morning causing rain to end, particularly east of the Illinois River. Meanwhile, rain is likely to continue west of the Illinois River with temperatures dropping into the mid 30s by mid morning. This could be cold enough to support a change over to a sloppy wintry mix or wet snow for a few hours before precipitation ends early Thursday afternoon. Given the warm ground temperatures snow will struggle to accumulate on anything other than cooler and elevated surfaces. Where snow does stick, a clumpy half inch of snow will be possible. particularly in Knox and Henry Counties.
Rainfall amounts through noon Thursday will generally range from 0.75″ to 1.25″ across Central Illinois, heaviest along and west of the Illinois River.
Strong Winds Thursday
As the strengthening area of low pressure moves across the state, winds will gradually increase Wednesday night blowing from the east at 10-20 mph with a few gusts up to 30 mph possible. The strongest winds will arrive Thursday morning when the strong low pressure center moves north of the region and a rapid increase in air pressure takes place. During this time, sustained west-southwest winds of 20-40 mph with gusts of 40-60 mph are expected across Central Illinois with the strongest winds east of the Illinois River where the dry slot could allow stronger winds aloft to mix down to the surface.
The National Weather Service has issued a High Wind Watch for areas along and east of I-55 from Thursday morning through Thursday afternoon where the strongest winds are expected. These strong winds will result in an elevated blow over risk for high profile vehicles travelling along I-74 Thursday.
More Light Snow Thursday Night & Friday?
A weaker system is expected to sweep across Central Illinois on heels of the departing low bringing a chance of some additional light snow to the area, though confidence remains low. Depending on the track and strength of the system, some light accumulations will be possible on grassy and elevated surfaces through Friday morning.