DeWitt, IA Weather

This Hazardous Weather Outlook is for portions of north central Illinois: northwest Illinois: west central Illinois: east central Iowa: northeast Iowa: southeast Iowa and northeast Missouri.

Day one: TODAY AND TONIGHT

Isolated thunderstorms are possible today in far southeast Iowa and far northeast Missouri. There is also a slight chance of thunderstorms tonight across the entire outlook area. Strong to severe storms are not expected today and tonight.

Days two through seven: SATURDAY THROUGH THURSDAY

The probability for widespread hazardous weather is low.

Spotter information statement

Spotter activation will not be needed today or tonight.

Key messages

- Rain chances return today (peaking at 60-90% coverage tonight) and linger into Halloween morning. Isolated thunderstorms are possible today and tonight.

- An active weather pattern early next week will bring rain and breezy conditions to the region, including on Election Day.

Short term

Issued at 103 AM CDT Fri Oct 30 2026

A cloudy and potentially rainy day for much of the area as a warm front over central Missouri lifts northward. Isentropic upglide on the 295-305 K layer along with WAA around 850 mb will support scattered showers (30-50% coverage) and isolated thunderstorms this morning. By the early afternoon, these showers and storms try to move northeastward but dry air in the low levels is expected to limit coverage (10-20%) north of Highway 30. No severe weather is expected, but mostly cloudy skies will keep highs cooler in the mid-50s to low 60s.

After a brief dry period for much of the area, the warm front finally advances northward this evening into our CWA, prompting another round of more widespread showers (60-90% coverage) and isolated storms. Again, no severe weather is expected with this round with the only hazards being periods of heavy rain and a few rumbles of thunder. With dew points climbing back into the mid-40s and low 50s, lows can only drop to those temperatures.

Heading into Halloween, the mid-level remnants of Tropical Depression Vance reaches the Central Plains and Mid-Mississippi River Valley, keeping scattered showers (30-60% coverage) around through midday. Continued cloud cover will cooler highs again in the upper 50s to mid-60s. Once the subtropical trough passes Saturday night, shortwave ridging sets in for Sunday. Rainfall totals of 0.25-0.75 of an inch are likely (60-80% chance) through Saturday.

Long term

Issued at 103 AM CDT Fri Oct 30 2026

A mostly dry Sunday is in the cards with highs climbing into 60s areawide, but some may call this the calm before the storm. Moving into Sunday night, a longwave trough over the western CONUS propagates into the Rockies, deepening low pressure along the Front Range of Colorado and Wyoming. As this mid- latitude cyclone moves into the Central Plains, it will begin to turn to the northeast, but disagreements among the global ensembles still exist on rather the system tracks through the Dakotas/Minnesota or through Iowa. This will have major implications on the location of the warm sector, our rainfall potential, and even severe weather chances. Latest LREF guidance has PWATs across the CWA climbing near or above 1.5 inches (50-70% chance), close to the maximum of climatological values for the first week of November! Regardless of track though, PoPs start to increase on Monday afternoon and stick around into Wednesday night. General consensus among the ensembles favor a cold frontal passage between Tuesday night into Wednesday with northwesterly flow pumping in some cooler, more seasonable air for the end of next week.

Overall, there is great uncertainty in rainfall totals with this system. The latest LREF guidance shows a 1-inch spread between the 25th and 75th percentiles with the 01z NBM having a 60-80% chance of 1+ inches of rainfall through Wednesday morning. One thing is more certain: the winds. Prior to the cold frontal passage, southerly wind gusts of 20-30 mph are likely (70-90% chance) Monday afternoon into Wednesday. Gusts after Wednesday will be dependent on the track of the low pressure. Regardless of solution though, a more active pattern compared the last few weeks is in store.

Aviation

Issued at 551 AM CDT Fri Oct 30 2026

An initial disturbance moving through the flow this morning is producing showers and isolated thunderstorms as it moves northeastward this morning across eastern Iowa. Entered a tempo group for potential MVFR visibilities in rain showers at KBRL with prob 30 groups at KMLI and KCID this morning for potential rain showers and MVFR visibilities. Ceilings this morning are expected to be between 5000 to 10000 ft. Ceilings are forecast to gradually lower through the TAF period. Winds will remain easterly at 5 to 10 knots through the period.

Another disturbance is forecast to overspread the area after 03 UTC Saturday and bring another round of showers to eastern Iowa TAF sites with periods of MVFR conditions through the end of the period. Thunderstorms are possible but the exact timing and locations are uncertain at this time so left them out of the TAFs for this issuance.

Watches, warnings and advisories

IA: None. IL: None. MO: None.