Area Forecast Discussion

KEY MESSAGES

- There is a Slight, level 2 out of 5, risk of severe storms for much of the area Saturday afternoon and evening. Damaging wind and hail are the primary severe risks but an isolated tornado cannot be ruled out.

- If storms could repeat over the same areas Saturday afternoon and evening, a flash flood risk is possible due to wet soil conditions from recent heavy rainfall.

- More active weather is expected around the middle of next week when two separate storm systems are forecast to move through the Midwest.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 300 PM CDT Fri Jun 12 2026

Through Tonight:

A cooler and drier air mass in place will allow temperatures to fall into the 50s for lows tonight. Dry conditions will continue tonight into Saturday morning before the next wave of showers and storms arrives Saturday PM.

Saturday - Saturday Night:

An upper level disturbance moving out of the Plains may initiate storms during the morning to mid day time frame across portions of central Iowa. Some of the latest CAMs show the storms then growing upscale into one or more line segments and racing to the east-southeast, passing through the outlook area during the afternoon and evening hours.

SPC has maintained a Slight Risk (level 2 of 5) for severe storms approximately along and south of Highway 30, with a Marginal Risk (level 1 of 5) to the north. Mid-level lapse rates are progged to be quite steep (7.5-8 C/km) and thus supportive of large to very large hail (potentially greater than golf ball size). Additionally, moderate deep layer shear between 40-50 kts will aid storm organization with any bowing segments that develop posing a damaging wind risk. Exact timing remains a bit uncertain with the most widespread activity anticipated during the afternoon and evening hours.

Another concern would be the potential for heavy rain and localized flash flooding due to wet antecedent conditions. Repeated rounds of storms with PWATs near 1.75 - 2" are supportive of rainfall rates between 1-2"/hr. It appears the highest potential for a few rounds of storms and therefore localized flash flooding is in the counties along and south of Highway 34. WPC has a Slight Risk (level 2 of 4) for excessive rainfall along/south of Highway 30.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 300 PM CDT Fri Jun 12 2026

Sunday - Monday: Beautiful mid June weather is expected with highs only in the upper 60s to mid 70s along with low humidity! Forecast lows are in the upper 40s to mid 50s across the area.

Tuesday through Wednesday night Assessment...medium (40-60%) confidence on rain chances

All global models prog two separate systems moving through the Midwest around the middle of the week. The various solutions are putting more emphasis on the second, stronger system.

The first system is progged to move through the area Tuesday afternoon and night. However, there are questions regarding moisture availability for the first system.

Interestingly, the model trend has been to get slowly wetter with time. This may be in response to the Integrated Vapor Transport slowly getting stronger. The NBM has trended higher with PoPs, now showing 30-60% for later Tuesday/Tuesday night.

The better chances for rain look to be Wednesday/Wednesday night when the stronger clipper-type system moves through the Midwest. The high over the deep south has moved east allowing the Gulf to open up. A respectable LLJ develops helping to transport moisture north.

However, timing now comes into play regarding when the deeper moisture arrives for the system. That appears to be Wednesday night, which if correct, would indicate the better rain chances are east of the Mississippi. Indeed, the model consensus has the better rain chances east of the Mississippi Wednesday night at 50-70 percent. The 50-60 percent rain chances during the day Wednesday appear to be on the high side given the larger synoptic scale picture.

Beyond Wednesday night, the global models have weak disturbances in the flow aloft passing through the area Thursday and Friday. However, with northwest flow aloft across the area, moisture would be very limited suggesting a very high probability of dry conditions each day.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 1045 PM CDT Fri Jun 12 2026

A VFR TAF period into Sat morning as mid MS RVR Valley sfc high continues to pull off eastward up the OH RVR Valley. This will maintain light southerly sfc winds overnight. A frontal system will start to organize upstream off to the west through tomorrow morning, with south to southwest winds potentially becoming a bit gusty up to at least 20 KTs. With the incoming front comes the threat of more thunderstorms by Saturday afternoon and early evening, some of which may be strong to severe with damaging winds and large hail. Timing and placement remain an uncertainty with a few of the latest model runs having storms getting into the CID VCNTY by noon. But this is now an outlier as many CAMs have trended back to mid to later afternoon. Brunt of the strongest storms and higher coverage still appears may occur more west and southwest acrs southwest/south central IA into MO. This scenario would suggest the BRL site may have the highest chance of being impacted by a few rounds of storms. Also tricky timing a sfc wind veer to the west or northwest toward 00z or more likely through mid Saturday evening with the main FROPA. Other big wind changes and gusts may come earlier before the frontal passage from storm outflow/wake low wind gushes.

DVN WATCHES / WARNINGS / ADVISORIES

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