The hits just kept on rolling, with yet another pair of rounds of strong to severe storms, heavy rainfall, and flooding. Through much of the end of May, the synoptic setup across the region remained relatively unchanged, including this event. Upper level flow continued to be out of the SW, precipitable water values remained in excess of 1.5 inches, and a relatively stationary boundary remained over the area. In addition to that broad setup, MUCAPE values hovered in the 1000-2000 J/kg range, bulk effective shear was supportive in the 40 to 60 kts range, and low level moisture flow continued to move into the area.
The 28th saw two rounds of strong to severe storms move through from the west and southwest, each causing at least a few severe reports and contributing to overall heavy rainfall and eventually flash flooding. Severe reports were generally relegated to west central and southwest Iowa, where storms were strongest and able to utilize the greatest amounts of effective bulk shear, while heavy rainfall and flash flooding prevailed over already wet areas of south-central and southeastern Iowa. Fortunately flash flooding was predominantly relegated to road closures, though some flooding did linger into the 29th.
Note, the morning round of strong to severe storms is covered in another Storm Data event entry (27-28 May 2019).

Hail in MARION, IOWA
From 28-MAY-19 14:33:00 to 28-MAY-19 14:33:00 (CST-6)
Location: ATTICA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported nickel to quarter sized hail in addition to very heavy rainfall near Attica.

Flash Flood in APPANOOSE, IOWA
From 28-MAY-19 18:47:00 to 29-MAY-19 22:00:00 (CST-6)
Location: EXLINE
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported water over the road near Highway 5 and T30 blocking poeple from leaving their residences.

Heavy Rain in WAYNE, IOWA
From 28-MAY-19 00:30:00 to 28-MAY-19 18:47:00 (CST-6)
Location: SEYMOUR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 3.22 inches. Beginning time estimated from radar.

Flash Flood in TAYLOR, IOWA
From 28-MAY-19 17:52:00 to 29-MAY-19 00:00:00 (CST-6)
Location: BEDFORD ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported water covering 317th street between Orange and Montana.

Flood in APPANOOSE, IOWA
From 28-MAY-19 22:00:00 to 29-MAY-19 22:00:00 (CST-6)
Location: GRIFFINSVILLE
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 100.00K
Reported by: Emergency Manager

Emergency manager reported multiple secondary roads remained under water or closed and a few culverts damaged or destroyed in Appanoose County from the heavy rainfall and subsequent overland and river flooding.

Hail in MARION, IOWA
From 28-MAY-19 14:36:00 to 28-MAY-19 14:36:00 (CST-6)
Location: BUSSEY
Magnitude: 1.25 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported ping pong ball sized hail.

Flash Flood in MONROE, IOWA
From 28-MAY-19 17:14:00 to 29-MAY-19 22:00:00 (CST-6)
Location: WELLER
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported that several secondary roads in Monroe and Davis Counties have water over them and will be barricaded and closed. Debris in streams also a concern for damaging culverts.

Flash Flood in WAPELLO, IOWA
From 28-MAY-19 15:49:00 to 29-MAY-19 22:00:00 (CST-6)
Location: EDDYVILLE
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported flowing water over both lanes of Highway 63 at mile marker 53 just south of Eddyville. Depth unknown at the time.

Flash Flood in WAYNE, IOWA
From 28-MAY-19 17:12:00 to 29-MAY-19 22:00:00 (CST-6)
Location: PROMISE CITY
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

WHO TV reported water over the road on Highway 2 east of Promise City.

Flash Flood in APPANOOSE, IOWA
From 28-MAY-19 18:47:00 to 29-MAY-19 22:00:00 (CST-6)
Location: SHARON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported high water on Highway 2 underneath the railroad overpass.

Flood in MAHASKA, IOWA
From 28-MAY-19 21:00:00 to 29-MAY-19 14:00:00 (CST-6)
Location: BEACON
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 25.00K
Reported by: Official NWS Observations

The Muchakinock Creek gauge went into flood during the evening hours on the 28th and continued into the early afternoon hours of the 29th. Water goes over the road on Highway 92 west of Oskaloosa when it is flooding.

Flash Flood in MONROE, IOWA
From 28-MAY-19 17:02:00 to 29-MAY-19 22:00:00 (CST-6)
Location: HITEMAN
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT reported that Monroe County was closing 602nd Ave near Cedar Creek.

Flash Flood in MONROE, IOWA
From 28-MAY-19 16:57:00 to 29-MAY-19 22:00:00 (CST-6)
Location: HITEMAN
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Department of Highways

Iowa DOT reported that Monroe County is closing 614th Ave due to water over the road.

Flash Flood in DAVIS, IOWA
From 28-MAY-19 17:14:00 to 29-MAY-19 22:00:00 (CST-6)
Location: ASH GROVE
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported that several secondary roads in Monroe and Davis Counties have water over them and will be barricaded and closed. Debris in streams also a concern for damaging culverts.

Flood in ADAIR, IOWA
From 28-MAY-19 13:30:00 to 28-MAY-19 23:00:00 (CST-6)
Location: CANBY
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 50.00K
Reported by: Law Enforcement

Water was reported over 120th St just east of Highway 25 near the Freedom Rock, which was overflow from the Middle River. Several gravel roads were flooded in and around the Middle River across Adair County.

Flood in MONROE, IOWA
From 28-MAY-19 22:00:00 to 29-MAY-19 22:00:00 (CST-6)
Location: MELROSE
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 100.00K
Reported by: Emergency Manager

Emergency manager reported multiple secondary roads remained under water or closed in Monroe County from the heavy rainfall yesterday and subsequent overland and river flooding.

Flood in LUCAS, IOWA
From 28-MAY-19 22:00:00 to 29-MAY-19 22:00:00 (CST-6)
Location: WILLIAMSON
Flood cause: Heavy Rain
Property damage: 80.00K
Crop damage: 50.00K
Reported by: Emergency Manager

Emergency manager reported multiple secondary roads remained under water or closed  in Lucas County from the heavy rainfall and subsequent overland and river flooding.

Flood in DAVIS, IOWA
From 28-MAY-19 22:00:00 to 29-MAY-19 22:00:00 (CST-6)
Location: ASH GROVE
Flood cause: Heavy Rain
Property damage: 300.00K
Crop damage: 100.00K
Reported by: Emergency Manager

Emergency manager reported multiple secondary secondary roads remained under water or closed, a few culverts known to be damaged or destroyed, and one rural wood truss bridge lost in Davis County from the rainfall and subsequent overland and river flooding yesterday. The Fox River rose over 15 feet in 5 hours at Bloomfield. A rural truss wooden bridge was damaged.

Heavy Rain in CLARKE, IOWA
From 28-MAY-19 06:00:00 to 28-MAY-19 16:18:00 (CST-6)
Location: MURRAY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported some small hail and heavy rainfall of 2.05 inches since 7am.

Heavy Rain in WAYNE, IOWA
From 28-MAY-19 00:30:00 to 28-MAY-19 16:42:00 (CST-6)
Location: SEYMOUR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported heavy rainfall of 2.20 inches so far today, and 1.7 inches since 330pm. Beginning time estimated from radar.

Flood in MAHASKA, IOWA
From 28-MAY-19 21:00:00 to 29-MAY-19 14:00:00 (CST-6)
Location: BEACON
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 100.00K
Reported by: Official NWS Observations

The Muchakinock Creek gauge went into flood during the evening hours on the 28th and continued into the early afternoon hours of the 29th. Water goes over the road on Highway 92 west of Oskaloosa when it is flooding.