Convection percolated along a warm front across the area through the morning. By afternoon, storms re-strengthened as as daytime heating helped enhance instability. Despite good instability with MLCAPE over nearing 2000 J/kg, lapse rates were modest and speed shear was weak. Despite this, directional shear was good and when combined with instability for brief stretching, allowed for a number of weak and short-lived tornadoes to develop. While 13 tornadoes occurred, they were confined to two small areas in Iowa where storms trained, resulting in several storms over the same locations. In addition, the training storms made for pockets of heavy rain with three to four inches or more of rain. This did result in flash flooding in Pocahontas County with impacts to homes and businesses.

Tornado in CALHOUN, IOWA
From 13-MAY-23 15:51:00 to 13-MAY-23 15:53:00 (CST-6)
Location: KNOKE
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado reported by storm chaser southwest of Fonda. No damage indicators were impacted, therefore the EFU rating.

Tornado in GREENE, IOWA
From 13-MAY-23 16:18:00 to 13-MAY-23 16:20:00 (CST-6)
Location: SCRANTON
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado east of Scranton captured by storm chaser. Tornado remained in open fields with no impact to damage indicators, hence the EFU rating.

Tornado in MARION, IOWA
From 13-MAY-23 17:20:00 to 13-MAY-23 17:21:00 (CST-6)
Location: NEPAS
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado reported by storm chaser. No damage indicators were impacted, hence the EFU rating.

Flash Flood in POCAHONTAS, IOWA
From 13-MAY-23 20:00:00 to 14-MAY-23 00:45:00 (CST-6)
Location: LAURENS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Delayed report of extensive flooding in town. Water up against some homes and businesses in town. Time estimated.

Tornado in CALHOUN, IOWA
From 13-MAY-23 17:22:00 to 13-MAY-23 17:24:00 (CST-6)
Location: POMEROY
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tornado developed east of Pomeroy and moved north passing into Pocahontas county shortly after forming.  The tornado remained in open fields in Calhoun county and did not impact any damage indicators, hence the EFU rating for this portion of the path.

Tornado in POCAHONTAS, IOWA
From 13-MAY-23 17:24:00 to 13-MAY-23 17:27:00 (CST-6)
Location: BLANDEN
Tornado F-scale: EF0
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tornado developed east of Pomeroy and moved north from Calhoun into Pocahontas county. Upon entering Pocahontas county, the tornado produced some damage to grain bins and an outbuilding. The remainder of the path was over open cropland.

Tornado in POCAHONTAS, IOWA
From 13-MAY-23 17:26:00 to 13-MAY-23 17:28:00 (CST-6)
Location: WARE
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado caught on video northwest of Pocahontas. It appears no damage indicators were impacted, hence the EFU rating.

Tornado in MARION, IOWA
From 13-MAY-23 17:52:00 to 13-MAY-23 17:55:00 (CST-6)
Location: DONNELLY
Tornado F-scale: EF0
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A brief tornado occurred north of Highway 5 captured by many chasers. There was some tree damage produced by the tornado before dissipating.

Tornado in POCAHONTAS, IOWA
From 13-MAY-23 17:52:00 to 13-MAY-23 17:54:00 (CST-6)
Location: WESTVIEW
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A brief tornado was sighted by law enforcement passing across open farmland. No damage indicators were impacted, hence the EFU rating.

Tornado in POCAHONTAS, IOWA
From 13-MAY-23 18:22:00 to 13-MAY-23 18:24:00 (CST-6)
Location: HAVELOCK
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Brief tornado that remained in open cropland. No damage indicators were impacted, hence the EFU rating.

Tornado in WARREN, IOWA
From 13-MAY-23 12:22:00 to 13-MAY-23 12:24:00 (CST-6)
Location: SANDYVILLE
Tornado F-scale: EF0
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Storm Chaser

Storm Chaser has video of the weak tornado passing across rural portions of Warren county.  Some minor tree damage occurred.  This tornado then proceeded into Marion county.

Hail in MARION, IOWA
From 13-MAY-23 14:26:00 to 13-MAY-23 14:26:00 (CST-6)
Location: KNOXVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Report from KNIA radio of quarter inch hail occurring at their studio.

Heavy Rain in MARION, IOWA
From 13-MAY-23 12:30:00 to 13-MAY-23 15:30:00 (CST-6)
Location: KNOXVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Over three inches of rain with standing water and street flooding in town.

Heavy Rain in POCAHONTAS, IOWA
From 12-MAY-23 17:50:00 to 13-MAY-23 17:50:00 (CST-6)
Location: LAURENS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A 24 hour total of 6.90 inches of rain, with 3.5 inches of that occurring in the last one hour.

Tornado in MARION, IOWA
From 13-MAY-23 12:24:00 to 13-MAY-23 12:26:00 (CST-6)
Location: PLEASANTVILLE
Tornado F-scale: EF0
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Storm Chaser

This tornado entered into Marion county from Warren county.  The tornado was captured on video by several storm chasers.  Some minor tree damage occurred with this tornado as it remained in rural Marion county.

Tornado in SAC, IOWA
From 13-MAY-23 12:36:00 to 13-MAY-23 12:37:00 (CST-6)
Location: SCHALLER
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado captured on video by a storm chaser northeast of Schaller. Tornado remained in open crop field with no impacts to damage indicators, hence the EFU rating.

Tornado in MARION, IOWA
From 13-MAY-23 14:23:00 to 13-MAY-23 14:25:00 (CST-6)
Location: FLAGLER
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado captured on imagery and reported by a storm chaser. Tornado did not impact any damage indicators, hence the EFU rating.

Heavy Rain in PALO ALTO, IOWA
From 13-MAY-23 17:15:00 to 13-MAY-23 19:15:00 (CST-6)
Location: MALLARD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 2.69 inch of rain thus far, rain still falling.

Heavy Rain in POCAHONTAS, IOWA
From 13-MAY-23 17:00:00 to 13-MAY-23 19:20:00 (CST-6)
Location: WESTVIEW
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 3.30 inches thus far, rain still falling.

Heavy Rain in MARION, IOWA
From 13-MAY-23 12:44:00 to 13-MAY-23 20:44:00 (CST-6)
Location: FIFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 4.22 inches.

Tornado in MARION, IOWA
From 13-MAY-23 14:29:00 to 13-MAY-23 14:31:00 (CST-6)
Location: FLAGLER
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Another brief tornado which produced minor damage to an outbuilding and a hoop building.  The tornado was captured on video by a storm chaser.

Tornado in MARION, IOWA
From 13-MAY-23 14:52:00 to 13-MAY-23 14:54:00 (CST-6)
Location: DURHAM
Tornado F-scale: EF0
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Tornado was captured on video by storm chasers. Some minor EF0 tree damage occurred with this tornado prior to lifting northwest of Harvey.

Tornado in POCAHONTAS, IOWA
From 13-MAY-23 15:15:00 to 13-MAY-23 15:19:00 (CST-6)
Location: FONDA
Tornado F-scale: EFU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Intermittent tornado with well developed funnel on video from storm chaser. No damage indicators were impacted, hence the EFU rating.

Heavy Rain in MARION, IOWA
From 13-MAY-23 12:46:00 to 13-MAY-23 20:46:00 (CST-6)
Location: PELLA MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 3.28 inches.

Heavy Rain in POCAHONTAS, IOWA
From 13-MAY-23 17:00:00 to 13-MAY-23 20:49:00 (CST-6)
Location: ROLFE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 4.25 inches.

Heavy Rain in POCAHONTAS, IOWA
From 13-MAY-23 17:00:00 to 13-MAY-23 20:50:00 (CST-6)
Location: VARINA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 4.95 inches.

Heavy Rain in POCAHONTAS, IOWA
From 13-MAY-23 17:00:00 to 13-MAY-23 20:51:00 (CST-6)
Location: HAVELOCK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 2.96 inches.

Heavy Rain in PALO ALTO, IOWA
From 13-MAY-23 17:00:00 to 13-MAY-23 20:55:00 (CST-6)
Location: MALLARD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 4.67 inches.

Heavy Rain in PALO ALTO, IOWA
From 13-MAY-23 16:56:00 to 13-MAY-23 20:56:00 (CST-6)
Location: WEST BEND
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Storm total of 4.67 inches.