A relatively stationary frontal boundary remained over Iowa on the 9th, a day after the same boundary produced a couple of tornadoes, strong storms, and heavy rainfall. In similar fashion, the environment was conducive for rotating storms. Running down the list of conducive features, LCLs were under 1000m, SBCAPE values were in the 1000-2000 J/kg range, effective bulk shear was in excess of 40kts, and effective storm relative helicity was in excess of 200 m2/s2. All in all, it was not going to take much for storms to rotate and have the potential to product funnel clouds and at least brief tornadoes. Scattered showers and storms were persistent through the afternoon and early evening, with a number producing brief tornadoes.

Tornado in APPANOOSE, IOWA
From 09-OCT-18 14:24:00 to 09-OCT-18 14:27:00 (CST-6)
Location: CENTERVILLE ARPT
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The tornado developed near the Centerville Municipal Airport with one of the hangars sustaining EF0 damage.  The tornado proceeded through cropland up to the southwest outskirts of Centerville before dissipating.

Tornado in POWESHIEK, IOWA
From 09-OCT-18 15:20:00 to 09-OCT-18 15:21:00 (CST-6)
Location: BROOKLYN ARPT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous spotters reported a tornado north of Brooklyn.  The tornado traveled north for a brief distance across cropland in Poweshiek County before entering Tama County.  Only minor crop damage occurred in Poweshiek County.

Tornado in BLACK HAWK, IOWA
From 09-OCT-18 16:21:00 to 09-OCT-18 16:24:00 (CST-6)
Location: BOIES
Tornado F-scale: EF0
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado developed in far northern Black Hawk County and moved due north through open cropland.   The tornado encountered a house along West Gresham Road just east of Leversee Road and produced EF0 damage to trees and shingles.  The tornado then moved north into open cropland and was captured on video for the remainder of its path, crossing into Bremer County before dissipating.

Tornado in ADAIR, IOWA
From 09-OCT-18 16:42:00 to 09-OCT-18 16:47:00 (CST-6)
Location: ZION
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 1.00K
Reported by: Emergency Manager

Tornado was determined by a tornadic debris signature on radar and subsequently found via high resolution satellite imagery.   Any damage was to crops as the tornado remained across rural agricultural land east of Orient.

Tornado in TAMA, IOWA
From 09-OCT-18 15:21:00 to 09-OCT-18 15:25:00 (CST-6)
Location: HAVEN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous spotter reported this tornado as it moved from Poweshiek into Tama County.  This tornado remained in open cropland with little if any damage.

Tornado in ADAIR, IOWA
From 09-OCT-18 16:58:00 to 09-OCT-18 17:01:00 (CST-6)
Location: ARBOR HILL
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado developed just south of the hamlet of Arbor Hill and produced minor tree damage along the Stuart Road.  The tornado moved northeast and remained over cropland with little damage noted.  Portions of the path were observed using high resolution satellite imagery.

Funnel Cloud in TAMA, IOWA
From 09-OCT-18 15:41:00 to 09-OCT-18 15:41:00 (CST-6)
Location: GLADSTONE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager relayed public reports of two funnel clouds in the area.

Tornado in APPANOOSE, IOWA
From 09-OCT-18 14:34:00 to 09-OCT-18 14:35:00 (CST-6)
Location: FORBUSH
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Brief tornado reported by a storm chaser south of Rathbun.  This tornado stayed in rural crop and grazing land with little to no damage.

Tornado in POWESHIEK, IOWA
From 09-OCT-18 15:14:00 to 09-OCT-18 15:18:00 (CST-6)
Location: MALCOLM
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado developed west of the hamlet of Ewart and moved due north.  Tornado remained in rural agricultural land with little damage.

Tornado in BREMER, IOWA
From 09-OCT-18 16:24:00 to 09-OCT-18 16:25:00 (CST-6)
Location: JANESVILLE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado moved into Bremer County from Black Hawk County.  The tornado remained over open cropland before dissipating with little if any damage.

Tornado in RINGGOLD, IOWA
From 09-OCT-18 15:35:00 to 09-OCT-18 15:41:00 (CST-6)
Location: CLEARFIELD
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

Tornado developed in rural western Ringgold county and moved almost due north across open cropland.  Little damage was noted.  Tornado was found using high resolution satellite imagery.

Tornado in UNION, IOWA
From 09-OCT-18 16:09:00 to 09-OCT-18 16:15:00 (CST-6)
Location: CROMWELL
Tornado F-scale: EF1
Property damage: 40.00K
Crop damage: 1.00K
Reported by: NWS Storm Survey

This tornado developed between Creston and Cromwell in western Union county and traveled on a somewhat unusual northwest path.  Tornado was mostly in open rural cropland for nearly two miles producing only crop damage.  However, the tornado encountered farmsteads along Clover Avenue about one half mile south of 170th Street.  A garage was destroyed on the west side of the road and was rated EF1 damage given generally poor construction.  Additional EF1 damage was observed with the nearby house with a portion of the roof and truss structure removed.  Tree damage was observed across the road at an adjacent house.  Additional minor damage was found about one quarter mile farther up the road with the last damage noted north of 170th Street on the west side of the road where a few roof panels were blown off an old metal shed.

Tornado in ADAIR, IOWA
From 09-OCT-18 17:03:00 to 09-OCT-18 17:08:00 (CST-6)
Location: ARBOR HILL
Tornado F-scale: EF1
Property damage: 5.00K
Crop damage: 1.00K
Reported by: NWS Storm Survey

Tornado developed just east of the Stuart Road in open cropland.  The tornado moved on a slightly unusual northwest track eventually crossing the Stuart Road about one half mile south of 150th Street.  The tornado produced EF1 damage to outbuildings and trees at a farmstead on the southwest intersection of 150th & Stuart Road.  The tornado then moved back into cropland with only some minor tree and crop damage noted until it dissipated.