A tight low pressure system tracked its way out of north central Kansas on the 12th and slowly meandered northeast near the Nebraska, Kansas, Iowa borders by the early afternoon on the 13th.  A relatively stationary warm front draped itself across far southern Iowa, separating temperatures in the upper 70s to the south and 50s to low 60s to the north of the boundary respectively by the afternoon.  With the triple point in west to southwest Iowa, storms had little issue initiating by the mid-afternoon hours, quickly growing downstream both south and north of the warm front. With much of the Iowa north of the front, storms were elevated in nature, but produced large amounts of hail and damaging winds. The severe reports began just before 4pm and storms continued to remain near-severe to severe well into the evening, eventually transitioning away from hail as the primary threat and towards damaging winds.  Even as the severe storm threat diminished very strong winds remained, including gusts in excess of 60 mph, in the presence of a very tight surface pressure gradient. The same system produced blizzard conditions across northern Iowa on the 14th. Please see the separate entry for the blizzard portion of this event.

Thunderstorm Wind in GREENE, IOWA
From 13-APR-18 16:53:00 to 13-APR-18 16:53:00 (CST-6)
Location: JEFFERSON
Magnitude: 56.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Broadcast Media

KCIM Radio in Carroll relayed listener report of roof damage at McAtee Tire.  Also reported power outages. Time estimated from radar.

Thunderstorm Wind in GREENE, IOWA
From 13-APR-18 16:54:00 to 13-APR-18 16:54:00 (CST-6)
Location: JEFFERSON
Magnitude: 65.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Delayed report from a former TV meteorologist of damage to numerous buildings, trees, and power lines.  Based on damage, estimated wind speeds of 70 to 80 mph.

Thunderstorm Wind in GREENE, IOWA
From 13-APR-18 17:00:00 to 13-APR-18 17:00:00 (CST-6)
Location: JEFFERSON
Magnitude: 61.00 EG
Property damage: 150.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager relayed damages in Jefferson to several buildings and trees, power lines down, and trees on cars.

Thunderstorm Wind in HARDIN, IOWA
From 13-APR-18 19:15:00 to 13-APR-18 19:15:00 (CST-6)
Location: IOWA FALLS MUNI ARPT
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

AWOS recorded 59 mph wind gust.

Thunderstorm Wind in HARDIN, IOWA
From 13-APR-18 19:24:00 to 13-APR-18 19:24:00 (CST-6)
Location: CLEVES
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station in 3 miles north of Steamboat Rock recorded a 61 mph wind gust.

Thunderstorm Wind in BOONE, IOWA
From 13-APR-18 18:05:00 to 13-APR-18 18:05:00 (CST-6)
Location: MADRID
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Public reported shingles taken off of roof.

Thunderstorm Wind in DALLAS, IOWA
From 13-APR-18 19:54:00 to 13-APR-18 19:54:00 (CST-6)
Location: PANTHER
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported shingles off of roof, estimated 60 mph wind gusts.

Lightning in CASS, IOWA
From 13-APR-18 15:23:00 to 13-APR-18 15:23:00 (CST-6)
Location: LORAH
Property damage: 50.00K
Crop damage: 0.00K
Reported by: County Official

Cass County Public Safety reported a barn destroyed by a fire from a lightning strike.

Thunderstorm Wind in CASS, IOWA
From 13-APR-18 15:25:00 to 13-APR-18 15:25:00 (CST-6)
Location: MARNE
Magnitude: 52.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Delayed report from media in Atlantic of damage to outbuildings west of town.

Thunderstorm Wind in CASS, IOWA
From 13-APR-18 15:31:00 to 13-APR-18 15:31:00 (CST-6)
Location: LORAH
Magnitude: 52.00 EG
Property damage: 250.00K
Crop damage: 0.00K
Reported by: County Official

Delayed report from Cass County Public Safety of several campers blown over and damaged at an RV Sales lot.

Thunderstorm Wind in HARDIN, IOWA
From 13-APR-18 19:00:00 to 13-APR-18 19:15:00 (CST-6)
Location: HUBBARD
Magnitude: 65.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Public

Public reported that a building lost its roof in Hubbard, and 2 more homes between Hubbard and Iowa Falls sustained damage.

Thunderstorm Wind in STORY, IOWA
From 13-APR-18 18:30:00 to 13-APR-18 18:30:00 (CST-6)
Location: STORY CITY
Magnitude: 65.00 EG
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported that 130th Street from Highway 69 to 550th Street blocked due to power poles and lines down.

Thunderstorm Wind in STORY, IOWA
From 13-APR-18 18:32:00 to 13-APR-18 18:32:00 (CST-6)
Location: ROLAND
Magnitude: 56.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported semi blown over along I-35 at mile marker 119.

Hail in CRAWFORD, IOWA
From 13-APR-18 14:50:00 to 13-APR-18 14:50:00 (CST-6)
Location: DENISON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in GREENE, IOWA
From 13-APR-18 17:05:00 to 13-APR-18 17:05:00 (CST-6)
Location: CHURDAN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported up to quarter sized hail and that it was starting to cover the ground.

Hail in GREENE, IOWA
From 13-APR-18 17:15:00 to 13-APR-18 17:15:00 (CST-6)
Location: FARLIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported golf ball sized hail.

Hail in GREENE, IOWA
From 13-APR-18 17:23:00 to 13-APR-18 17:23:00 (CST-6)
Location: FARLIN
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar sized hail.

Hail in WEBSTER, IOWA
From 13-APR-18 17:23:00 to 13-APR-18 17:23:00 (CST-6)
Location: GOWRIE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported quarter sized hail.

Hail in WEBSTER, IOWA
From 13-APR-18 17:28:00 to 13-APR-18 17:28:00 (CST-6)
Location: GOWRIE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Hail in WEBSTER, IOWA
From 13-APR-18 17:31:00 to 13-APR-18 17:31:00 (CST-6)
Location: HARCOURT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported quarter sized hail.  Time estimated from radar.

Hail in WEBSTER, IOWA
From 13-APR-18 17:32:00 to 13-APR-18 17:32:00 (CST-6)
Location: GOWRIE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported a bit larger than half dollar sized hail.

Hail in HAMILTON, IOWA
From 13-APR-18 18:25:00 to 13-APR-18 18:25:00 (CST-6)
Location: STRATFORD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported pea to nickel sized hail in Stratford.

Hail in TAYLOR, IOWA
From 13-APR-18 18:33:00 to 13-APR-18 18:33:00 (CST-6)
Location: NEW MARKET
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported nickel sized hail.

Hail in TAYLOR, IOWA
From 13-APR-18 18:41:00 to 13-APR-18 18:41:00 (CST-6)
Location: GRAVITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public relayed pictures of dime to quarter sized hail.

Hail in TAYLOR, IOWA
From 13-APR-18 18:56:00 to 13-APR-18 18:56:00 (CST-6)
Location: SHARPSBURG
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Hail in TAYLOR, IOWA
From 13-APR-18 19:11:00 to 13-APR-18 19:11:00 (CST-6)
Location: LENOX
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported quarter sized hail.

Thunderstorm Wind in GREENE, IOWA
From 13-APR-18 16:45:00 to 13-APR-18 16:45:00 (CST-6)
Location: SCRANTON
Magnitude: 52.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operator reported wind driven hail caused broken windows.  Hail size unknown at the time.

Thunderstorm Wind in STORY, IOWA
From 13-APR-18 18:40:00 to 13-APR-18 18:40:00 (CST-6)
Location: STORY CITY
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported roof damage.

Thunderstorm Wind in CASS, IOWA
From 13-APR-18 15:30:00 to 13-APR-18 15:30:00 (CST-6)
Location: ATLANTIC ARPT
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

AWOS in Atlantic recorded a 61 mph wind gust.

Thunderstorm Wind in DALLAS, IOWA
From 13-APR-18 17:45:00 to 13-APR-18 17:45:00 (CST-6)
Location: PERRY MUNI ARPT
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

AWOS in Perry recorded a 61 mph wind gust.

Thunderstorm Wind in WEBSTER, IOWA
From 13-APR-18 18:05:00 to 13-APR-18 18:05:00 (CST-6)
Location: (FOD)FT DODGE MUNI A
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

AWOS in Fort Dodge recorded a 58 mph wind gust.

Thunderstorm Wind in GREENE, IOWA
From 13-APR-18 17:00:00 to 13-APR-18 17:00:00 (CST-6)
Location: JEFFERSON
Magnitude: 61.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported large campers flipped, power lines snapped, multiple buildings damaged.

High Wind in EMMET, IOWA
From 13-APR-18 18:45:00 to 13-APR-18 18:45:00 (CST-6)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Estherville ASOS measured a 59 mph wind gust.

High Wind in WRIGHT, IOWA
From 13-APR-18 21:15:00 to 13-APR-18 21:15:00 (CST-6)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Clarion AWOS recorded a 59 mph wind gust.

High Wind in BOONE, IOWA
From 13-APR-18 21:35:00 to 13-APR-18 21:35:00 (CST-6)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Boone AWOS recorded a 58 mph wind gust.

High Wind in WRIGHT, IOWA
From 13-APR-18 21:35:00 to 13-APR-18 21:35:00 (CST-6)
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Clarion AWOS recorded a 66 mph wind gust.

Thunderstorm Wind in CASS, IOWA
From 13-APR-18 15:23:00 to 13-APR-18 15:23:00 (CST-6)
Location: MARNE
Magnitude: 52.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: County Official

Delayed report from Cass County Public Safety about outbuilding damage, large tree limbs downed and outdoor furniture destroyed.

Thunderstorm Wind in MADISON, IOWA
From 13-APR-18 19:54:00 to 13-APR-18 19:54:00 (CST-6)
Location: WINTERSET
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Employee

Off-duty NWS Employee reports damage to a business sign on the north side of town.

Thunderstorm Wind in STORY, IOWA
From 13-APR-18 18:36:00 to 13-APR-18 18:36:00 (CST-6)
Location: STORY CITY
Magnitude: 75.00 EG
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency manager reported significant damage to 2 buildings and a tree blown down near a house. A semi-trailer was blown over at a warehouse.