Through much of the day of the 16th, a warm front slowly progressed into the state from the west, orienting itself north-south about a third to half of the way into the state.  As a result, storms were able to initiate and provide periods of heavy rainfall, numerous damaging wind reports, and a handful of severe hail reports.  Heavy rainfall amounts approached 2 to 3 inches across northern Iowa. The majority of severe wind reports occurred between 2 am and 4:30 am, heavy rainfall reports after around 7 am, and hail reports during redevelopment during the mid-late morning hours.

Hail in BUTLER, IOWA
From 17-JUL-16 09:33:00 to 17-JUL-16 09:33:00 (CST-6)
Location: DUMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported quarter sized hail on the NE side of Dumont.

Hail in FRANKLIN, IOWA
From 17-JUL-16 10:20:00 to 17-JUL-16 10:20:00 (CST-6)
Location: HAMPTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported mostly penny sized hail with a few up to the size of quarters.

Hail in BUTLER, IOWA
From 17-JUL-16 09:35:00 to 17-JUL-16 09:35:00 (CST-6)
Location: DUMONT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Sheriff reported a few half dollar sized hail stones on Highway 3.

Thunderstorm Wind in PALO ALTO, IOWA
From 17-JUL-16 01:08:00 to 17-JUL-16 01:08:00 (CST-6)
Location: GRAETTINGER
Magnitude: 61.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported an uprooted tree.  Time radar estimated.

Heavy Rain in CERRO GORDO, IOWA
From 17-JUL-16 00:30:00 to 17-JUL-16 04:36:00 (CST-6)
Location: CLEAR LAKE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter measured heavy rainfall of 1.64 inches. Beginning time radar estimated.

Heavy Rain in CERRO GORDO, IOWA
From 16-JUL-16 06:00:00 to 17-JUL-16 06:00:00 (CST-6)
Location: MASON CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer measured heavy rainfall of 3.03 inches over the last 24 hours.

Flash Flood in EMMET, IOWA
From 17-JUL-16 02:45:00 to 17-JUL-16 04:15:00 (CST-6)
Location: ESTHERVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported 6 to 8 inches of water on a few roads in Estherville.  Additional reports of farm fields flooded.  Location and time estimated.

Thunderstorm Wind in HARDIN, IOWA
From 17-JUL-16 02:56:00 to 17-JUL-16 02:56:00 (CST-6)
Location: ACKLEY
Magnitude: 56.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported several power lines and large trees down throughout the town of Ackley, as well as other portions of Hardin County.

Heavy Rain in WORTH, IOWA
From 16-JUL-16 06:00:00 to 17-JUL-16 06:00:00 (CST-6)
Location: NORTHWOOD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer measured heavy rainfall of 3.15 inches over the last 24 hours.

Heavy Rain in WINNEBAGO, IOWA
From 16-JUL-16 06:00:00 to 17-JUL-16 06:00:00 (CST-6)
Location: LAKE MILLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer measured heavy rainfall of 3.72 inches over the last 24 hours.

Flash Flood in EMMET, IOWA
From 17-JUL-16 01:15:00 to 17-JUL-16 04:15:00 (CST-6)
Location: ESTHERVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported 6 to 8 inches of water on a few roads in Estherville.  Additional report of a farm field flooded.  Location and time estimated.

Thunderstorm Wind in HARDIN, IOWA
From 17-JUL-16 02:59:00 to 17-JUL-16 02:59:00 (CST-6)
Location: STEAMBOAT ROCK
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported several large trees and power lines down in Steamboat Rock.  At least 2 power poles snapped in half just west of Steamboat Rock on D35.

Thunderstorm Wind in KOSSUTH, IOWA
From 17-JUL-16 01:32:00 to 17-JUL-16 01:32:00 (CST-6)
Location: LONE ROCK
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported a tree at least 1 foot in diameter downed onto the roadway.  Time and location estimated.

Flash Flood in PALO ALTO, IOWA
From 17-JUL-16 01:45:00 to 17-JUL-16 01:45:00 (CST-6)
Location: EMMETSBURG
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported various roadways with water 3 to 5 inches deep.  Time and location estimated.

Thunderstorm Wind in KOSSUTH, IOWA
From 17-JUL-16 01:37:00 to 17-JUL-16 01:37:00 (CST-6)
Location: BURT
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported a tree downed onto a house.  Time and location estimated.

Thunderstorm Wind in HUMBOLDT, IOWA
From 17-JUL-16 01:49:00 to 17-JUL-16 01:49:00 (CST-6)
Location: ARNOLD
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported a large tree downed onto Highway 169.

Thunderstorm Wind in HUMBOLDT, IOWA
From 17-JUL-16 01:56:00 to 17-JUL-16 01:56:00 (CST-6)
Location: BROCK RANCH ARPT
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported a machine shed destroyed.

Thunderstorm Wind in HUMBOLDT, IOWA
From 17-JUL-16 01:59:00 to 17-JUL-16 01:59:00 (CST-6)
Location: RENWICK
Magnitude: 65.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported one-third of a roof gone from an implement and farm supply store.  Additionally, a camper on its side, multiple power lines down, and large trees down throughout town blocking numerous streets.  A grain bin was also reported collapsed at the Co-op.

Thunderstorm Wind in HUMBOLDT, IOWA
From 17-JUL-16 01:59:00 to 17-JUL-16 01:59:00 (CST-6)
Location: THOR
Magnitude: 61.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported a large tree downed on top of a vehicle.

Thunderstorm Wind in HUMBOLDT, IOWA
From 17-JUL-16 02:01:00 to 17-JUL-16 02:01:00 (CST-6)
Location: THOR
Magnitude: 61.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported 4 machine sheds damaged/destroyed.  Time estimated from radar.

Heavy Rain in CERRO GORDO, IOWA
From 17-JUL-16 00:30:00 to 17-JUL-16 06:00:00 (CST-6)
Location: (MCW)MASON CITY MUNI
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mason City ASOS measured heavy rainfall of 2.74 inches.  Beginning time estimated.

Heavy Rain in EMMET, IOWA
From 16-JUL-16 06:00:00 to 17-JUL-16 06:00:00 (CST-6)
Location: RINGSTED
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer measured heavy rainfall of 2.49 inches over the last 24 hours.

Thunderstorm Wind in GRUNDY, IOWA
From 17-JUL-16 03:13:00 to 17-JUL-16 03:13:00 (CST-6)
Location: GRUNDY CENTER
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported trees and large branches down in town.  Time estimated from radar.  Report via social media.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-JUL-16 03:35:00 to 17-JUL-16 03:35:00 (CST-6)
Location: RAYMAR
Magnitude: 61.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported a shed and Morton building partially destroyed.  Numerous trees at least 12 to 18 inches in diameter snapped near their base as well.

Thunderstorm Wind in BLACK HAWK, IOWA
From 17-JUL-16 03:35:00 to 17-JUL-16 03:35:00 (CST-6)
Location: RAYMAR
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Broadcast Media

KWWL relayed reports of numerous 2 to 6 inch diameter tree limbs down in Raymar.  Time estimated from radar.

Heavy Rain in WINNEBAGO, IOWA
From 16-JUL-16 06:00:00 to 17-JUL-16 06:00:00 (CST-6)
Location: FOREST CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer measured heavy rainfall of 2.60 inches over the last 24 hours.

Heavy Rain in EMMET, IOWA
From 16-JUL-16 23:30:00 to 17-JUL-16 06:00:00 (CST-6)
Location: ESTHERVILLE ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Estherville ASOS station measured heavy rainfall of 2.21 inches.  Beginning time estimated.

Thunderstorm Wind in UNION, IOWA
From 17-JUL-16 06:57:00 to 17-JUL-16 06:57:00 (CST-6)
Location: KENT
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported tree limbs down and an auger blown over.  Damage occurred in Adams County on the Adams/Union counties line.

Thunderstorm Wind in WRIGHT, IOWA
From 17-JUL-16 02:03:00 to 17-JUL-16 02:03:00 (CST-6)
Location: GOLDFIELD
Magnitude: 56.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported multiple power lines and large trees down from Goldfield to Eagle Grove.

Thunderstorm Wind in WRIGHT, IOWA
From 17-JUL-16 02:07:00 to 17-JUL-16 02:07:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 56.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported several trees down around town.  Time radar estimated.

Thunderstorm Wind in WRIGHT, IOWA
From 17-JUL-16 02:07:00 to 17-JUL-16 02:07:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 61.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported several large trees down, either split in half or completely toppled over, throughout the town of Eagle Grove. One large tree fell on a house along West Broadway, along with several trees covering the street near the intersection of West Broadway and Fort.

Thunderstorm Wind in WRIGHT, IOWA
From 17-JUL-16 02:07:00 to 17-JUL-16 02:07:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 56.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported downed trees and debris blocking roadway IA 17.  Time radar estimated.

Heavy Rain in EMMET, IOWA
From 16-JUL-16 06:00:00 to 17-JUL-16 06:00:00 (CST-6)
Location: ESTHERVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coop observer measured heavy rainfall of 2.08 inches over the last 24 hours.

Heavy Rain in CLARKE, IOWA
From 17-JUL-16 07:40:00 to 17-JUL-16 08:41:00 (CST-6)
Location: MURRAY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported heavy rainfall of 1.40 inches over roughly 50 minutes. Beginning time radar estimated.

Hail in FRANKLIN, IOWA
From 17-JUL-16 09:12:00 to 17-JUL-16 09:12:00 (CST-6)
Location: HAMPTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Hail in BUTLER, IOWA
From 17-JUL-16 09:13:00 to 17-JUL-16 09:13:00 (CST-6)
Location: DUMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter sized hail.

Thunderstorm Wind in WEBSTER, IOWA
From 17-JUL-16 02:08:00 to 17-JUL-16 02:08:00 (CST-6)
Location: FT DODGE
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported trees down around town.

Thunderstorm Wind in HARDIN, IOWA
From 17-JUL-16 03:04:00 to 17-JUL-16 03:04:00 (CST-6)
Location: CLEVES
Magnitude: 76.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Steamboat Rock RWIS measured sustained winds of 55 mph, including an 88 mph wind gust.

Thunderstorm Wind in WRIGHT, IOWA
From 17-JUL-16 02:07:00 to 17-JUL-16 02:07:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported peak winds estimated at 60 to 70 mph.

Thunderstorm Wind in HARDIN, IOWA
From 17-JUL-16 02:37:00 to 17-JUL-16 02:37:00 (CST-6)
Location: IOWA FALLS
Magnitude: 56.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported several power lines and large trees down throughout the town of Alden.

Thunderstorm Wind in HAMILTON, IOWA
From 17-JUL-16 02:41:00 to 17-JUL-16 02:41:00 (CST-6)
Location: JEWELL
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported trees and large branches down at Jewell Golf and Country Club.  Reported via social media.

Flash Flood in CERRO GORDO, IOWA
From 17-JUL-16 02:45:00 to 17-JUL-16 05:30:00 (CST-6)
Location: MASON CITY
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported 1st street blocked off with water 3 to 4 feet deep and a submerged vehicle.  Various locations across Mason City with 4 to 6 inches deep. Time and location estimated.