After an early morning flash flood event in eastern Iowa, with some damaging winds near the Mississippi River, a line of slow moving supercell thunderstorms moved southeast from northern Iowa, into portions of eastern Iowa the evening of June 9th. Damaging winds, large hail, a few tornadoes, and torrential rain accompanied the storms.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DVN wrote it up.
After an early morning flash flood event in eastern Iowa, with some damaging winds near the Mississippi River, a line of slow moving supercell thunderstorms moved southeast from northern Iowa, into portions of eastern Iowa the evening of June 9th. Damaging winds, large hail, a few tornadoes, and torrential rain accompanied the storms. This event brought flash flooding, and led to some minor to moderate river flooding on the Cedar, Iowa, and Wapsipinicon Rivers.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Quad Cities, IA wrote its last area forecast discussion before the first event at Jun 9, 2:39 AM CST, 36 minutes earlier.
Area Forecast Discussion National Weather Service Quad Cities IA IL 339 AM CDT Sat Jun 9 2018 .SYNOPSIS... Issued at 338 AM CDT Sat Jun 9 2018 Low level moisture transport of high PWAT air was riding up over a stalled boundary that extended from central IA, to se IA to central IL. Thunderstorms have been rather numerous north of the boundary across portions of eastern IA and nw IL. Some of these storms have dumped heavy rainfall with doppler radar estimating up to 5 inches in sw Rock Island county (that particular storm was stationary for a couple of hours). Meanwhile, a rather long-lived MCS was pushing into eastern NE and has been producing wind damage and large hail. && .SHORT TERM...(Today and Tonight) ISSUED AT 338 AM CDT Sat Jun 9 2018 Forecast focus on re-development of storms. Today: LLJ should weaken and veer westerly for a time this morning, allowing for a diminishing trend in the thunderstorms across portions of eastern IA and nw IL. The late morning and early afternoon hours should be mainly dry (can't rule out some isolated showers or storms). The MCS out west should weaken considerably as it pushes into central IA this morning. Assuming enough sunshine this afternoon the atmosphere should reload later and the LLJ (albeit weak) backs again to the southwest. The weakening MCS may produce a boundary or MCV for additional storms to fire on as the afternoon progesses, which is supported by the NAMNEST/HRRR. Shear will remain rather weak, but SBCAPES should rise to at least 4000 j/kg which would support multi-cell clusters or bowing segments with damaging winds/large hail. For now SPC has a marginal risk across the dvn cwa, but this will need to be monitored for a possible upgrade to slight in portions of the area. Highs will be in the 80s to around 90. Tonight: At least scattered to numerous thunderstorms will continue as the LLJ once again impinges on a stalled boundary across the area. A few storms may be severe and also produce torrential rainfall. Lows will be in the 60s. .LONG TERM...(Sunday through Friday) ISSUED AT 338 AM CDT Sat Jun 9 2018 Sunday and Monday: The pattern remains locked in place with the dvn cwa on the edge of the heat dome. Rounds of thunderstorms should continue and some of these storms may be severe. SPC has a marginal risk for both days. Later on Monday into Monday night a somewhat stronger cold front arrives. This looks to be a better set-up for severe as deep layer shear should be stronger. SPC has a slight risk in southern MN/central IA/nw MO but this will need to be monitored to see if these storms can remain severe as they push into the dvn cwa probably Monday evening. Highs should be well into the 80s to lower 90s. Tuesday and Wednesday: With the passage of the cold front this looks to be a quiet period with comfortable temperatures and humidity. Highs will be in the 70s to lower 80s with lows in the 50s to lower 60s. Thursday and Friday: The heat dome builds back northward putting the area into the active pattern once again, with several rounds of thunderstorms possible. However, this far out it is difficult to determine the timing/location of MCS's or the severe risk. Highs will push well into the 80s to near 90 once again. && .AVIATION...(For the 06Z TAFS through 06Z Saturday Night) ISSUED AT 120 AM CDT Sat Jun 9 2018 MVFR cigs/vis in/near tstms othw VFR conds to prevail. Scattered thunderstorms early this morning impacting KDBQ/KMLI terminals. Then more storms developing this afternoon and evening. Low confidence in coverage so will mention only VCTS for now. Southeast to south winds around 10 knots or less. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && SYNOPSIS...Haase SHORT TERM...Haase LONG TERM...Haase AVIATION...Haase
Hazardous Weather Outlook National Weather Service Quad Cities IA IL 414 AM CDT Sat Jun 9 2018 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-100915- Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson- Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson- Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll- Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson- Warren-Hancock-McDonough-Scotland-Clark- 414 AM CDT Sat Jun 9 2018 This Hazardous Weather Outlook is for portions of north central Illinois...northwest Illinois...west central Illinois...east central Iowa...northeast Iowa...southeast Iowa and northeast Missouri. .DAY ONE...TODAY AND TONIGHT The Storm Prediction Center has a marginal risk for severe storms across the outlook area today and tonight. Numerous thunderstorms in portions of eastern Iowa and northwest Illinois should diminish this morning. Some of the storms will produce torrential rainfall, frequent lightning and small hail. Thunderstorms should re-develop later this afternoon and continue into tonight. Some of the storms may be severe with large hail and damaging winds the main threat. Torrential rain and frequent lightning will also accompany these storms. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY The Storm Prediction Center has a marginal risk for severe storms across the outlook area for Sunday and Monday. Additional rounds of thunderstorms can be expected Sunday and Monday, as a cold front gradually pushes towards the area. Some of these storms may be severe with large hail and damaging winds the main threat. The cold front will push across the area by Monday night. Thursday and Friday: More chances for thunderstorms can be expected. However, it is too early to determine the severe risk for late next week. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed especially later this afternoon and into tonight. Haase
Special Weather Statement
National Weather Service Quad Cities IA/IL
1100 PM CDT FRI JUN 8 2018
IAC031-103-090500-
Cedar-Johnson-
1100 PM CDT FRI JUN 8 2018
...A STRONG THUNDERSTORM WILL AFFECT WESTERN CEDAR AND EAST CENTRAL
JOHNSON COUNTIES UNTIL MIDNIGHT CDT...
At 1100 PM CDT, a strong thunderstorm was located over West Branch,
moving northeast at 10 mph.
Dime size hail is possible with this storm.
Locations impacted include...
Tipton, West Branch, Rochester, Buchanan, Springdale, Cedar Valley,
Cedar Bluff, Oasis, Elmira, Cedar Valley Park, Morse, Herbert Hoover
National Historic Site, Tipton Matthews Airport, Cedar County
Fairgrounds and Newport.
This includes Interstate 80 in Iowa between mile markers 250 and 270.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4188 9118 4164 9102 4160 9122 4160 9136
4156 9137 4156 9138 4173 9148
TIME...MOT...LOC 0400Z 244DEG 11KT 4168 9134
ErvinSpecial Weather Statement
National Weather Service Quad Cities IA/IL
1101 PM CDT FRI JUN 8 2018
IAC031-045-163-090500-
Cedar-Scott-Clinton-
1101 PM CDT FRI JUN 8 2018
...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL CEDAR...NORTHERN
SCOTT AND SOUTHWESTERN CLINTON COUNTIES UNTIL MIDNIGHT CDT...
At 1101 PM CDT, a strong thunderstorm was located near Bennett, or 7
miles north of Durant, moving northeast at 15 mph.
Pea size hail is possible with this storm.
Locations impacted include...
Durant, DeWitt, Walcott, Long Grove, Wheatland, Grand Mound, Calamus,
Bennett, Donahue, Welton, Dixon, Maysville, New Liberty, Camp
Liberty, Bennett Park, Big Rock, Sunbury, Sherman Park and Clinton
County Fairgrounds.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4195 9059 4170 9044 4160 9086 4160 9090
4175 9099
TIME...MOT...LOC 0401Z 244DEG 11KT 4171 9086
ErvinSpecial Weather Statement National Weather Service Quad Cities IA/IL 1208 AM CDT SAT JUN 9 2018 ILC131-161-090545- Rock Island-Mercer- 1208 AM CDT SAT JUN 9 2018 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN ROCK ISLAND AND NORTHEASTERN MERCER COUNTIES UNTIL 1245 AM CDT... At 1207 AM CDT, a strong thunderstorm was located near Illinois City, or 11 miles north of Aledo, moving northeast at 5 mph. Winds in excess of 30 mph and dime size hail are possible with this storm. Locations impacted include... Rock Island, Andalusia, Matherville, Reynolds, Hamlet, Illinois City, Taylor Ridge, Boden, Preemption, Edgington, Gingle Corners, Marston and Loud Thunder Scout Camp. Torrential rainfall is also occurring with this storm, and may cause localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. LAT...LON 4128 9087 4142 9093 4144 9060 4123 9057 TIME...MOT...LOC 0507Z 234DEG 5KT 4136 9083 Sheets
Special Weather Statement National Weather Service Quad Cities IA/IL 218 AM CDT SAT JUN 9 2018 IAC045-097-090745- Jackson-Clinton- 218 AM CDT SAT JUN 9 2018 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN JACKSON AND NORTHWESTERN CLINTON COUNTIES UNTIL 245 AM CDT... At 218 AM CDT, a strong thunderstorm was located over Nashville, or 8 miles west of Maquoketa, moving east at 10 mph. Winds in excess of 30 mph and nickel size hail are possible with this storm. Locations impacted include... Maquoketa, Delmar, Lost Nation, Andrew, Charlotte, Welton, Monmouth, Springbrook, Toronto, Nashville, Hurstville, Fulton, Baldwin, Eden Valley Refuge, Maquoketa Caves State Park, Maquoketa Municipal Airport, Jackson County Fairgrounds, Buckhorn, Elwood and Walnut Grove Park. Torrential rainfall is also occurring with this storm, and may cause localized flooding. Do not drive your vehicle through flooded roadways. LAT...LON 4188 9089 4211 9090 4219 9046 4188 9044 TIME...MOT...LOC 0718Z 287DEG 8KT 4204 9082 Sheets
Special Weather Statement National Weather Service Quad Cities IA IL 411 AM CDT Sat Jun 9 2018 IAZ054-066-ILZ007-009-091115- Jackson-Clinton-Carroll-Whiteside- Including the cities of Maquoketa, Clinton, Mount Carroll, and Sterling 411 AM CDT Sat Jun 9 2018 ...THUNDERSTORMS WITH HEAVY RAIN MAY LEAD TO MINOR FLOODING... At 4 AM CDT...Doppler radar indicated slow moving thunderstorms with frequent lightning and very heavy rainfall continuing to impact much of Jackson, Clinton, Carroll and Whiteside counties in far eastern Iowa and northwest Illinois. Radar estimates indicated rainfall amounts from 1 to locally 3 inches has fallen from storms in this area over the past 3 hours. An additional 1 to 2 inches of rain will be possible before storms exit the region around sunrise. Excessive runoff from heavy rainfall may lead to flooding of small creeks and streams, country roads, farmland, and other low lying spots. If you encounter a flooded roadway, turn around. Most flood deaths occur in vehicles. Sheets
The Quad Cities radar (KDVN), 40 km away, was scanning. The volume nearest the first event began at 09:14 UTC.
11 thunderstorm wind, 9 hail, 6 flash flood, 1 tornado. Local standard time, as filed.
The mayor of Charlotte Iowa reported flash flooding of creeks in town.
The wind was measured at the Clinton Municipal Airport.
A 10 inch diameter tree branch was split. The early morning storm damage time was estimated from radar.
A large cottonwood tree around three feet in diameter was snapped off about halfway up, with the top laying on a the roof of a house near the Camanche Marina. The early morning storm damage time was estimated from radar.
Deep Creek west of Preston was out of its banks, flowing over 17th St and closing the road.
Farmer's Creek was out of its banks, flowing over 175th Ave and closing the road.
Hail was reported to be a mix of pea to quarter size.
Urban street flooding was reported along Grande Avenue.
No tree damage was reported.
The hail was mostly penny size, with a few the size of nickels.
The public estimated 70 mph winds with quarter size hail.
This report was relayed to the NWS by the Benton County emergency manager.
Tree limbs were blown down in Watkins. The storm damage time was estimated from radar.
An EF-1 tornado touched down southeast of Winthrop, Iowa. A house was damaged and the garage door failed, which allowed the roof to come off. Nearby tree damage was also surveyed.
Widespread flash flooding began in Buchanan county near Independence, with low lying areas flooded and some road closures on the east side of Independence. Flooding of gravel roads was reported about 1030 PM, 3 miles south of the Winthrop Golf Course. At 1128 PM, flash flooding caused multiple road closures in northern Buchanan county.
Spotters estimated 64 mph winds.
Multiple trees were snapped off about halfway up on the trunk along Highway 13 north of Manchester. The time was estimated from radar.
Local broadcast media relayed a public report of winds around 70 mph.
Water was about one foot deep over the road on the north side of Manchester. The water was over the curbs of the road, and into the grass.
A tree limb was down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2018Every state in 2018This day in weather historyThe tornado archive for Iowa, 2018Warnings in Iowa, June 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 750789, 755984, 755976, 755980, 750790, 755958, 755959, 755960, 750791, 755961, 768811, 755962, 755985, 755963, 755964, 755965, 755986, 755966, 755981, 755968, 768816, 755987, 755988, 755982, 755989, 768820, 755983.