Widespread showers and thunderstorms moved across eastern Iowa ahead of a cold front during the afternoon and evening of August 16th. These storms produced rainfall of 1 to 3 inches.
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.
Widespread showers and thunderstorms moved across eastern Iowa ahead of a cold front during the afternoon and evening of August 16th. These storms produced rainfall of 1 to 3 inches. One thunderstorm produced a brief tornado in Jones County.
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 Aug 16, 2:31 PM CST, 2 hours 37 minutes earlier.
Area Forecast Discussion National Weather Service Quad Cities IA IL 331 PM CDT Thu Aug 16 2018 .SYNOPSIS... Issued at 330 PM CDT Thu Aug 16 2018 Current water vapor loop was indicating the main upper low center starting to roll east of the Sioux Falls area, with eyes set on southeastern IA by midnight. Increasing lift off this system as it approaches central IA, and diurnal heating between the clouds producing an uptick in sctrd shower/thunderstorm activity locally. The upper level trof will continue to produce sctrd precip acrs portions of the area through Friday, before a dry and seasonable weekend will be in store between systems. Then a potentially significant wave and weather maker still indicated by the latest medium range models to roll through the region by early next week. && .SHORT TERM...(This Evening through Friday) ISSUED AT 330 PM CDT Thu Aug 16 2018 Tonight...As mentioned above, the approaching upper low will continue to keep sctrd showers and storms going well into the night, before the upper low opens up and along with a nocturnal/diurnal decrease, expect a wane into early Friday morning. CAPEs have grown to 2000 to 3000 J/KG, and then range from 1500 to 2500 well into the evening. This combined with increasing deeper layer shear as the wave arrives, may keep the threat for stronger storms going through at least 8 PM CDT. With PWAT's of 1.7 to 1.8 inches still hanging on acrs the area, locally heavy rainfall and lightning strikes the primary threats with evening storms. But a more vigorous updraft in a stronger storm may eventually lead to a precip-loaded microburst of wind. Instability, elevated shear and low LCL's may also keep the chance for funnel clouds going through at least early evening. The prime forcing in diffluent cyclonic flow aloft off the propagating upper trof will look to shift acrs eastern KS and the southern 2/3's of MO tonight, so the local activity secondary. But the MO forcing may allow for more sctrd storms increasing from mid evening through 3 AM acrs the far southern CWA. Light sfc winds in ongoing saturated low level's may once again combine to produce patchy to areas of fog late tonight and into early Friday morning, but with the low pressure overhead and potential for more clouds hanging on, low confidence on fog coverage and extent of density to issue any kind of product at this point. Friday...Another day of a precip minimal window in the morning, with lingering fog and low stratocu lifting diurnally into a partly to mostly cloudy deck by afternoon. Lingering lift off the trof axis aloft will help induce more isolated to sctrd showers and storms by Friday afternoon, but more of the coverage to occur to the east of the MS RVR and even east of the DVN CWA. More of a north to northeast sfc wind increasing to 5-10 MPH will help mix out any morning fog or haze, and combine with cloud breaks to warm us back up into the low ti mod 80s Friday afternoon. Sfc DPTs still advertised by the models to maintain around 70, but some chance northeast breeze could help reduce them down into the mid to upper 60s. ..12.. .LONG TERM...(Friday Night through next Thursday) ISSUED AT 330 PM CDT Thu Aug 16 2018 The main focus in the extended is a seasonally strong system slated for Sunday night through Monday, with the potential for decent rainfall of a half inch to an inch and a half. Quiet weather is expected Friday night through Sunday, with high pressure over the region resulting in mostly clear/sunny skies, light/calm winds, and seasonal temps. Areas that receive decent rains prior to Friday night; as well as typical low lying areas and river valleys; may experience some patchy fog late Friday night into Saturday morning. It is too early to introduce into the public forecast at this time, but this will need to be reevaluated for future forecast issuances/updates. Models have come into better agreement with track of surface low Sunday evening into Tuesday; taking it on a more southern track; roughly on a WSW to ENE path across northeast Missouri. Precipitation chances are introduced into western third of CWA as early as Sunday evening with 40 to 70 POPs across much of the CWA through Monday. It is still too early to determine whether or not there will be any severe weather threats. Cooler temps are expected Monday, with highs possibly struggling to reach the mid 70s to near 80. Cool and breezy conditions are expected Tuesday with a lingering slight chance of showers possible across the southeast two thirds. Highs Tuesday and Wednesday will be in the mid 70s to near 80, warming slightly by Thursday with upper 70s to low 80s forecast. Good nights for sleeping are expected after Tuesday, with low humidity levels and cool overnight lows mainly in the mid 50s to near 60. 14 && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) ISSUED AT 1245 PM CDT Thu Aug 16 2018 Mainly MVFR level BKN coverage cumulus clouds this afternoon with increasing amounts of sctrd showers and thunderstorms developing in the VCNTY of most TAF sites. As an upper level system approaches, these showers and storms will continue in a hit and miss fashion through late evening before some coverage decrease will occur into the early Friday morning hours. The exception may be at BRL where sctrd showers and thunderstorms may continue through 3 or 4 AM especially to the south of that site. Otherwise, light and variable winds in ongoing high humidity sfc layer may foster more fog development later tonight and into Friday morning, before increasing north to northeast winds brings VSBY improvements as the morning progresses. ..12.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && SYNOPSIS...12 SHORT TERM...12 LONG TERM...14 AVIATION...12
Hazardous Weather Outlook National Weather Service Quad Cities IA IL 1143 AM CDT Thu Aug 16 2018 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-171000- 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- 1143 AM CDT Thu Aug 16 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...THIS AFTERNOON AND TONIGHT Scattered thunderstorms are expected to develop across the area this afternoon and evening. The primary threats will be lightning and locally heavy rainfall. But a few strong to severe storms capable of damaging winds will also be possible. The Storm Prediction Center has a marginal risk of severe storms for areas generally along and south of the Highway 20 corridor. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY On Monday, a seasonally strong storm system will bring thunderstorms to the outlook area. It is too early to assess any severe or heavy rain risk at this time. Interested individuals should monitor this product for further updates. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed this afternoon and evening. 12
Special Weather Statement National Weather Service Quad Cities IA IL 118 PM CDT Thu Aug 16 2018 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-162030- 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- Including the cities of Independence, Manchester, Dubuque, Vinton, Cedar Rapids, Anamosa, Maquoketa, Marengo, Iowa City, Tipton, Clinton, Muscatine, Davenport, Bettendorf, Sigourney, Washington, Wapello, Fairfield, Mount Pleasant, Burlington, Keosauqua, Fort Madison, Galena, Freeport, Mount Carroll, Sterling, Moline, Rock Island, Geneseo, Princeton, Hennepin, Aledo, Oquawka, Monmouth, Carthage, Macomb, Memphis, and Kahoka 118 PM CDT Thu Aug 16 2018 ...Scattered Showers and Thunderstorms Capable of Producing Funnel Clouds This Afternoon... At 116 PM CDT...scattered showers and isolated thunderstorms continued to develop and increase across the area. At 110 pm, a trained spotter reported a brief funnel cloud about 6 miles east of Tipton, Iowa in Cedar County. Funnel clouds of this nature are short lived and rarely touch the ground. However, if you notice one approaching the ground, move indoors to a place of safety. The National Weather Service will continue to closely monitor the situation. Please forward reports of funnel cloud sightings to the nearest law enforcement agency for relay to the National Weather Service. RP Kinney
Special Weather Statement
National Weather Service Quad Cities IA/IL
343 PM CDT THU AUG 16 2018
IAC061-162215-
Dubuque-
343 PM CDT THU AUG 16 2018
...A THUNDERSTORM PRODUCING HEAVY RAIN WILL AFFECT NORTHWESTERN
DUBUQUE COUNTY UNTIL 515 PM CDT...
At 343 PM CDT, radar indicated a thunderstorm with heavy rain was
located over Durango, or near Dubuque. The thunderstorm with heavy
rain is nearly stationary.
Minor flooding of area creeks and streams is possible.
Rainfall amounts of one to two inches have fallen across the area.
Additional rainfall amounts of up to one inch are possible.
Minor flooding is possible. If you are driving and encounter a
flooded roadway, Turn around, don't drown. Most flood deaths occur in
vehicles.
LAT...LON 4264 9072 4263 9070 4259 9069 4257 9066
4254 9064 4251 9064 4249 9066 4248 9066
4247 9064 4244 9088 4256 9101 4266 9081
TIME...MOT...LOC 2043Z 245DEG 2KT 4255 9077
GibbsSpecial Weather Statement National Weather Service Quad Cities IA/IL 356 PM CDT THU AUG 16 2018 IAC101-162215- Jefferson- 356 PM CDT THU AUG 16 2018 ...A STRONG THUNDERSTORM WILL AFFECT JEFFERSON COUNTY UNTIL 515 PM CDT... At 356 PM CDT, a strong thunderstorm was located near Batavia, or 10 miles east of Ottumwa, moving east at 25 mph. Winds in excess of 40 mph and half inch hail are possible with this storm. Locations impacted include... Fairfield, Batavia, Libertyville, Lockridge, Maharishi Vedic City, Pleasant Plain, Abingdon, Fairfield Municipal Airport, Perlee, East Pleasant Plain, Glasgow, Germanville, Jefferson County Fairgrounds, Jefferson County Park, Brookville, Mac Coon Access, Salina, Collett, Round Prairie Park and Beckwith. 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. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. Persons in campgrounds should consider seeking sturdy shelter until this storm passes. LAT...LON 4112 9218 4115 9172 4090 9172 4090 9218 TIME...MOT...LOC 2056Z 269DEG 21KT 4101 9222 Gibbs
Special Weather Statement
National Weather Service Quad Cities IA/IL
403 PM CDT THU AUG 16 2018
IAC019-162300-
Buchanan-
403 PM CDT THU AUG 16 2018
...A THUNDERSTORM PRODUCING HEAVY RAIN WILL AFFECT BUCHANAN COUNTY
UNTIL 600 PM CDT...
At 402 PM CDT, radar indicated a thunderstorm with heavy rain was
located near Independence. The thunderstorm with heavy rain is nearly
stationary.
Minor flooding of area creeks and streams is possible.
Rainfall amounts up to one inch have fallen across the area.
Additional rainfall amounts of 1 to 2 inches are possible.
Minor flooding is possible. If you are driving and encounter a
flooded roadway, Turn around, don't drown. Most flood deaths occur in
vehicles.
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.
Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.
LAT...LON 4233 9160 4236 9206 4247 9206 4247 9208
4264 9208 4264 9161
TIME...MOT...LOC 2102Z 278DEG 1KT 4252 9186
GibbsSpecial Weather Statement National Weather Service Quad Cities IA/IL 406 PM CDT THU AUG 16 2018 IAC177-162200- Van Buren- 406 PM CDT THU AUG 16 2018 ...A STRONG THUNDERSTORM WILL AFFECT NORTHERN VAN BUREN COUNTY UNTIL 500 PM CDT... At 406 PM CDT, a strong thunderstorm was located near Batavia, or 12 miles southwest of Fairfield, moving east at 30 mph. Wind gusts up to 50 mph and nickel size hail are possible with this storm. Locations impacted include... Birmingham, Stockport, Douds, Leando, Bentonsport/Vernon, Morris Park, Mount Zion, Utica, Kilbourn and Selma. 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. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. Persons in campgrounds should consider seeking sturdy shelter until this storm passes. LAT...LON 4090 9172 4070 9172 4082 9218 4090 9218 TIME...MOT...LOC 2106Z 286DEG 24KT 4093 9220 Gibbs
Special Weather Statement
National Weather Service Quad Cities IA/IL
533 PM CDT THU AUG 16 2018
ILC085-IAC055-061-170030-
Jo Daviess-Dubuque-Delaware-
533 PM CDT THU AUG 16 2018
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT JO DAVIESS...DUBUQUE
AND NORTHEASTERN DELAWARE COUNTIES UNTIL 730 PM CDT...
At 533 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near Greeley to near Peosta to near
Schapville. The storms are nearly stationary.
Winds in excess of 30 mph and pea size hail are possible with these
storms.
Locations impacted include...
Dubuque, Galena, Asbury, Dyersville, Stockton, Epworth, East Dubuque,
Farley, Warren, Peosta, Edgewood, Earlville, Elizabeth, Woodbine, New
Vienna, Colesburg, Worthington, Scales Mound, Holy Cross and Apple
River.
Rainfall amounts of 1 to 2 inches have fallen across the area.
Additional rainfall amounts of up to one inch are possible.
Minor flooding is possible. If you are driving and encounter a
flooded roadway, Turn around, don't drown. Most flood deaths occur in
vehicles.
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.
Persons in campgrounds should consider seeking sturdy shelter until
these storms pass.
LAT...LON 4252 9066 4251 9064 4251 8993 4231 8992
4230 9042 4231 9042 4238 9047 4238 9066
4230 9067 4230 9097 4264 9158 4265 9112
TIME...MOT...LOC 2233Z 226DEG 2KT 4262 9131 4242 9079 4242 9028
GibbsThe Quad Cities radar (KDVN), 52 km away, was scanning. The volume nearest the first event began at 23:08 UTC.
1 tornado. Local standard time, as filed.
Six firefighters observed a tornado touch down on the west side of Oxford Junction, Iowa. There was damage to a pipe and a shingles on a structure. The peak estimated winds were 75 MPH.
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, August 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: 781535.