Heavy rain continued across portions of the state through the latter portion of June that led to another round of river flooding. Several points along the West Fork of the Des Moines remained in flood into July.
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 DMX wrote it up.
Heavy rain continued across portions of the state through the latter portion of June that led to another round of river flooding. Several points along the West Fork of the Des Moines remained in flood into July.
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 Des Moines, IA wrote its last area forecast discussion before the first event at Jun 20, 11:37 AM CST, 1 hour 23 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1237 PM CDT Wed Jun 20 2018 ...Updated for 18z Aviation Discussion... .SHORT TERM.../Today through Tonight/ Issued at 421 AM CDT Wed Jun 20 2018 Ongoing cluster of storms over northern Iowa are slowly weakening with respect rainfall rates. Dual pol and MRMS still suggest 1-2 inch per hour rates. Earlier in the night, dual pol instantaneous rates range from 3 to 5 inches per hour while MRMS was capped out around 2 inches. This was likely due to MRMS depicting some hail within this line of storms that transitioned northward through Highway 20 corridor. However, MRMS precipitation estimates a decent rain band that ranged from 2-3 inches over southeast Calhoun into southern Webster County. The 20.07z HRRR has the best handle on the radar trends this morning and slowly diminishes the current cluster by around 12z. However, some redevelop looks possible during the remainder of the morning hours over northern Iowa but low confidence with additional flash flooding as coverage seems minimal. The next concern of the forecast period was focused on widespread storms later today into tonight across central to northern Iowa. An area of low looks to develop in the vicinity of NW Missouri, SE Nebraska, NE Kansas, and SW Iowa by around 18z this afternoon. This coupled with a strong 500mb shortwave trough to dig across Nebraska and northern Iowa will ignite storms along a warm front extending from southeast Iowa northwest to the west-central portions of the CWA. The NAM/GFS and the 20.00z HREF look to have a good handle on the situations this afternoon and tonight. A widespread swath of 2 to 2.50" precipitable water values stretch from around Ottuwma northwest through Des Moines/Ames and into the northwest portions of the CWA. Warm layer cloud depths of 4000-4500 meters with moderate to strong moisture transport suggest more efficient rain producers in the aforementioned location. Increased QPF over the area as expecting a swatch of 1.5 to 3 inches from the central portions of the CWA northwest to between Carroll and Estherville. With the HREF depicting amounts over 4 to 5 inches, certainly these types of rainfall amounts will cause some flash flood concerns. Thus, confident in the heavy rain setup (and with the recent rains over the past few days) to issue a Flash Flood Watch this afternoon into Thursday morning. This coincides with Moderate Risk of excessive rainfall via WPC. Lower confidence with any widespread severe storms today into tonight as shear profiles remain weak. Instability tries to increase over southern Iowa this afternoon south of the boundary and certainly cannot rule out some brief elevated hail storms this afternoon into the evening. .LONG TERM.../Thursday through Tuesday/ Issued at 421 AM CDT Wed Jun 20 2018 Upper trough moving through the central Plains today will continue to deepen and close off over the state Thursday into Friday while continuing to wobble around the region. This will allow precipitation chances to continue across the state Thursday into Friday with bands of showers and some thunderstorms expected to rotate through the forecast area. Instability is weaker across the area with the upper trough overhead so went more with some shower wording with more of a slight chance for thunder Thursday into Friday. With the lack of instability the threat for heavy rainfall to wane some for Thursday into Friday. Otherwise the upper trough to push east into the Ohio Valley region by Friday night with another shortwave trough dropping through the state by late Saturday night into Sunday. This could bring another chance for some scattered showers and thunderstorms. A stronger upper level trough to then deepen as it moves east through the region Monday into Wednesday of next week. This system will again bring additional chances for precipitation to the state. Therefore expecting a fairly wet period through the next 7 days. Will have to assess the potential for additional heavy rain threats with the system early next week as any flooding issues from the next 24 hours could be further exacerbated by continued precipitation chances this weekend and again next week. As for temperatures, highs to remain cooler Thursday into Friday with the clouds/precipitation in place and the upper trough rotating over the state with highs mainly in the low to mid 70s, with even a few upper 60s possible Thursday. Temperatures to then warm back to around 80 for Saturday through Monday and then warm back into the 80s toward the middle of next week. && .AVIATION.../For the 18Z TAFS through 18Z Thursday afternoon/ Issued at 1233 PM CDT Wed Jun 20 2018 Very active TAF forecast. Prolonged precip expected at KMCW and possibly KALO. Timing of showers/thunderstorms will be tricky... mainly think showers, but a lightning strike or two possible overnight. Visibility may need to temporarily lowered during periods of higher rainfall rates. Medium to high confidence in low CIGs overnight at KFOD, KMCW, and KALO. Winds will be increasing above 10kts tomorrow afternoon at KMCW and KALO. && .DMX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until 7 PM CDT this evening for IAZ046>048- 057>060-070>072. Flash Flood Watch through Thursday morning for IAZ004-005-015- 016-023>025-033>036-044-045. && SHORT TERM...Podrazik LONG TERM...Beerends AVIATION...Kotenberg
Hazardous Weather Outlook National Weather Service Des Moines IA 1249 PM CDT Wed Jun 20 2018 IAZ004-005-015-016-023>025-033>036-044-045-211800- Emmet-Kossuth-Palo Alto-Hancock-Pocahontas-Humboldt-Wright-Sac- Calhoun-Webster-Hamilton-Crawford-Carroll- 1249 PM CDT Wed Jun 20 2018 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight A Flash Flood Watch is in effect for the area. Please refer to the National Weather Service website at weather.gov/desmoines for further details. Thunderstorms are likely today into tonight. Heavy rainfall is expected. An isolated strong to severe storm will be possible mainly south of Highway 20 this afternoon and evening. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday There is a chance for weak thunderstorms across the area Thursday into Friday. The severe weather threat is minimal. Thunderstorm chances continue off and on through the weekend into early next week. The threat of severe weather will be determined in the coming days. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed today. Reports of any flooding or heavy rainfall are always appreciated. IAZ006-007-017-026>028-037>039-049-050-061-062-073>075-081>086- 092>097-211800- Winnebago-Worth-Cerro Gordo-Franklin-Butler-Bremer-Hardin-Grundy- Black Hawk-Marshall-Tama-Jasper-Poweshiek-Warren-Marion-Mahaska- Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur- Wayne-Appanoose-Davis- 1249 PM CDT Wed Jun 20 2018 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight Thunderstorms are likely today into tonight. Heavy rainfall will be possible with the thunderstorms. An isolated strong to severe storm will be possible mainly south of Highway 20 this afternoon and evening. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday There is a chance for weak thunderstorms across the area Thursday into Friday. The severe weather threat is minimal. Thunderstorm chances continue off and on through the weekend into early next week. The threat of severe weather will be determined in the coming days. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed today. Reports of heavy rainfall are always appreciated. IAZ059-060-211800- Dallas-Polk- 1249 PM CDT Wed Jun 20 2018 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight A Flash Flood Watch and a few River Flood Warnings are in effect for the area. Please refer to the National Weather Service website at weather.gov/desmoines for further details. Thunderstorms are likely today. Heavy rainfall is expected. An isolated strong to severe storm will be possible this afternoon and evening. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday There is a chance for weak thunderstorms across the area Thursday into Friday. The severe weather threat is minimal. Thunderstorm chances continue off and on through the weekend into early next week. The threat of severe weather will be determined in the coming days. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed today. Reports of any flooding or heavy rainfall are always appreciated. IAZ046>048-057-058-070>072-211800- Greene-Boone-Story-Audubon-Guthrie-Cass-Adair-Madison- 1249 PM CDT Wed Jun 20 2018 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight A Flash Flood Watch is in effect for the area this afternoon. Please refer to the National Weather Service website at weather.gov/desmoines for further details. Thunderstorms are likely today. Heavy rainfall is expected. An isolated strong to severe storm will be possible mainly south of Highway 20 this afternoon and evening. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday There is a chance for weak thunderstorms across the area Thursday into Friday. The severe weather threat is minimal. Thunderstorm chances continue off and on through the weekend into early next week. The threat of severe weather will be determined in the coming days. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed later today and tonight. Reports of any flooding or heavy rainfall are always appreciated. Kotenberg
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
146 PM CDT WED JUN 20 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0140 PM HEAVY RAIN 5 S KNOXVILLE 41.25N 93.10W
06/20/2018 E1.00 INCH MARION IA TRAINED SPOTTER
&&
BFPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
157 PM CDT WED JUN 20 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0154 PM FUNNEL CLOUD 3 W ADEL 41.62N 94.09W
06/20/2018 DALLAS IA TRAINED SPOTTER
ROPE FUNNEL AT INTERSECTION OF P57 AND HWY
6.
&&
BFThe national radar mosaic for the moment the first event began.
9 flood. Local standard time, as filed.
The Raccoon River at Perry crested at 18.04 feet on 23 June 2018 at 14:15 UTC.
The Raccoon River at Des Moines Fleur Drive crested at 15.07 feet on 26 June 2018 at 03:45 UTC.
The Des Moines River at SE 6th crested at 26.83 feet on 26 June 2018 at 03:45 UTC.
The Des Moines River at Fort Dodge crested 4 times during the period the river was in flood. It remained in flood into July. The first crest was at 11.24 feet on 21 June 2018 at 07:00 UTC, the second at 12.75 feet on 23 June 2018 at 04:45 UTC, the third at 12.88 feet on 24 June 2018 at 21:15 UTC, and the fourth crest at 20.26 feet on 27 June 2018 at 22:15 UTC.
The West Fork of the Des Moines River at Estherville crested twice through the period of flooding. The river remained in flood into July. The first crest was at 12.67 feet on 22 June 2018 at 08:30 UTC, and the second one was at 13.33 feet on 25 June 2018 at 21:00 UTC.
The East Fork of the Des Moines River at Algona crested twice through the period of flooding. The first crest was 18.69 feet on 22 June 2018 at 22:15 UTC, the second crest was 19.33 feet on 26 June 2018 at 10:45 UTC.
The West Fork of the Des Moines River at Humboldt crested twice through the period of flooding. The river remained in flood into July. The first crest was at 12.35 feet on 24 June 2018 at 23:30 UTC, and the second one was at 12.64 feet on 28 June 2018 at 16:15 UTC.
The West Fork of the Des Moines River at Emmetsburg crested twice through the period of flooding. The river remained in flood into July. The first crest was at 12.55 feet on 24 June 2018 at 01:45 UTC, and the second one was at 13.00 feet on 27 June 2018 at 09:00 UTC.
The Cedar River at Cedar Falls crested at 90.06 feet on 25 June 2018 at 01:15 UTC.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2018Every state in 2018This day in weather historyWarnings 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: 764800, 764794, 764795, 764798, 764797, 764792, 764799, 764796, 764793.