Many river basins went into flood as heavy rain fell across much of the area through the month of September. By late September the Iowa River at Tama also went into flood.
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.
Many river basins went into flood as heavy rain fell across much of the area through the month of September. By late September the Iowa River at Tama also went into flood.
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 Sep 26, 2:40 PM CST, 1 hour 20 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 340 PM CDT Wed Sep 26 2018 .DISCUSSION.../Tonight through Wednesday/ Issued at 340 PM CDT Wed Sep 26 2018 The primary themes for Iowa weather through the middle of next week will be cooler temperatures heading into the weekend, with frost possible north, and then a return to a somewhat more active pattern next week with moderating temperatures and moisture as well as convection. At onset, our current central CONUS mean trough will remain in place and be reinforced as the late afternoon Manitoba short wave as it moves into the Great Lakes early Thursday. This will allow temps to warm somewhat tomorrow, but its associated frontal passage by afternoon will usher in the coolest air of the season to end the week. This will also drop the primary baroclinic zone into the MO Valley with this weak thermodynamic forcing and kinematic forcing on the nose of the jet through the long wave trough re-introducing low end PoPs north to south late Thursday through Friday. Any amounts will be on the light side with soundings showing much of the moisture 2.5km and above and only just approaching saturation below. Heading into the weekend, temperatures and frost potential north will be the primary concern. Skies should clear by Friday Night traversing the Upper MS Valley. This will allow for good radiational cooling conditions with light winds, and with dewpoints just below freezing and overnight lows approaching the freezing mark, frost appears likely north of Highway 20. This will only last one night however with temperatures rebounding into the weekend as the high exits. Heading into the weekend and next week the forecast will be broad- brushed, especially late, with details difficult to come by. Our pattern will become more zonal with upper level ridging building through the southern Plains. Confidence is low however with the models having to deal with the large current eastern Pacific low near 33W 136N as it eventually gets absorbed into the westerlies, wide uncertainties regarding the speed and strength of TS Rosa remnants and another iteration of an upper low off the CA coast. There is some agreement early with strong warm/theta-e advection lifting through this weekend and early next week resulting in intermittent precip chances with the warm front somewhere through the state. Another concern will be peak heating Sunday. Although surface based convection may be hard to come by due to CINH considerations, deep shear along the warm front during peak heating Sunday will need to be watched for at least some degree of severe and tornado potential. Into next week any of the GFS, FV3, ECMWF and CMC solutions suggest broad SW flow through the Plains into IA, but short wave timing and resultant surface reflections result in poor confidence by Tuesday with the frontal boundary anywhere from the MO to MN border which could of course have considerable temp, moisture and convection impacts. Thus the general theme during this period will be some degree of warmth and humidity return with precip and convection intensity and severe potential yet to be determined. && .AVIATION.../For the 18Z TAFS through 18Z Thursday afternoon/ Issued at 1233 PM CDT Wed Sep 26 2018 Confidence is high in VFR conditions through the period with diurnal cumulus northeast this afternoon and increasing mid cloudiness north by Thursday morning. LLWS may also develop overnight north and west /KFOD/KMCW/ as low level SW winds increase as current KS surface high eventually moves away. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && DISCUSSION...Small AVIATION...Small
Hazardous Weather Outlook National Weather Service Des Moines IA 352 PM CDT Wed Sep 26 2018 IAZ004>007-015>017-023>028-033>039-050-271100- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun- Webster-Hamilton-Hardin-Grundy-Black Hawk-Tama- 352 PM CDT Wed Sep 26 2018 This Hazardous Weather Outlook is for portions of central and northern Iowa. .DAY ONE...This afternoon and tonight River flood warnings remain in effect for portions of the area. Please refer to the National Weather Service website for more details, weather.gov/desmoines. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Frost will be possible north early Saturday morning. Those with susceptible vegetation should monitor the forecast for updates and potential advisories later this week. Thunderstorms return to the forecast early next week. The severe weather threat is low for Sunday and Monday, but is more uncertain for Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated. IAZ044>049-057>062-070>075-081>086-092>097-271100- Crawford-Carroll-Greene-Boone-Story-Marshall-Audubon-Guthrie- Dallas-Polk-Jasper-Poweshiek-Cass-Adair-Madison-Warren-Marion- Mahaska-Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold- Decatur-Wayne-Appanoose-Davis- 352 PM CDT Wed Sep 26 2018 This Hazardous Weather Outlook is for portions of central and southern Iowa. .DAY ONE...This afternoon and tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Thunderstorms return to the forecast early next week. The severe weather threat will be better determined in the coming days. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated through at least the rest of the week. Small
The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
The Iowa River at Tama Highway E49 crested at 12.82 feet on 28 September 2018 at 1315 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, September 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: 785706.