River levels remained high along the West Fork of the Des Moines River at Estherville and additional heavy rain toward the middle to end of May led to the river going back into flood.
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The episode as NWS DMX wrote it up.
River levels remained high along the West Fork of the Des Moines River at Estherville and additional heavy rain toward the middle to end of May led to the river going back 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 May 24, 5:29 AM CST, 4 hours 31 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 629 AM CDT Thu May 24 2018 ...Updated for 12z Aviation Discussion... .SHORT TERM.../Today through Tonight/ Issued at 325 AM CDT Thu May 24 2018 8z GOES-East Nighttime Microphysics shows high clouds streaming into Iowa while convective, colder IR cloud tops remain over north central Nebraska into central South Dakota. Radar trends have shown the convection west of us weakening and most CAMs show this dissipating or staying northwest of our forecast area. Some of the CAMs glance western Iowa with a few developing showers or storms this morning, but forcing is weak with a greater chance for thunderstorms later in the afternoon into tonight. Before then, it will be another hot day as there is little change in the way of 850mb temperatures from Wednesday afternoon to Thursday afternoon. This will translate to highs in the middle to upper 80s, which is at least 10 degrees above normal across central Iowa. As q-vector convergence begins to arrive late in the afternoon, will see showers and storms develop over central Minnesota into northwest and western Iowa. This area will have MLCAPEs between 1500 and 2000 J/kg. However, deep layer shear and mid-level lapse rates will be weak to modest at best with these parameters better west of our forecast area. So isolated severe hail and damaging wind gusts will be the concerns. As for heavy rainfall threat within 850-300mb flow of 15 to 20 knots, precipitable water values will be around 1.5 inches, which is in the 175% of normal. Further, the NAEFS has specific humidities in the 99th percentile. This could certainly lead to some locally heavy rainfall, but don't see a widespread flash flood risk at this point. By Friday morning, the showers and storms will be pushing east from central Iowa into eastern Iowa. .LONG TERM.../Friday through Wednesday/ Issued at 325 AM CDT Thu May 24 2018 Mean ridging across the central United States will be the big forecast driver over the next several days. That being said, the beginning of the longer term on Friday morning will see a weakness in the upper ridging with a shortwave passing across the upper Midwest. Isolated to scattered convection will linger into Friday morning across central Iowa as the low level jet veers into the state but will be decreasing in coverage and intensity with weakening moisture transport. The bulk of forcing with the shortwave will remain well north of Iowa with the boundary washing out across the state late Friday into early Saturday. However, sufficient convergence along the weakening boundary should produce some scattered convection in the weakly capped environment on Friday afternoon/evening over the southeast half of the forecast area. Shear will be paltry although strong CAPE sufficient of large hail production may briefly lead to an isolated severe storm or two. A strong downburst may also occur with the heavy rain cores as well. This convection should weaken quickly into Friday evening with stabilization of the boundary layer after sunset as dynamic forcing will be nearly nil. The holiday weekend is shaping up to be quite hot with upper ridging re-establishing itself in the region in the wake of the shortwave. Thermal ridging in the Plains will extend eastward into the state and with generally sunny conditions, temperatures into the lower 90s seem likely on Saturday through Monday and possibly Tuesday. Dewpoints are expected to remain mainly in the mid 60s which should keep heat indicies below 100 but still unseasonably warm for this time of year. Will likely highlight the expected heat in a Situation Report and HWO with no headlines expected, especially given overnight lows dropping into the upper 60s to around 70 which does give some break to the daytime heat. The GFS does continue its proclivity towards more widespread convection through the weekend into early next week despite weak to nil forcing and prefer the Euro which keeps the bulk of convection associated with deeper forcing toward later Tuesday and into the middle of next week. Of additional concern, will be continuing to monitor the dry conditions in south central/southeast Iowa as rainfall deficits continue to mount. Many of these locations have seen significant deficits since 2016 and the early growing season amounts so far this year in these location remain below normal. && .AVIATION.../For the 12Z TAFS through 12Z Friday morning/ Issued at 629 AM CDT Thu May 24 2018 Primary concern will be scattered thunderstorms expected to impact the terminals in the latter half of this TAF period. At this point, have continued VFR at all terminals with mention of VCTS at FOD, MCW, and DSM with much uncertainty around timing owing to low confidence. Thunderstorms may impact ALO and OTM late in the period, but not enough confidence to include at this time. Otherwise, winds will become breezy from the south through the day today. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...Ansorge LONG TERM...Cogil AVIATION...Ansorge
Hazardous Weather Outlook National Weather Service Des Moines IA 334 AM CDT Thu May 24 2018 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-251100- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun- Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene- Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper- Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union- Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne- Appanoose-Davis- 334 AM CDT Thu May 24 2018 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight Scattered thunderstorm are expected far west late this afternoon and across much of central Iowa overnight. There is a marginal risk for severe storms during the period with large hail the main threat. Heavy rainfall is also possible which may lead to flash flooding or river flooding. .DAYS TWO THROUGH SEVEN...Friday through Wednesday The threat for thunderstorms continues into Friday. There is a marginal risk for severe storms during the period with large hail the main threat. Heavy rainfall is also possible. The main threat for thunderstorms in the extended are late next Tuesday into Wednesday. The threat for severe weather is low at this time. Iowans will see the first bout of heat and humidity this season from Saturday through Monday. This could lead to heat related impacts if precautions are not taken. .SPOTTER INFORMATION STATEMENT... Brief spotter activation may be needed late today into this evening and again later Friday afternoon into the evening.
The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
The West Fork of the Des Moines River at Estherville crested at 8.42 feet on 25 May 2018 at 17:15 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, May 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: 755400.