A warm front moved across the area late on the evening of April 21 into April 22. 5 inches allowed for a band of heavier precipitation to set up over a narrow corridor in central Iowa.
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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.
A warm front moved across the area late on the evening of April 21 into April 22. While thunderstorms remained below severe criteria, deep saturation and precipitable water values over 1.5 inches allowed for a band of heavier precipitation to set up over a narrow corridor in central Iowa. Several locations received over 3 inches of rain and a few areas saw flash flooding within towns, resulting in brief road closures. Rain ended by 11 am across the affected area.
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 Apr 21, 5:42 PM CST, 2 hours 18 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 642 PM CDT Thu Apr 21 2022 ...Updated for the 00z Aviation Discussion... .DISCUSSION.../Tonight through Thursday/ Issued at 238 PM CDT Thu Apr 21 2022 Key Messages: - Active few days ahead with periodic threats of heavy rainfall, strong to severe storms, and gusty winds. At 20z GOES water vapory imagery depicted a pseudo-zonal pattern over the much of the conus as the mean flow aloft undergoes a transition, switching to mean troughing out west and ridging to the east. Our local region has been left under a weaker flow regime especially near the surface, where stubborn fog/stratus has been slow to clear out along and south of a diffuse and nearly stationary surface boundary. Satellite imagery has shown further erosion of any low cloud cover over the last hour, and temperatures have been quick to rebound once sunshine takes over. Thus afternoon forecast highs in the 60s for much of the area still appears well on track. Surface low over eastern Colorado steadily deepens this evening into the overnight in response to a trough carving out over the western conus. Increasing LLJ and isentropic ascent will promote convective development along and north of a warm frontal boundary stretched over KS/MO. Models bring storms into southwest Iowa between 00z-03z, then spreading north and east thereafter into the overnight hours. Soundings suggest storms will be highly elevated as they cross into Iowa, but may still pose a threat for marginally severe hail central and south as MUCAPE of 500-1000 J/kg and ample deep layer shear may support a few organized updrafts late this evening. Any hail threat should diminish as the environment transitions to more of a heavy rain threat as pwats steadily increase to near 1.25-1.50" and soundings become more moist adiabatic with narrow CAPE profiles that favor efficient rainfall rates. Hi-res models gradually develop a cold pool and anchor convection to it as the complex backbuilds into the steady stream of deep moisture transport within the LLJ. Northerly Corfidi vectors 10-20 kts suggest the cold pool may even sag a bit south into the low level flow. Bulk of the hi-res model suite has latched on to this idea and thus boosts confidence in a swath of heavier QPF possibly exceeding 2-3"+, however the location remains much more uncertain. HREF LPMM QPF paints of swath of 2"+ near and just south of I-80, which seems like a reasonable middle ground as high-res guidance waffles between central and southern Iowa. The ceiling on max precip amounts may hinge on if the cold pool is progressive and drags convection south, or if the convection remains anchored with heavy rainfall over the same areas for a prolonged period. Either way we will need to closely monitor for possible heavy rain impacts late tonight into Friday morning. Southerly flow cranks up Friday as leeside cyclogenesis continues over the high Plains. Winds pick up with gusts of 20-30 mph common through the day. Convective trends overnight casts considerable uncertainty for precip trends Friday as models poorly resolve northward progression of the warm front, likely due to possible augmentation of the boundary by early day convection. Progressive solutions push the front and any convection north into MN by the afternoon, but any slower push may keep some showers/storm around later into the day. Once the front clears it will feel rather humid as surface dewpoints push into the mid 60s. Highs hinge on the extent of remnant cloud debris, but generally kept in line with the previous forecast that pushed highs into the 70s, possibly low 80s into southwest IA. A stout EML should effectively squash any potential for thunderstorm activity once the warm front has passed. Windy conditions along with another window for thunderstorms Saturday as the main upper low ejects northeast toward the northern Plains. Model soundings show 35-45 kts near the top of the mixed layer and within a very compressed surface pressure field. Saturday looks like a strong candidate for a wind advisory especially north/west. Models try to develop convection early in the day as deep kinematic ascent overspreads the warm sector. This convection would likely be elevated as a stout low level cap will be difficult to overcome for surface based parcels, but any early day convection may still pose a threat for small hail. More widespread convection likely holds off until later in the day into Saturday night along a surging cold front. The severe potential with this activity is uncertain due to the aforementioned possible warm sector contamination from previous convection that would limit instability. Shear vectors are also parallel to the frontal axis and may be unfavorable for strong, discrete updraft organization. Dry and cooler conditions follow again in the wake of the departing upper low. Highs start the week in the 40s and 50s then make a steady rebound by mid-week as lower amplitude upper ridging builds overhead. Models track some weaker waves through the flow and bring along some spurious precip chances, but confidence is quite low at that time range as models exhibit considerable timing and moisture differences. && .AVIATION.../For the 00Z TAFS through 00Z Friday evening/ Issued at 638 PM CDT Thu Apr 21 2022 Current VFR conditions will give way to another round of MVFR and IFR as showers and storms develop and overspread the region for a number of hours overnight. All TAF sites will be affected, initially affecting sites KDSM/KOTM, then spreading north and eastward overnight. Initial activity this evening will be more sporadic, giving way to widespread showers and storms around/after 06z and lasting into/around 15z before exiting eastward. Cannot rule out possibility of LIFR ceilings, but kept prevailing IFR with limited confidence. Gusts into the 20s kts out of the ESE/SE through much of the period as well. VFR conditions will begin to return late in the period. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && DISCUSSION...Martin AVIATION...Curtis
Hazardous Weather Outlook National Weather Service Des Moines IA 344 PM CDT Thu Apr 21 2022 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-222045- 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- 344 PM CDT Thu Apr 21 2022 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight Rain showers and thunderstorms will enter the area late this evening and continue overnight. Heavy rainfall is possible. There is a marginal risk for severe storms south of Highway 20. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Rain showers and thunderstorms from Thursday Night will continue into Friday morning. A few storms may be severe, mainly south of Highway 20. Rain showers and thunderstorms will develop Friday afternoon and evening. There is a marginal risk for severe storms, with a slight risk in far western portions of the area. Thunderstorms may be capable of producing hail and damaging wind. In addition, heavy rainfall may lead to localized flooding, and elevated river levels. Rain showers and thunderstorms are expected on Saturday. There is slight risk for severe storms on Saturday across much of the area. Hail and damaging winds will be the main threats on Saturday, though a tornado threat cannot be ruled out. Areas that experienced heavy rainfall on Friday will be at increased risk for flooding with additional rainfall on Saturday. .SPOTTER INFORMATION STATEMENT... Spotter reports will likely be needed over the next few days. Krull
The Des Moines radar (KDMX), 21 km away, was scanning. The volume nearest the first event began at 02:00 UTC.
10 heavy rain, 8 flash flood. Local standard time, as filed.
Northwest of Huxley report of 3.5 inches of storm total rainfall since 10pm. Public report via social media.
Storm total of 3.12 inches of rain. Rain occurring at observation.
Storm total of 2.98 inches of rain. Light rain continues.
Storm total of 3.09 inches of rain. Rain continues.
Storm total of 3.41 inches of rain. Rain continues.
Storm total of 3.06 inches of rain.
Storm total of 3.69 inches of rain.
Storm total of 3.80 inches of rain.
Storm total of 3.03 inches of rain. Light rain continues.
Storm total of 3.90 inches of rain.
Several streets closed in Jamaica and Bagley due to surface flooding. Relayed by the Emergency Manager.
Social media picture of flash flooding in Huxley. water up to 10 inches deep with a stalled vehicle in town.
Minor street flash flooding relayed through trained spotter.
Water from Four Mile Creek over the road along 510th Ave south of Slater.
Standing water in the 1600 block of SE Cortina Drive. Relayed through law enforcement twitter.
Emergency manager relayed a report from a trained spotter of localized street flooding in Woodward and Bouton with possible power outages.
Flash flooding near four Mile Creek north of Briarwood Golf Course. Picture via social media from trained spotter.
Standing water of unknown depth reported by local media on South 2nd street north of old highway 30. relayed via social media.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2022Every state in 2022This day in weather historyWarnings in Iowa, April 2022
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: 1024208, 1024198, 1024199, 1024200, 1024201, 1024204, 1024207, 1024210, 1024211, 1024212, 1024184, 1024187, 1024188, 1024197, 1024191, 1024192, 1024194, 1024196.