Persistent below normal precipitation along with above normal temperatures during June led to the expansion of severe drought across much of northern and central Iowa. Stream-flows fell to well below normal in these areas with stress to crops developing.
Every event with a place to put it; 24 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Persistent below normal precipitation along with above normal temperatures during June led to the expansion of severe drought across much of northern and central Iowa. Stream-flows fell to well below normal in these areas with stress to crops developing.
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 15, 5:22 AM CST, 1 hour 38 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 622 AM CDT Tue Jun 15 2021 .DISCUSSION.../Today through Monday/ Issued at 420 AM CDT Tue Jun 15 2021 Forecast highlights: -Very warm to hot temperatures through Thursday then some cooling into the weekend. -Becoming more active with convective threats Wednesday night into Friday morning and again Sunday/Sunday night. Currently, light surface flow across the state as ridge axis slowly passes through Iowa. The airmass is remaining relatively dry for mid- June allowing for decent diurnal ranges of 30 degrees or more with the trend persisting into Thursday. Today will be similar to Monday although a degree or two cooler with weak cold advection persisting. However, the cold advection continues to be offset by ample insolation and a dry airmass that allow for efficient heating. This remains the case into Wednesday although the increasing warm advection should help push temperatures warmer than today. There is also a push of moisture back into the state late Wednesday into Wednesday night with modest theta-e advection. Some isolated to scattered convection remains possible on Wednesday night as this advection passes through the state. However, the GFS solution seems a bit to robust compared with other output and is a high end outlier for coverage and QPF. Have generally paired back toward a consensus of more isolated coverage and lighter QPF on Wednesday night. Thursday will see the thermal ridge passing into the state with the warmest day of the forecast period. Temperatures climbing well into the 90s are expected across much of the forecast area with southwest surface winds ahead of an approaching boundary. With the relatively dry conditions are decent mixing, readings climbing to between 95 and 100 are expected across the southwest 2/3rds of the forecast area. The limiting factor in heat headlines is expected to be dewpoints dropping into the lower 60s by afternoon with heat index values topping out around 100 in the southwest. Consensus on models is for convection to develop by early afternoon in southern MN to northern IA as increased forcing and approaching front helps to erode cap and force parcel to the LFC. Rather robust MUCapes are anticipated across the state by afternoon upwards of 2000-2500 J/KG in the warm sector. The mixing creates somewhat of an inverted-V sounding in most locations by afternoon with damaging winds and large hail the primary concerns for the event and a slight risk is out in portions of the forecast area. However, should an outflow boundary from Wednesday overnight/early Thursday morning convection be in place across the area, this may help to provide a more favorable environment for a tornado or two. However, predicting these is difficult and chancy at best. The convection continues southeast into Thursday night with the eastern half of the forecast area most likely to see convection. Some residual threat persist into the south on Friday although cold advection increases during the day with increasing subsidence. Farther out, Saturday appears quiet and cooler with ridging across the state. Another shortwave drops southeast into the northern Plains by Saturday night into Sunday. Warm advection quickly returns on Saturday night into Sunday ahead of a rapidly approaching surface wave. Both Euro and GFS develop convection early Sunday near the Missouri River Valley and into Iowa with the strong theta-e advection. Additional convection is expected during the day as the surface wave moves across the state with robust mid-level kinematics. A break is expected into early next week but a flattening flow with Iowa on the southern edge of the WNW to W flow aloft by midweek hints at a more active pattern. && .AVIATION.../For the 12Z TAFS through 12Z Wednesday morning/ Issued at 622 AM CDT Tue Jun 15 2021 Aviation weather remains good for entire forecast with unrestricted visibility and ceilings. Winds from the north to northeast and light today becoming light from the east southeast by the end of the period. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && DISCUSSION...Cogil AVIATION...Cogil
Hazardous Weather Outlook National Weather Service Des Moines IA 236 AM CDT Tue Jun 15 2021 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-160745- 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- 236 AM CDT Tue Jun 15 2021 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Wednesday through Sunday Thunderstorm chances return to the forecast Wednesday night into Thursday night. A few storms may be strong to severe with hail and gusty winds, but widespread severe weather is not expected at this time. Additional storms are possible early next week. The threat for severe weather is uncertain. .SPOTTER INFORMATION STATEMENT... Spotters will not be needed before Wednesday night.
The national radar mosaic for the moment the first event began.
24 drought. Local standard time, as filed.
Severe drought developed across Winnebago County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Worth County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Hancock County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Cerro Gordo County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Wright County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Franklin County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Butler County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Bremer County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Sac County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Calhoun County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Webster County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Hamilton County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Hardin County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Grundy County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Carroll County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Greene County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Boone County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across Story County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Marshall County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Audubon County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Guthrie County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Dallas County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across much of Polk County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
Severe drought developed across a small portion of northern Madison County by mid-June. Below normal precipitation combined with above normal temperatures depleted ground water and diminished streamflow. Stress to crops began to develop as well.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2021Every state in 2021This day in weather historyWarnings in Iowa, June 2021
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: 957647, 957648, 957649, 957650, 957651, 957653, 957654, 957655, 957656, 957657, 957658, 957659, 957660, 957661, 957662, 957663, 957664, 957665, 957666, 957667, 957668, 957669, 957670, 957671.