A warm front lifted across Iowa through the afternoon serving as a focus for convection. MUCAPE of 1000-1500 J/kg and strong deep-layer shear were sufficient for storm development in the warm sector.
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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 lifted across Iowa through the afternoon serving as a focus for convection. MUCAPE of 1000-1500 J/kg and strong deep-layer shear were sufficient for storm development in the warm sector. Storms were fast-moving with storm motions of 45 mph, but fortunately, most storms remained below severe criteria.
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 Mar 19, 2:51 PM CST, 1 hour 19 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 351 PM CDT Thu Mar 19 2020 .DISCUSSION.../Tonight through Thursday/ Issued at 351 PM CDT Thu Mar 19 2020 Push of warm advection and moisture transport into the state this morning produced widespread shower and some thunderstorm activity. Areas across northern Iowa saw widespread 1 to 2 inches of rain, mainly along and north of Highway 20. Farther south, the showers were more progressive with less rain. Currently, the warm front extends from near Red Oak to Des Moines and eastward toward Grinnell. Recent satellite and radar indicates the boundary is moving south through western into central Iowa and is near the Des Moines metro area as of 300 pm. Destabilization is rapidly occurring in far southern Iowa with 100mb mixed layer CAPES approaching 1000-1500 j/kg in the far southwest. This destabilization will continue into the late afternoon as insolation increases with clouds diminishing. Low level shear and helicity are sufficient for tornado development although if the storm is along the southward moving boundary, it is likely that the cold air would undercut the surface updraft. However, any storm ahead of the boundary would be in a decent environment for a tornado and a watch is in place for this potential. Storms that do occur north of the boundary are not expected to have much of a tornado threat, but could certainly produce large hail. Otherwise, another round of moderate to locally heavy rain is expected into central Iowa which will likely push rivers toward flood stage in some locations. There may also be a localized risk of flash flooding but it is not expected to be widespread at this time. Farther north, light to moderate rain will persist into the evening as cold air begins to move into the state. A transition from rain to snow is expected to start toward sunset near Estherville with the transition zone shifting southward through the evening. One to two inches of snow is expected across the northern two tiers of Iowa and when combined with the strong winds, will produce a period of poor conditions this evening in the northwest portion of the forecast area where snow amounts will be greatest, therefore the advisory will continue tonight. Elsewhere, the strong northwest winds will strengthen during the night as cold air pours into the state. Precipitation diminishes after midnight as forcing subsides with all rain/snow ending by daybreak on Friday. Strong northwest winds will persist into Friday with much colder temperatures as thermal trof drops into the state. Wind chills below zero are expected in the northwest during the morning with single digits to teens above zero elsewhere. Moderating temperatures are expected into the weekend with some minor threat of precipitation on Sunday. A better threat of precipitation is expected Monday night into Tuesday as a stronger shortwave passes through the region although there are still some differences in the models on the eventual evolution. && .AVIATION.../For the 18Z TAFS through 18Z Friday afternoon/ Issued at 1239 PM CDT Thu Mar 19 2020 Poor aviation conditions will persist through tonight with low ceilings, restricted visibilities and gusty winds. Widespread showers and thunderstorms are expected into this evening with rain changing to snow in the north. Strong northwest winds are forecast to develop tonight and persist into Friday. Ceilings and visibilities will improve to VFR by the end of the period as the system departs. && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 7 PM this evening to 7 AM CDT Friday for IAZ004-005-015-023-033. && DISCUSSION...Cogil AVIATION...Cogil
Hazardous Weather Outlook National Weather Service Des Moines IA 258 PM CDT Thu Mar 19 2020 IAZ025>028-034>039-044>050-057>062-070>075-081>086-092>097-202000- Wright-Franklin-Butler-Bremer-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- 258 PM CDT Thu Mar 19 2020 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This Afternoon and Tonight There is an enhanced risk of severe weather with all modes of severe weather possible. Heavy rainfall may lead to river flooding or even some localized flash flooding. Strong northwest winds are expected tonight into Friday with much colder air. .DAYS TWO THROUGH SEVEN...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is likely across this afternoon and evening. IAZ004-005-015-023-024-033-202000- Emmet-Kossuth-Palo Alto-Pocahontas-Humboldt-Sac- 258 PM CDT Thu Mar 19 2020 This Hazardous Weather Outlook is for portions of north central Iowa. .DAY ONE...This Afternoon and Tonight A Winter Weather Advisory is in effect for the area tonight. Please refer to the National Weather Service website at weather.gov/desmoines for further details. .DAYS TWO THROUGH SEVEN...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed, but any snowfall reports are appreciated. IAZ006-007-016-017-202000- Winnebago-Worth-Hancock-Cerro Gordo- 258 PM CDT Thu Mar 19 2020 This Hazardous Weather Outlook is for portions of north central Iowa. .DAY ONE...This Afternoon and Tonight Non-severe thunderstorms with moderate to locally heavy rain expected this afternoon. Colder air will turn rain to snow, with less than an inch of accumulation expected. .DAYS TWO THROUGH SEVEN...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed, but any snowfall reports are appreciated. Hagenhoff
The Des Moines radar (KDMX), 118 km away, was scanning. The volume nearest the first event began at 22:12 UTC.
2 hail. Local standard time, as filed.
Trained spotter reported nickel sized hail with 40-50 mph winds resulting in small tree limbs down.
Public report of ping pong ball sized hail.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2020Every state in 2020This day in weather historyWarnings in Iowa, March 2020
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: 881397, 881398.