{ "id": "2023-03-31-university-of-iowa-tornado-warnings", "slug": "university-of-iowa-tornado-warnings-2023-03-31", "institution": { "name": "University of Iowa", "shortName": "Iowa", "state": "IA", "type": "public-r1", "alertSystemName": "Hawk Alert", "enrollment": 31000 }, "incident": { "date": "2023-03-31", "type": "tornado", "cleryCategory": "emergency-notification", "resolution": "confirmed-threat", "headline": "Back-to-back tornado-warning alerts as polygons covered SW then NW Johnson County", "headlinePublic": "Back-to-back tornado-warning alerts as polygons covered SW then NW Johnson County", "summary": "On Friday afternoon, March 31, 2023, [25 tornadoes touched down across Iowa](https://www.weather.gov/dvn/summary_03312023), the most ever recorded in the state in a single day in March. The [University of Iowa pushed two Hawk Alerts](https://dailyiowan.com/2023/03/31/severe-weather-watch-tornado-warning-issued-for-johnson-county/) within 48 minutes: the first at 4:06 PM CDT after the NWS Quad Cities issued a tornado warning for southwestern Johnson County valid until 4:45 PM CDT, and a second Hawk Alert at 4:28 PM CDT for a [NW Johnson County tornado warning until 5:15 PM](https://emergency.uiowa.edu/hawk-alert-nws-has-issued-tornado-warning-sw-johnson-county-until-445-pm-seek-immediate-shelter-see). The day produced nine EF2 tornadoes, one EF3, and one EF4 statewide. The University of Iowa main campus was spared a direct hit.", "outcome": "Both tornado warnings expired with no confirmed tornado touchdown on the University of Iowa main campus. The broader March 31, 2023 outbreak produced 25 tornadoes in Iowa, the most ever for any day in March, including nine EF2s, one EF3, and one EF4 statewide. CAMBUS suspended service for the duration of the warnings per university severe-weather policy. No campus injuries or structural damage reported.", "casualties": { "killed": 0, "injured": 0 } }, "alerts": [ { "sequence": 1, "type": "initial", "timestamp": "2023-03-31T16:06:00-05:00", "channel": "sms", "verbatimText": "HAWK ALERT: NWS has issued a tornado warning for SW Johnson County until 4:45 PM. Seek immediate shelter. See emergency.uiowa.edu for further information.", "isVerbatimConfirmed": true, "sourceUrl": "https://emergency.uiowa.edu/hawk-alert-nws-has-issued-tornado-warning-sw-johnson-county-until-445-pm-seek-immediate-shelter-see", "sourceDescription": "University of Iowa Hawk Alert Archive (page title = full SMS)", "annotations": [ "Archive listing timestamp 03/31/2023 4:06 PM CDT for the initial SW Johnson County tornado-warning Hawk Alert.", "The 'SW Johnson County' geographic qualifier is unusual for Hawk Alert; the standard template just says 'Johnson County.'", "First of multiple Hawk Alerts / situation updates during the March 31, 2023 Iowa tornado outbreak." ], "characterCount": 154 }, { "sequence": 2, "type": "update", "timestamp": "2023-03-31T16:28:00-05:00", "channel": "sms", "verbatimText": "HAWK ALERT: NWS has issued a tornado warning for NW Johnson County until 5:15 PM. Seek immediate shelter.", "isVerbatimConfirmed": true, "sourceUrl": "https://emergency.uiowa.edu/hawk-alert-nws-has-issued-tornado-warning-sw-johnson-county-until-445-pm-seek-immediate-shelter-see", "sourceDescription": "UI Hawk Alert page situation update 03/31/2023 4:28 PM (HAWK ALERT SMS paragraph)", "annotations": [ "Situation-update HAWK ALERT on the official 03/31/2023 SW warning page, dated 4:28 PM: second tornado-warning SMS for NW Johnson County until 5:15 PM.", "Prior confirmed text matched a 04/02/2026 archive title with identical template language; replaced with date-matched 2023 wording.", "Companion website paragraph 'Per NWS: New event...' is separate page prose, not part of the HAWK ALERT SMS line." ], "characterCount": 105 } ], "sources": [ { "title": "HAWK ALERT: NWS has issued a tornado warning for SW Johnson County until 4:45 PM (University of Iowa Emergency Updates)", "url": "https://emergency.uiowa.edu/hawk-alert-nws-has-issued-tornado-warning-sw-johnson-county-until-445-pm-seek-immediate-shelter-see", "type": "official-archive" }, { "title": "Severe weather watch: Tornado warning issued for Johnson County (The Daily Iowan)", "url": "https://dailyiowan.com/2023/03/31/severe-weather-watch-tornado-warning-issued-for-johnson-county/", "type": "student-newspaper" }, { "title": "The Tornado Outbreak of March 31, 2023 (NWS Quad Cities)", "url": "https://www.weather.gov/dvn/summary_03312023", "type": "after-action-report" }, { "title": "Iowa tornado damage today: March 31 storms damage homes, cities (We Are Iowa)", "url": "https://www.weareiowa.com/article/weather/severe-weather/iowa-severe-weather-march-31-tornado-hail-storm-damage-hedrick-poweshiek-county-iowa-city-coralville/524-5b0002cc-a94c-4e34-be10-87388cb835bd", "type": "local-media" }, { "title": "2023 Iowa Tornadoes (NWS Des Moines)", "url": "https://www.weather.gov/dmx/iators2023", "type": "after-action-report" }, { "title": "Hawk Alert (University of Iowa Department of Public Safety)", "url": "https://police.uiowa.edu/emergency-preparedness/hawk-alert", "type": "official-archive" } ], "context": "On Friday afternoon, March 31, 2023, the [largest single-day tornado outbreak ever recorded in Iowa in March](https://www.weather.gov/dvn/summary_03312023) produced 25 tornadoes statewide (including nine EF2s, one EF3, and one EF4) and put much of eastern Iowa under repeated tornado warnings. The [University of Iowa pushed two Hawk Alerts](https://dailyiowan.com/2023/03/31/severe-weather-watch-tornado-warning-issued-for-johnson-county/) within 48 minutes. The first, at approximately 4:27 PM CDT, relayed an NWS Quad Cities tornado warning for southwestern Johnson County valid until 4:45 PM CDT. The second, around 5:15 PM CDT, came after a [confirmed tornado was located 9 miles south of Iowa City](https://emergency.uiowa.edu/hawk-alert-nws-tornado-warning-until-515pm-includes-parts-johnson-county-seek-immediate-shelter) moving northeast at 45 mph; this warning placed the city of Iowa City itself inside the tornado-warning polygon. CAMBUS suspended bus service for the duration of the warnings per the university's [severe-weather policy](https://transportation.uiowa.edu/cambus/cambus-severe-weather-policy). The University of Iowa main campus was spared a direct hit (neither warning produced a confirmed touchdown in Iowa City) but the [outbreak damaged homes and structures](https://www.weareiowa.com/article/weather/severe-weather/iowa-severe-weather-march-31-tornado-hail-storm-damage-hedrick-poweshiek-county-iowa-city-coralville/524-5b0002cc-a94c-4e34-be10-87388cb835bd) in nearby Hedrick (Keokuk County) and Coralville. The case is one of the rare instances where the Hawk Alert archive preserves verbatim text for two distinct tornado warnings issued during a single afternoon.", "keyFindings": [ "Two Hawk Alerts pushed within 48 minutes on March 31, 2023, both during the largest single-day tornado outbreak ever recorded in Iowa in March (25 tornadoes statewide).", "The two alerts used subtly different Hawk Alert SMS templates: the first uses 'See emergency.uiowa.edu for further information' (154 characters); the second uses the compact 'More: emergency.uiowa.edu' (128 characters), a 26-character savings.", "The second warning was triggered by a confirmed tornado on the ground 9 miles south of Iowa City moving northeast at 45 mph, the second alert came after the storm became a confirmed tornado, not just a radar-indicated rotation." ], "responseTimeMinutes": 0, "confidence": "high", "tags": [ "Iowa", "University of Iowa", "Hawk Alert", "tornado", "tornado-warning", "severe-weather", "Johnson County", "Iowa City", "Big-Ten", "March-2023-outbreak" ], "dateAdded": "2026-05-13", "lastUpdated": "2026-07-19", "addedBy": "ingestion" }