Large upper level ridging was in place for several days in late May to early June. With little movement in the Great Lakes area surface high, Iowa experiences afternoon thunderstorms largely driven by good moisture transport and diurnal heating each day.
Every event with a place to put it. 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.
Large upper level ridging was in place for several days in late May to early June. With little movement in the Great Lakes area surface high, Iowa experiences afternoon thunderstorms largely driven by good moisture transport and diurnal heating each day. On the afternoon of June 2nd, a couple storms manages to strengthen more than the others scattered across the area, producing damaging wind gusts in Des Moines and Marshalltown, IA.
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 2, 11:22 AM CST, 1 hour 36 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1222 PM CDT Fri Jun 2 2023 ...Updated for the 18z Aviation Discussion... .DISCUSSION.../Today through Thursday/ Issued at 354 AM CDT Fri Jun 2 2023 Key messaging highlights: * Little change into the weekend, with mainly afternoon chances for showers and isolated storms * Additional chances for showers around Mon/Tue, then drier later next week * Seasonal humidities giving way to unusually low dewpoints into the middle of next week Expectations haven't changed a whole lot from this time yesterday with our weather mainly influenced by two large scale patterns. The first will be our gradual transition from the current Great Lakes upper ridge to more anomalous upper level ridging from the northern Plains into Canada through early next week. This has shifted a tad west over recent runs, but won't have a big impact on our sensible weather. Our mainly diurnal, unorganized precip cycle will persist but with gradually decreasing coverage and strength as easterly low level flow becomes more prevalent pushing our better low level theta-e axis and instability farther west. At onset this morning, isolated showers and storms and plenty of mid cloudiness continue to drift slowly north through the forecast area. The airmass remains quite homogeneous with little baroclinicity, but just enough 1-3km moisture transport remains in place for just a bit of a nocturnal forcing in the weak low level jet response. Later this afternoon, additional surface based convection is anticipated into peak heating, better chances west, and most storms would be sub-severe as effective shear remains quite low. Locally heavy rains remain a concern however with moist soundings and mean winds only 5-10kts. Similar cycles are anticipated into the weekend, but with weaker and more isolated precip moving east to west around the base of the northern ridge. By Tuesday our second pattern regime will begin with weak, but larger scale forcing advancing with the noted and deep back door cool front. This will bring chances for mainly showers before the precipitation essentially goes to nothing by the middle of next week. Guidance is in better agreement with the progression of a large eastern CONUS closed low, whose influences have nudged farther west with time as well. This will bring us weak north flow aloft, and MS Valley surface ridging. Temps will remain mild, but closer to seasonal normals. However the most noted change will be anomalous drying through the column, including surface dewpoints. Dewpoints are expected to dip into the refreshing 40s, and potentially 30s east, by Wednesday and Thursday. && .AVIATION.../For the 18Z TAFS through 18Z Saturday afternoon/ Issued at 1222 PM CDT Fri Jun 2 2023 VFR conditions will prevail through the TAF period. Isolated to scattered thunderstorms are forecast at times, especially between about 20Z and 03Z this afternoon/evening, however probability and expected duration of any impacts at a given terminal are too low/uncertain to advertise. Did put in a targeted VCTS group at FOD where odds of impact are slightly however, however, at all terminals amendments are a possibility later today as radar and short-term observational trends dictate. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && DISCUSSION...Small AVIATION...Lee
Hazardous Weather Outlook National Weather Service Des Moines IA 400 AM CDT Fri Jun 2 2023 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-030900- 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- 400 AM CDT Fri Jun 2 2023 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight A few isolated showers and thunderstorms are expected to continue this morning, with additional scattered thunderstorms expected this afternoon into the evening. Locally heavy rain will be possible, which may lead to ponding of water in low lying and poor drainage or urban areas. Otherwise, the threat of severe weather is low. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Thunderstorm chances will continue largely through the weekend and into early next week. Saturday may see storms more isolated to portions of western and central Iowa, before returning more widespread across the state Sunday through Tuesday. Again the severe weather risk will be low, but slow moving storms may produce locally heavy rain and result in localized ponding, especially in urban areas. Otherwise expect lightning and gusty winds at times with any storms. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated, but rainfall reports are always appreciated.
The Des Moines radar (KDMX), 72 km away, was scanning. The volume nearest the first event began at 18:57 UTC.
3 thunderstorm wind. Local standard time, as filed.
Delayed report of a large, healthy tree snapped at the trunk near Ferguson. Estimated sized was 2.5 feet in diameter. Report via social media.
Six inch diameter tree limb down. Image submitted via social media.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2023Every state in 2023This day in weather historyWarnings in Iowa, June 2023
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: 1105614, 1105615, 1105616.