Storms initiated west of the area over portions of Nebraska and Kansas in the overnight hours of the 28th into the 29th, eventually leading into and across southern Iowa during the morning hours of the 29th. These storms were situated within a fairly supportive environment, including a north south gradient of MUCAPE values in the 2000 to 4000+ J/kg range, 30 to 40+ kts of effective shear, and…
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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.
Storms initiated west of the area over portions of Nebraska and Kansas in the overnight hours of the 28th into the 29th, eventually leading into and across southern Iowa during the morning hours of the 29th. These storms were situated within a fairly supportive environment, including a north south gradient of MUCAPE values in the 2000 to 4000+ J/kg range, 30 to 40+ kts of effective shear, and steering flow supportive of MCS maintenance. Eventually, linear storm mode evolved into an MCV. Resulting storms produced a number of strong wind and wind damage reports, including trees downed and measured winds to 67 mph.
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 29, 5:41 AM CST, 2 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 641 AM CDT Thu Jun 29 2023 ...Updated for the 12z Aviation Discussion... .DISCUSSION.../Today through Wednesday/ Issued at 300 AM CDT Thu Jun 29 2023 Key Messages: - Storms moving across southern Iowa this morning. An increasing threat for damaging winds over far southern Iowa. - A few more rounds of storms late tonight through Saturday. Low pressure is situated over southeast Colorado this morning with a warm front extending east through central Kansas and into northern Missouri. A expansive plume of 70+ dew points extends from the Gulf Coast and into southeast Nebraska/southwest Iowa. Most model solutions are under done on the dew points on this northern end which is a bit concerning, more on that later. At 06z, the low level jet was focused into central Kansas and it will lift northeast and be focused towards far southwest Iowa by 12z and in the meantime, a 500 mb jet max is moving over Nebraska. Supercells are currently ongoing over south central and southwest Nebraska with some weaker warm advection convection extending east/southeast from the stronger storms. This current setup has the look of a developing derecho that will move somewhere from far southern Iowa and/or northern Missouri and into Illinois today as these storms move along a strong instability axis that extends from west to east. This instability axis will be even stronger than model projections with the higher dew points in place. The exact movement is still yet to be determined as the right mover Bunkers motions are slightly south of east currently then turn more easterly in the next few hours. These storms may maintain HP supercell characteristics for a while but may eventually evolve into a linear system and maintain an easterly direction. It is also possible the storms weaken a bit before strengthening again by mid morning as surface based instability increases. SPC has placed an Enhanced Risk for severe weather over far southern Iowa for today. This is conditional on the track of these storms. The remainder of the day and likely evening should be mostly quiet outside of a few storms that may develop over north central Iowa late this afternoon. A few more rounds of storms are expected yet through Saturday. As has been discussed that past several days, the main upper level system will move out of the western CONUS Friday and will reach the state by late Saturday. Another complex of storms is expected to develop tonight and move across the southern half of Iowa followed by renewed scattered storm development in the afternoon area wide. Then storm chances persist Friday night into Saturday. A few severe storms are possible through the period. Saturday is interesting with the upper low arriving during the day along with light winds and good stretching potential, could lead to favorable conditions for a few landspouts. A few showers and storms may linger into Sunday with the state still in the cyclonic curvature of the departing upper level low and Monday will remain the the northwest upper flow. That upper flow will transition to westerlies by mid next week and the pattern will likely remain active. Have precipitation chance in the forecast for July 4th but it should remain mostly dry across much of the area followed by greater precipitation chances on the 5th. Temperature wise, Saturday is looking to be the cool day with highs in the 70s and 80s with mostly cloudy skies and showers and storms around. Otherwise highs will generally be in the 80s while touching low 90s over southern Iowa at times. Smoke today should improve with lowering concentrations today as it gradually shifts back to the east. && .AVIATION.../For the 12Z TAFS through 12Z Friday morning/ Issued at 635 AM CDT Thu Jun 29 2023 Thunderstorms will impact southern Iowa this morning with KOTM having the greatest chance. A few isolated storms are possible vicinity KMCW late this afternoon with additional storms possible later tonight over western Iowa. Areas of fog and smoke are ongoing over eastern Iowa. The vsbys will gradually improve this morning. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && DISCUSSION...Donavon AVIATION...Donavon
Hazardous Weather Outlook National Weather Service Des Moines IA 344 AM CDT Thu Jun 29 2023 IAZ004>007-015>017-023>028-033>039-300845- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun- Webster-Hamilton-Hardin-Grundy-Black Hawk- 344 AM CDT Thu Jun 29 2023 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight Isolated thunderstorms are possible this evening across northern Iowa. At this time, severe risk appears low. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Additional storms are expected Friday into Saturday and Sunday, which could become strong, though the severe hazards will be better evaluated in the coming forecast periods. .SPOTTER INFORMATION STATEMENT... Spotters may be needed at times through Saturday. IAZ044>050-057>062-070>075-081>086-092>097-300845- 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 AM CDT Thu Jun 29 2023 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight Severe storms are anticipated across southern Iowa through the morning and into midday. Damaging winds will be the primary hazard, though large hail and even a tornado are possible, especially towards southeast Iowa. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Additional storms are expected Friday into Saturday and Sunday, which could become strong, though the severe hazards will be better evaluated in the coming forecast periods. .SPOTTER INFORMATION STATEMENT... Spotters may be needed at times this morning through Saturday. Hagenhoff
The Des Moines radar (KDMX), 123 km away, was scanning. The volume nearest the first event began at 13:53 UTC.
14 thunderstorm wind. Local standard time, as filed.
Lamoni Municipal Airport ASOS recorded a thunderstorm wind gust of 67 mph.
Public reported measured wind gusts to 63 mph, including damaged and downed tree branches.
Law enforcement relayed public report of a tree down in Orient. This is ad elayed report and time estimated from radar.
Emergency manager reported power lines and trees down. Time estimated from radar.
Trained spotter reported tree limbs down.
WHO relayed reports of trees and limbs down. Straight line winds lasted for 10 to 15 minutes.
Emergency manager reported tree down on West North Street.
NWS Employee related that half of a large tree was snapped. This is a delayed report and time estimated from radar.
NWS employee relayed couple of medium sized trees snapped halfway down. This is a delayed report and time estimated from radar.
Trained spotter reported multiple healthy, live trees blown over or snapped off. This is a delayed report and time estimated from radar.
NWS employee reported trees down. This is a delayed report and time estimated from radar.
Public reported large branches and limbs down and power out for a bit. Time estimated from radar.
Trained spotter reported estimated 50 to 60 mph wind gusts, and part of a tree down on a power line on the south side of Ottumwa.
Public relayed pictures of a tree that fell on and damaged part of a home. Time estimated from radar.
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: 1106502, 1106503, 1106504, 1106520, 1106523, 1106526, 1106529, 1106532, 1106536, 1106539, 1106542, 1106544, 1106545, 1106547.