Multiple rounds of severe storms impacted Iowa on July 30th. This first round occurred through the early morning as a bowing line of storms moved into the area from Nebraska around 1 am CDT.
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.
Multiple rounds of severe storms impacted Iowa on July 30th. This first round occurred through the early morning as a bowing line of storms moved into the area from Nebraska around 1 am CDT. This passed across the area through the early morning hours, exiting into southeastern Iowa by 5 am. Several sites reported wind gusts of 60-65 mph as this line of storms swept across the area. A second bowing segment passed across the are in the mid to late morning, this time bringing hail along with the winds. In its wake, thunderstorms developed on the outflow boundary across central to southeast Iowa. These storms were slow moving and produced heavy rain along with a number of quarter sized and larger hail reports.
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 Jul 29, 11:08 PM CST, 1 hour 6 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Des Moines IA 1208 AM CDT Tue Jul 30 2024 ...Updated for the 06z Aviation Discussion... .KEY MESSAGES... - Heat continues through Wednesday with heat index values over 100F possible, especially in southern and southwest Iowa. - A few strong to severe storms will be possible late tonight into Tuesday morning. Gusty winds and locally heavy rainfall will be the main concerns. - More thunderstorms develop through the day on Tuesday. All severe hazards will be possible, but strong wind gusts will be the primary threat with any organized storms. Additional storm chances then expected again Wednesday into Thursday morning. && .DISCUSSION... Issued at 345 PM CDT Mon Jul 29 2024 A nebulous surface pattern this afternoon shows little in the way of defined features, with generally light and variable flow over the forecast area. However, looking further aloft we can see warmer temperatures beginning to build and upper level ridging fill in behind last nights shortwave. This is translating down to the surface, where temperatures in southwest Iowa are in the upper 80s to near 90. Cloud remnants from the overnight/morning convection then cumulus developing through mid-day has slowed temperatures somewhat, but much of the area is under full sunshine and warming quickly. A few sites have heat index values around 100F with only slow cooling expected into this evening. No changes have been made to the Heat Advisory from the previous shift, with the Advisory remaining in effect for the same areas until 8 pm tonight. Quick on the coat-tails of the trough from early this morning comes a few additional waves with associated shower and thunderstorm chances through mid-week. The first of these chances arrives after midnight tonight, as storms firing in the high plains grow upscale this evening. As is typical for this time of the year, there is a large spread of solutions among guidance on how these MCSs may evolve through the evening. Models depict two areas of convection that could potentially impact the state, one developing in North Dakota and riding along the thermal ridge and another developing along the Nebraska/South Dakota border and propagating east with the mean flow. Uncertainty is pretty high with how these two areas of convection evolve overnight and how they might impact the state early tomorrow morning, if at all. That being said, should an MCS maintain strength as it reaches Iowa overnight into tomorrow, strong to severe wind gusts and locally heavy rainfall would be possible. The lobe of forcing responsible for the convection to our west by this evening will make its way into the state tomorrow, bringing more chances for storms throughout much of the day. Again, there will be a lot of uncertainty on how these play out, as location, timing, and severity will all depend on prior convective trends. Therefore, rather than specifying timing and locations, the main focus should be on the impacts of any storms that do occur. The environment will be favorable for strong to severe storms tomorrow, boasting 40-50+ kts of deep layer shear, 3000+ J/kg of ML CAPE, and plenty of moisture in place. Upscale growth is expected, but there will also be enough low level shear for supercells as well, meaning all severe hazards are possible. That being said, winds look to be the primary concern with DCAPE values of 1000+ J/kg, and would be especially concerning if convection grows into an MCS. Locally heavy rainfall is also expected, with PWATs nearing 2 inches and strong moisture transport into the area. A warm front in place may also promote training storms, which could lead to some ponding water on roads in urban areas. Finally, in addition to the storm chances tomorrow, heat continues to build in with highs in the 90s and heat index values pushing 105 to 110 in southern and southwest Iowa. Another Heat Advisory has been issued to cover this, but the low confidence in convective trends makes the temperature forecast uncertain as well. Therefore, remained a bit conservative with the northern extent of the advisory and held off on any Excessive Heat Warning for the southwest CWA due to the possibility for storms/cloud cover lingering over much of the area through the day. Even so, if the sun makes it out for a few hours tomorrow, it will be quite uncomfortable and potentially dangerous, even if heat index values do not quite reach as high as they could. The heat continues Wednesday as well before another upper trough moves through and slows the heating through the second half of the week. Showers and thunderstorms will likely accompany this trough, with chances for more strong to severe storms again Wednesday into Thursday morning. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1201 AM CDT Tue Jul 30 2024 Thunderstorm complex will sink into the area within the next 6 hours. Highest confidence in impacts at KFOD so have introduced TEMPO group accounting for this. Expect gusts in the 35-40kt range with thunderstorms with some sporadic 50kt gusts possible. Have left VCTS at KDSM and VCSH at other sites due to uncertainty in eastward extent of storms. Additional thunderstorms will become possible near midday and beyond, but remain uncertain until it becomes more clear how overnight and morning thunderstorms progress. More thunderstorms anticipated to arrive in the west at the end of the TAF period. && .DMX WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 1 PM this afternoon to 9 PM CDT this evening for IAZ044-045-057>060-070>075-081>086-092>097. && DISCUSSION...Hagenhoff AVIATION...Jimenez
Hazardous Weather Outlook National Weather Service Des Moines IA Issued by National Weather Service Quad Cities IA IL 321 PM CDT Mon Jul 29 2024 IAZ004>007-015>017-023>028-033>039-046>050-061-062-302030- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun- Webster-Hamilton-Hardin-Grundy-Black Hawk-Greene-Boone-Story- Marshall-Tama-Jasper-Poweshiek- 321 PM CDT Mon Jul 29 2024 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Late this afternoon and tonight Scattered to numerous storms are possible overnight, with any organized storms that may develop being capable of producing strong winds and heavy rain. A few may reach severe limits. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Heat and humidity will build further on Tuesday and Wednesday, leading to peak heat index values in excess of 100 degrees each afternoon. Periodic storms are probable through Thursday with strong to severe storms and heavy rainfall possible on both Tuesday and Wednesday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed Tuesday or Wednesday. IAZ044-045-057>060-070>075-081>086-092>097-302030- Crawford-Carroll-Audubon-Guthrie-Dallas-Polk-Cass-Adair-Madison- Warren-Marion-Mahaska-Adams-Union-Clarke-Lucas-Monroe-Wapello- Taylor-Ringgold-Decatur-Wayne-Appanoose-Davis- 321 PM CDT Mon Jul 29 2024 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Late this afternoon and tonight Heat index values in the upper 90s to 105 will continue across southern Iowa through early evening. Scattered to numerous storms are possible overnight, with any organized storms likely to produce strong winds and heavy rain. A few may reach severe limits. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Heat and humidity will build further on Tuesday and Wednesday, leading to peak heat index values in southern Iowa of 105 to 110 degrees each afternoon. Periodic storms are probable through Thursday with strong to severe storms and heavy rainfall possible on both Tuesday and Wednesday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed Tuesday or Wednesday. MTF
The national radar mosaic for the moment the first event began.
17 thunderstorm wind, 14 hail. Local standard time, as filed.
Multiple branches up to 6 inches down across town with lone larger 12 inch branch down. Flattened corn outside of town. Delayed report, time estimated via radar.
Personal weather station recorded a 60 mph gust.
Emergency manager reported 55-60 mph gusts and heavy rain.
Personal weather station recorded a 66 mph gust.
Report of trees down and a few broken windows at a residence.
Relayed report of extensive tree damage in Harvey. Time estimated from radar.
Personal weather station gusted to 62 mph.
Numerous 4 inch tree branches down in tow. Delayed report, time estimated by radar.
Delayed report, time estimated by radar.
Several reports of tree damage in tow.
Pine tree branch fell and damaged the side of a house roof. Time estimated by radar.
Delayed report. Large tree limb down in image submitted via social media. Time estimated from radar.
Relayed via social media.
Time estimated via radar.
Hail up to golf ball sized.
Large tree snapped near Bos Landen Golf Course. Time estimated via radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2024Every state in 2024This day in weather historyWarnings in Iowa, July 2024
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: 1199907, 1199908, 1199909, 1199910, 1199911, 1199912, 1199913, 1199914, 1199946, 1199947, 1199948, 1199949, 1203703, 1203704, 1203705, 1203706, 1203632, 1203633, 1203635, 1203636, 1203637, 1203638, 1203639, 1203640, 1203641, 1203642, 1203643, 1203644, 1203645, 1203646, 1203647.