Several severe thunderstorms developed across much of eastern Iowa on the evening of May 6, 2023. Storms mainly produced hail up to golf ball size.
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 DVN wrote it up.
Several severe thunderstorms developed across much of eastern Iowa on the evening of May 6, 2023. Storms mainly produced hail up to golf ball size. Through the evening, storms merged and weakened in intensity, but not before producing some wind damage across northern and central Lee County. An isolated tornado also occurred in Muscatine County. Heavy rain also fell from storms as some remained stationary for long periods of time. Most notably, locations north and east of Fairfield, Iowa recorded over two inches of rain.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at May 6, 5:20 PM CST, 1 hour 57 minutes earlier.
Area Forecast Discussion National Weather Service Quad Cities IA IL 620 PM CDT Sat May 6 2023 ...AVIATION UPDATE... .SYNOPSIS... Issued at 250 PM CDT Sat May 6 2023 Warm front was located in northern KS to northern MO into middle TN with temps well into the 80s to lower 90s to the south, while dewpoints were well into the 60s to lower 70s. In the dvn cwa temps were in the mid 60s to mid 70s, with dewpoints in the upper 50s to lower 60s. && .SHORT TERM...(This evening through Sunday) Issued at 250 PM CDT Sat May 6 2023 Key messages: 1) SLGT risk (level 2 of 5) for all of the cwa this evening/tonight. 2) Main threats damaging winds, large hail and possible tornadoes. Details: Late afternoon and tonight: Capping inversion seen on 12z/06 DVN sounding suppressing convection this afternoon. Then CAM's (esp HRRR) consistent in showing a weakening cap and thunderstorms developing later this evening and into tonight as a 40 LLJ kicks in increasing the lift/shear. The main threats will be large hail where elevated storms north of the warm front fire up. If storms can become surface based then tornadoes and damaging winds will also be a threat. A mild night expected with lows well in the mid 50s to mid 60s. Sunday: During the day the capping inversion looks to suppress convection once again. Very warm and humid conditions expected ahead of a digging trough in the Rockies and low pressure in ND. Record or near record highs expected at some locations and as of now Burlington and Moline have the best opportunity (see climate section below). Highs will be in the 80s to near 90. .LONG TERM...(Sunday night through Saturday) Issued at 250 PM CDT Sat May 6 2023 Key messages: 1) Enhanced risk (level 3 of 5) for severe storms Sunday evening and Sunday night. Main risk damaging winds. 2) Marginal risk (level 1 of 5) for Monday in our far south. 3) Warm week ahead with thunderstorm chances returning again late in the week. Sunday evening and Sunday night: Models show a disturbance in the flow arriving with an increase in mid level winds. This will increase the damaging wind risk with the potential for 75+ mph winds, when you add the SBCAPE of 4000-5000 J/kg into the mix. HRRR consistent in showing an intense severe squall line rapidly moving eastward into the dvn cwa late in the evening into the overnight hours. Scattered severe storms are also likely in the evening before the line arrives. Besides the damaging wind threat the risks also include tornadoes and large hail. Monday: A cold front arrives pushing the thunderstorm threat southward and there is still a severe threat (marginal risk) in our far southern counties. It will be cooler with highs in the upper 60s north to upper 70s south. Tuesday through Saturday: Persistent deep trough in the Rockies with a zonal to southwest flow aloft will keep our area in a warm regime with daily highs in the 70s to lower 80s. Thunderstorm chances return late in the week into next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 616 PM CDT Sat May 6 2023 A warm, moist air mass is over the region tonight and Sunday, with thunderstorms possible tonight, and again towards Sunday evening. The exact timing of storms and coverage is very challenging, with tonight's storms uncertain on how widespread they will be on the latest trends. Even if storms are more isolated, the MVFR clouds should once again spread over the area, possibly with some IFR/MVFR visibility as well in the late night and morning hours Sunday. By mid to late morning Sunday, a VFR period may arrive as we heat up and develop a south wind again. A line of severe storms may move into eastern Iowa during the late afternoon and evening Sunday. ERVIN && .CLIMATE... Issued at 250 PM CDT Sat May 6 2023 Record High Temperatures for Sunday May 7, 2023 Burlington 88 1934 Cedar Rapids 98 1896 Dubuque 91 1896+ Moline 88 1965+ && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && SYNOPSIS...Haase SHORT TERM...Haase LONG TERM...Haase AVIATION...Ervin CLIMATE...Haase
Hazardous Weather Outlook National Weather Service Quad Cities IA IL 149 PM CDT Sat May 6 2023 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-071900- Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson- Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson- Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll- Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson- Warren-Hancock-McDonough-Scotland-Clark- 149 PM CDT Sat May 6 2023 This Hazardous Weather Outlook is for portions of north central Illinois...northwest Illinois...west central Illinois...east central Iowa...northeast Iowa...southeast Iowa and northeast Missouri. .DAY ONE...THIS AFTERNOON AND TONIGHT The Storm Prediction Center has a slight or level 2 risk for severe thunderstorms across the entire outlook area this evening into tonight. There is a threat for tornadoes, damaging winds, and large hail. The Mississippi River continues to experience flooding. Please see the latest Flood Statements and Flood Warnings for details. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY There are periodic chances of thunderstorms Sunday through Monday night and again Wednesday night through Friday. There is an enhanced or level 3 risk of severe storms Sunday evening and Sunday night across much of the area with the main threats being tornadoes, large hail, and damaging winds in excess of 75 mph. There is also a Marginal or level 1 risk of severe storms on Monday for Clark and Scotland Counties in Missouri and Hancock and McDonough Counties in Illinois. The main threats are damaging winds and large hail. The Mississippi River will continue to experience flooding through next week. .SPOTTER INFORMATION STATEMENT... Spotter activation will be needed this evening into tonight and again Sunday evening and Sunday night. Haase
Special Weather Statement
National Weather Service Quad Cities IA/IL
814 PM CDT Sat May 6 2023
IAZ087-098-070145-
Van Buren IA-Jefferson IA-
814 PM CDT Sat May 6 2023
...A strong thunderstorm will impact portions of Van Buren and
southern Jefferson Counties through 845 PM CDT...
At 814 PM CDT, Doppler radar was tracking a strong thunderstorm over
Leando, or 11 miles northwest of Keosauqua, moving east at 35 mph.
HAZARD...Winds in excess of 30 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This strong thunderstorm will be near...
Keosauqua and Birmingham around 830 PM CDT.
Other locations in the path of this storm include Stockport and
Bentonsport/Vernon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4092 9218 4097 9173 4070 9173 4072 9218
TIME...MOT...LOC 0114Z 266DEG 32KT 4083 9213
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...30 MPH
ErvinThe Quad Cities radar (KDVN), 155 km away, was scanning. The volume nearest the first event began at 01:16 UTC.
23 thunderstorm wind, 10 hail, 1 tornado, 1 funnel cloud. Local standard time, as filed.
Quarter sized hail, with very strong winds that resulted in some minor damage to the trees.
Eight inch diameter tree limbs downed by strong winds.
Trees blown down and shingles blown off of the roof.
Tree blown down.
There was a 72 mph wind gust reported at the Iowa City Airport ASOS.
This tornado developed just NNW of West Liberty and tracked across the far northeast part of town before eventually crossing over U.S. Highway 6 between West Liberty and Atalissa, and diminishing shortly after. The extent of the damage was mainly to outbuildings, with several walls and roofs collapsed and in some cases blown across a downstream field. A few large trees and two utility poles were also snapped. A large metal batting cage anchored into concrete was twisted and bent sharply at its base.
Semi truck was blown over while driving on Interstate 80. Time was estimated by radar.
Large tree fell on a shed. Time was estimated by radar.
There were 15 to 18 inch diameter branches that were downed by the wind, along with some shingle and siding damage.
Wind gusts estimated between 50 to 60 mph from the thunderstorm.
The AWOS reported a 59 mph wind gust with the thunderstorm.
There was a 12 inch diameter tree that was blown down. Time was estimated by radar.
Estimated winds around 60 mph from the thunderstorm.
The ASOS at Davenport Airport measured a 64 mph wind gust from the thunderstorm.
Tree limbs and power lines down across town.
The AWOS at Clinton Airport measured a 66 mph wind gust.
The ASOS at Davenport Airport measured a 67 mph wind gust.
An off duty NWS employee estimated winds of 70 mph. He also reported nickel sized hail and large tree branches down near 53rd Street and US 61 in Davenport.
There was a 3 inch tree that was snapped by thunderstorm winds. Nearby reports of 60 to 70 mph winds.
Wind from the north estimated to be 80 mph. Strong winds lasted for about 20 minutes. Power went out due to the strong winds. A 6 inch diameter tree limb blown down and smaller branches. Also, some scaffolding was blown down.
Roof torn off of a manufactured home due to the thunderstorm wind gusts.
Large tree branches down by the thunderstorm wind gusts.
There was a 77 mph wind gust reported at the AWOS with the second round of storms.
Funnel clouds going up and down in the clouds occasionally, but never reached the ground.
Parking signs bent over by the thunderstorm winds. Time was estimated by radar.
The ASOS at Burlington Airport measured a 60 mph wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2023Every state in 2023This day in weather historyThe tornado archive for Iowa, 2023Warnings in Iowa, May 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: 1099436, 1099437, 1099440, 1099466, 1099468, 1099443, 1099448, 1099454, 1099459, 1099470, 1099449, 1099463, 1103390, 1103405, 1103392, 1103381, 1103387, 1103370, 1103389, 1103394, 1103372, 1103371, 1103374, 1103391, 1103375, 1103377, 1103383, 1103379, 1103385, 1103384, 1103393, 1103395, 1103396, 1103382, 1103380.