Heavy rain fell the morning of August 25th, resulting in some flash flooding in Iowa County. Several inches of rain fell in a few hours.
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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 DVN wrote it up.
Heavy rain fell the morning of August 25th, resulting in some flash flooding in Iowa County. Several inches of rain fell in a few hours.
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 Aug 25, 5:16 AM CST, 1 hour 36 minutes earlier.
Area Forecast Discussion National Weather Service Quad Cities IA IL 616 AM CDT Wed Aug 25 2021 ...AVIATION UPDATE... .SYNOPSIS... Issued at 315 AM CDT Wed Aug 25 2021 Showers and storms have lingered across far northeast Missouri early this morning north of an outflow boundary draped across northern Missouri. Showers and thunderstorms are also blossoming across western and central Iowa ahead of an impulse moving from eastern Nebraska into western Iowa. At 230 AM, temperatures were in the upper 60s to lower 70s. Dewpoints ranged from 64 degrees at Freeport to 66 in the Quad Cities to the lower 70 across far southeast Iowa and northeast Missouri. && .SHORT TERM...(Today and Tonight) ISSUED AT 315 AM CDT Wed Aug 25 2021 A lower confidence forecast again across the area early this morning. A weak disturbance will move across the area early this morning as evident on satellite. The best chances through sunrise will be across far southern Iowa, northern Missouri and adjacent sections of Illinois. Convection is expected to lose intensity as the convergence along the low level jet weakens this morning. Will need to monitor precipitation rates across northern Missouri where rain has lingered overnight for the potential for flashing flooding. Models depict the area on the northern extent of 500 mb ridge with the jet stream just to our north and several weak disturbances moving through the flow today ahead of another shortwave that will move across the area tonight. Thus linger lower pops across the area this afternoon into this evening with the better lift overspreading eastern Iowa after 3 UTC before moving into northwest Illinois prior to 12 UTC, Models depict the better moisture transport vectors well to our west overnight with only weak convergence in our area however abundant moisture is still in place across the region and will continue the threat for heavy rainfall. This were will also be the potential for severe storms with some CAPE building across the region around 1000 to 2000 J/KG with around 20 knots of deep layer shear. For these reasons, SPC has the the area north of Interstate 80 in a marginal risk of severe storms for later today. Given the forecast, high temperatures for today may need to be lowered further if precipitation and clouds linger into the early afternoon. High temperatures were lowered by a couple of degrees from the previous forecast. The current forecast is for high temperatures north of Highway 30 in the upper 80s with lower 90s south. Adjusted dewpoints upward from model blends for today given yesterdays trends and used GFS lamps guidance during the afternoon. This does result in afternoon heat indices around 100 for a couple of hours during the late afternoon. Did not issuance a heat advisory for the area for this reason. .LONG TERM...(Thursday through Tuesday) ISSUED AT 315 AM CDT Wed Aug 25 2021 Thursday-Friday The area looks to reside in the favorable "ring of fire" pattern for convective activity on the northern periphery of the subtropical ridge /heat dome/ and on the southern periphery of the stronger mid/upper level winds attendant to the main belt of westerlies. This will potentially feature gusty, heavy rain storm clusters and corridors of likely to categorical PoPs, though placement is difficult to pin down at this range. Potential for parts of the area, especially south of I-80, to see PM heat indices into heat advisory criteria of 100 to near 105 degrees Thursday and Friday, but limited confidence exists on temperatures given convective debris/outflow boundary potential. Saturday-Saturday night The storm track looks to shift north in strengthening southerly flow ahead of a digging trough in the Intermountain West. This should lead to reduced rain chances during this period, and burgeoning heat/humidity once again with the potential for heat index readings to reach advisory criteria. Sunday-Tuesday A pattern shift still looks on track for late in the weekend, as a shortwave ejects across the Upper Midwest. This will send a cold front through the region bringing relief from the heat with cooler and drier conditions by early in the week. Good forcing for ascent and moisture look to be favorable for widespread thunderstorm chances. Shear also looks pretty decent, and so will have to monitor for strong to severe storms pending the frontal timing and favorable thermodynamics. Some signal exists for a return of unsettled weather toward the middle of next week. && .AVIATION...(For the 12Z TAFS through 12Z Thursday Morning) ISSUED AT 610 AM CDT Wed Aug 25 2021 Thunderstorms are moving into eastern Iowa with storms currently impacting KCID. Ceilings are forecast to remain VFR but period of MVFR visibilities are possible in showers and storms. Showers and storms may impact also KMLI and KBRL through 15 UTC. Storms will slowly dissipate this morning. Scattered showers and storm are possible through the day but timing and placement are difficult to time. Added prob30 for KCID, KDBQ, and KMLI for late in the period as another storm system approaches the area. The better chances late in the period will remain northwest of KBRL. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && SYNOPSIS...Cousins SHORT TERM...Cousins LONG TERM...MM AVIATION...Cousins
Hazardous Weather Outlook National Weather Service Quad Cities IA IL 348 AM CDT Wed Aug 25 2021 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-260900- 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- 348 AM CDT Wed Aug 25 2021 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...TODAY AND TONIGHT Several rounds of thunderstorms are possible through tonight. Periods of heavy rain are possible. There is also a marginal or level one risk of severe thunderstorms. The primary threats are damaging winds and hail. Depending on cloud and storm coverage today, heat indices near 100 are possible this afternoon south of Interstate 80. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY Thunderstorms are forecast at times through weekend. There is a low risk for severe thunderstorms Thursday, with the primary threat being damaging winds. Beyond then, it remains too early to determine the risk for severe weather. Afternoon heat index readings around 100 to 105 are possible for portions of the outlook area Thursday through Saturday, if enough sunshine occurs. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated today or tonight. DC/MM
Special Weather Statement
National Weather Service Quad Cities IA/IL
353 AM CDT Wed Aug 25 2021
IAZ087-250930-
Jefferson IA-
353 AM CDT Wed Aug 25 2021
...Strong thunderstorms will impact portions of northern Jefferson
County through 430 AM CDT...
At 352 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Pleasant Plain to near Libertyville.
Movement was east at 25 mph.
HAZARD...Winds in excess of 30 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Fairfield, Maharishi Vedic City, Pleasant Plain, Brookville,
Fairfield Municipal Airport, Mac Coon Access, Salina, Perlee, East
Pleasant Plain, Germanville, Beckwith and Jefferson County
Fairgrounds.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 4116 9172 4100 9172 4101 9215 4116 9197
TIME...MOT...LOC 0852Z 267DEG 22KT 4115 9191 4100 9205
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH
McClurePRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
602 AM CDT WED AUG 25 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0530 AM HEAVY RAIN 2 SE RIVERSIDE 41.46N 91.55W
08/25/2021 M2.25 INCH WASHINGTON IA PUBLIC
&&
TASPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
742 AM CDT WED AUG 25 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0740 AM HEAVY RAIN PARNELL 41.58N 92.01W
08/25/2021 M3.20 INCH IOWA IA TRAINED SPOTTER
RAINFALL THIS MORNING - STILL RAINING AND
LOTS OF STANDING WATER.
&&
TASThe Quad Cities radar (KDVN), 124 km away, was scanning. The volume nearest the first event began at 12:53 UTC.
1 flash flood. Local standard time, as filed.
Public report of creek flooding, through MPING. Street flooded in town, with lots of standing water. Relayed through broadcast media.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2021Every state in 2021This day in weather historyWarnings in Iowa, August 2021
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: 975963.