Severe drought conditions persisted for the month of August with widespread heat and below normal rainfall for much of August. A generous widespread rainfall late in the month helped to improve conditions on August 31st.
Every event with a place to put it; 9 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Severe drought conditions persisted for the month of August with widespread heat and below normal rainfall for much of August. A generous widespread rainfall late in the month helped to improve conditions on August 31st.
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 31, 11:02 PM CST, 58 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1202 AM CDT Sun Aug 1 2021 .SHORT TERM.../Tonight through Sunday Night/ Issued at 234 PM CDT Sat Jul 31 2021 Confidence: High Clouds linger late this afternoon over the south with the departing cool front and associated area of overnight convection. Subjective surface analysis at 12z shows one front south of Iowa with another weak boundary over central MN moving southeast, along with a third cool front over northeast MN. Low pressure is stacked up over the northern Great Lakes near Lake Superior while high pressure is now beginning to enter the Northern Plains. Aloft, a large gyre at H850 over New England will be merging with a low currently over Hudson Bay. High pressure continues across the west with ridging far north into the Canadian provinces. Cooler temperatures will continue to be slated for the eastern/northeast states while rather hot conditions will rebuild over the west. As the weak boundary over central MN heads south this evening, a few showers and isolated thunderstorms are expected to develop with an area of instability along the boundary. The activity will be mainly diurnal and if it holds together this evening, likley not making it any farther south than the US30 corridor in the northeast. As well as a chance of showers and isolated thunderstorms north, smoke is again showing up in the visible imagery over northwest and north central Iowa. Hazy to smoky skies are reported from Ft. Dodge north to Algona and Estherville and across southern MN as well. Have already added smoke to grids over the north this afternoon. Current HRRR modeling of the smoke has it tracking south with the boundary overnight into southern Iowa by daybreak. Lows tonight will cool most areas and drop into the mid 50s northwest to the lower to mid 60s southeast. There may be only a little break early Sunday, but another large plume of smoke in northern MN now, tied to the third cold front identified this morning, will likely also track south southeast which brings it close to southeast MN by 12-15z tomorrow and should again clip our northeast and eastern counties through at least the morning tomorrow. With the broad area of high pressure and reinforcing cooler H850 temperatures anticipated to arrive and continue for several days, afternoon highs Sunday will cool a bit to the mid to upper 70s with a few lower 80s over the region. Sunday night will also be refreshingly cool with overnight lows in the lower to mid 50s north to the upper 50s southeast. .LONG TERM.../Monday night through Saturday/ Issued at 234 PM CDT Sat Jul 31 2021 Confidence: Medium to High A combination of several waves dropping nearly due south into the large eastern North American trough at H500 and a cyclone in the Gulf of Alaska/North Pacific off the BC Coast through Thursday will result in a more amplified regime with much of the Great Lakes and eastern plains seeing northwest flow aloft through Tuesday. With H850 temperatures struggling to move much higher than the lower to mid teens through Wednesday afternoon, afternoon highs over the region will be rather pleasant in the upper 70s to lower 80s for the first half of the week. Through Wednesday, generally dry conditions can be expected with occasional clouds due to weak system passage and diurnal heating considerations. By mid to late week and into the weekend, the H500 pattern will begin to flatten with a wave approaching the area from the west Thursday into Friday. With increasing warm air advection and moisture, showers and thunderstorms will be on the increase over the area. The precipitation will signal the beginnings of another round of hotter conditions across our area. Despite some significant differences between mid-range model guidance, a conservative increase in H850 temperatures back to a 20 to 23C range by Friday into Saturday will have our area highs pushing back into the upper 80s to lower 90s again. There are hints in both the Euro and GFS solutions that another wave will track through the region about this time, bringing some additional chance for showers and storms. Though there is no real way to predict levels of smoke across the region into late week, the general pattern would suggest that some will still be lingering due to the overall persistent northwest flow through Tuesday and more westerly flow aloft Wed through Saturday. This may have some impact on highs and visibility/haze from time to time. && .AVIATION.../For the 06Z TAFS through 06Z Sunday night/ Issued at 1202 AM CDT Sun Aug 1 2021 Little change in thinking since 00z. The only non-VFR impact of concern will be smoke with periods of MVFR conditions anticipated at all TAF sites, the most lengthy of which will occur south and east. Otherwise expect VFR conditions with intermittent smoke aloft through the period, along with little beyond patchy higher based cumulus and generally lighter NW winds. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && SHORT TERM...REV LONG TERM...REV AVIATION...Small
Hazardous Weather Outlook National Weather Service Des Moines IA 1228 AM CDT Sun Aug 1 2021 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-020530- 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- 1228 AM CDT Sun Aug 1 2021 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Sunday through Friday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
9 drought. Local standard time, as filed.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Winnebago County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Worth County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Hancock County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Pocahontas County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Sac County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Calhoun County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Greene County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Boone County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
Persistent heat and lack of rainfall during much of August allowed severe drought to continue for much of the month in Poweshiek County. Generous widespread rainfall late in the month helped conditions improve on August 31st.
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: 981557, 981558, 981559, 981560, 981561, 981562, 981563, 981564, 981565.