Very warm temperatures and much below normal rainfall led to the expansion of drought conditions in portions of west central Iowa in July.
Every event with a place to put it; 2 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.
Very warm temperatures and much below normal rainfall led to the expansion of drought conditions in portions of west central Iowa in July.
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 27, 10:47 PM CST, 1 hour 13 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1147 PM CDT Mon Jul 27 2020 ...Updated Aviation Discussion... .DISCUSSION.../Tonight through Monday/ Issued at 235 PM CDT Mon Jul 27 2020 This week will be fairly benign with seasonal temperatures and relatively comfortable humidity levels. There will be a few chances for showers and storms but the severe threat at this point looks minimal and heavy rainfall does not look to be in the cards. For tonight into Tuesday, a large Canadian low with an associated trough over the Great Lakes will move very little while an upper level ridge builds over the Rockies. This will put much of the Upper Midwest in a northwest flow which will bring in seasonal highs and less humid air. Tuesday afternoon a very weak shortwave continues to be depicted by the models along with a weak surface boundary dropping into northern Iowa. There is very little instability and no shear but there is some weak convergence along the front...mainly east of our forecast area. This may be enough to kick off some isolated showers/storms over far northern Iowa in the afternoon but confidence is low in anything developing and even less that it would be more than an isolated storm. There is little to no risk of severe or heavy rainfall. Late Tuesday afternoon or early evening, the shortwave exits east and the rain threat ends. On Wednesday that weak frontal boundary that was sagging into northern Iowa Tuesday, will have made it's way into northern Missouri or there about and begin to move northward back into southern Iowa or near to our border. Moisture return will be associated with the boundary bringing the possibility of isolated showers/storms back to southern Iowa. At this point it is unclear how far north that boundary will travel. The GFS has been consistent in pushing in into central Iowa while the Euro keeps it mostly in Missouri. I kept the chance PoPs we had going south and west through Thursday but again with low confidence and even if we do see something, isolated to maybe scattered storms is what we will get. Later Thursday, high pressure will begin to nose in from the north, further complicating just how far that front will move into Iowa. From Friday into the weekend, the high takes over and we will be cool for late July/early August and dry. A decent shortwave that develops Thursday over the Rockies and Plains slides southeast and tries to develop a closed low. Where and if that happens may increase chances for rain across the south but confidence is low at this point and precip chances were left out of the forecast beyond Thursday. && .AVIATION.../For the 06Z TAFS through 06Z Tuesday night/ Issued at 1147 PM CDT Mon Jul 27 2020 VFR conditions to persist through the entire TAF period. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && DISCUSSION...FAB AVIATION...Podrazik
Hazardous Weather Outlook National Weather Service Des Moines IA 322 PM CDT Mon Jul 27 2020 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-282030- 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- 322 PM CDT Mon Jul 27 2020 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Isolated thunderstorms are possible Tuesday afternoon over northern Iowa and then Wednesday into Friday with the highest chances over southwest Iowa. The severe threat appears low at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated. Ansorge
The national radar mosaic for the moment the first event began.
2 drought. Local standard time, as filed.
Acute short term dryness led to the development of severe drought conditions in portions of Crawford county during the last days of July.
Acute short term dryness led to the development of severe drought conditions in portions of Pocahontas county during the last days of July.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2020Every state in 2020This day in weather historyWarnings in Iowa, July 2020
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: 915457, 915458.