Minimal rainfall during the summer led to the continued deterioration of conditions across portions of west central into central Iowa. Extreme drought conditions developed in early August and remained for the rest of the month as little rainfall occurred.
Every event with a place to put it; 17 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.
Minimal rainfall during the summer led to the continued deterioration of conditions across portions of west central into central Iowa. Extreme drought conditions developed in early August and remained for the rest of the month as little rainfall occurred. August ended up being the 3rd driest on record across Iowa with slightly above normal temperatures. Along with maturation of field crops, soil moisture became very low with small streams drying up by the end of the month in many locations in the extreme area.
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, 10:39 PM CST, 1 hour 21 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1139 PM CDT Fri Jul 31 2020 ...Updated Aviation Discussion... .SHORT TERM.../Tonight through Saturday/ Issued at 331 PM CDT Fri Jul 31 2020 High pressure, scattered cloud cover and the advection of cooler temperatures from the north remain the main story for today. There is an increasing signal for fog development over the northeast and a small area of the southwest CWA tomorrow morning. The duration of any fog impacts should be short-lived. Precipitation returns to the forecast on Saturday afternoon with an incoming cold front from the northwest. This weak mid-level shortwave will bring some rain and scattered storm chances Saturday afternoon/evening into Sunday but severe weather potential remains low due to the lack of any significant instability and with little available shear. Although this appears to be a slow-moving system, the ongoing dry conditions combined with the expected low intensity storms should not cause any significant hydro issues. .LONG TERM.../Saturday night through Friday/ Issued at 331 PM CDT Fri Jul 31 2020 Upper level trough aloft will be slowly progressing eastward on Sunday as the upper level ridge remains parked over the western CONUS. As the upper level trough departs the area, lingering QG convergence will promote clouds and even showers and storms. The highest concentration of clouds and showers and storms will be over eastern into parts of central Iowa. Behind this front, cooler air will move into Iowa early next week as 850mb temperatures drop below 10C. This will result in very pleasant conditions for early August with highs in the 70s, which will be about 5 to 10 degrees below normal. The upper level ridge over the western US will be flattened next week as a shortwave trough moves over the southern Canadian provinces. The GFS progression and flattening is faster than the ECMWF and how quickly the thermal ridge moves back into the area. If the GFS pans out correctly, there may be more chances of storms into the region mid to late next week whereas the ECMWF is drier through the end of the week. && .AVIATION.../For the 06Z TAFS through 06Z Saturday night/ Issued at 1137 PM CDT Fri Jul 31 2020 Fog possible at MCW and possibly ALO and left mention of MVFR visibility at those two locations. Otherwise, VFR conditions are likely to prevail throughout the TAF period with a weak cold front to push through the state late Saturday afternoon and will bring a wind shift to the northwest and scattered showers. No mention of showers/storms attm due to the low confidence in timing and location of occurrence. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && SHORT TERM...KCM LONG TERM...Ansorge AVIATION...Podrazik
Hazardous Weather Outlook National Weather Service Des Moines IA 318 PM CDT Fri Jul 31 2020 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-012030- 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- 318 PM CDT Fri Jul 31 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...Saturday through Thursday Scattered thunderstorms are possible Saturday afternoon through Sunday and again by the middle of next week. Severe weather is not anticipated at this time. .SPOTTER INFORMATION STATEMENT... Spotters will not be needed.
The national radar mosaic for the moment the first event began.
17 drought. Local standard time, as filed.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Sac county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Calhoun county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Webster county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Crawford county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of extreme drought conditions in Carroll county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Greene county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Boone county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Audubon county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Guthrie county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Dallas county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Cass county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe to extreme drought conditions in Adair county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe drought conditions in Pocahontas county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe drought conditions in Hamilton county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe drought conditions in Story county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe drought conditions in Madison county during the month.
Very dry conditions since late spring and the continuation of these conditions in August led to the expansion of severe drought conditions in Polk county during the month.
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, August 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: 915593, 915596, 915597, 915600, 915602, 915630, 915631, 915632, 915634, 915635, 915636, 915637, 915639, 915642, 915645, 915646, 915648.