Very warm temperatures and well below normal rainfall led to the development of drought conditions in portions of west central and central Iowa in July. These conditions slowly expanded in area through the month.
Every event with a place to put it; 11 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 well below normal rainfall led to the development of drought conditions in portions of west central and central Iowa in July. These conditions slowly expanded in area through the month.
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 13, 10:57 PM CST, 1 hour 3 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1157 PM CDT Mon Jul 13 2020 ...Aviation Update... .DISCUSSION.../Tonight through Monday/ Issued at 224 PM CDT Mon Jul 13 2020 Main concern is tonight into Tuesday in the short term. The ridge that has been in place over us gets pushed eastward and a cold front begins dropping southward into our area. Showers and thunderstorms begin entering our area late tonight...before 12Z...and continue southeastward across the entire CWA during the day. Instability is enough for some stronger storms late tonight. Best shear lags the front however. Expect some refiring/reinentisifcation later in the day on Tuesday as the front continues sagging southeastward. Strong/severe storms are possible again Tuesday afternoon...with relatively high CAPEs and shear. In addition to strong/severe storms...attention then turns to heavy rainfall potential Tuesday afternoon and Tuesday night. Some models have PWATs as high as 1.75 to 2 inches. Some models also have some training along the front. Although flash flood guidance values are relatively high...higher rainfall amounts from some of the stronger storms may lead to at least ponding and maybe some localized flash flooding. Precip moves out on Wednesday but then chances return late Thursday into Friday, due to warm air advection behind the departing high. Precip chances then return over the weekend. Heat returns too, with highs in the 90s possible on Saturday. && .AVIATION.../For the 06Z TAFS through 06Z Tuesday night/ Issued at 1152 PM CDT Mon Jul 13 2020 General trend for a slower progression of showers/storms continues, yielding mentions of VCTS and/or prevailing TSRA ramping up around/after 21z at KFOD/KMCW/KALO, 00z at KDSM, and 03z at KOTM. Leading into storms, VFR will prevail with southerly winds gusting to around 20kts as mixing increases. Generally kept MVFR (vis) mentions with TSRA, but can expect IFR/LIFR conditions during worst conditions. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && DISCUSSION...Zogg AVIATION...Curtis
Hazardous Weather Outlook National Weather Service Des Moines IA 356 PM CDT Mon Jul 13 2020 IAZ004>007-015>017-023>026-033>036-044>047-057-058-070-142100- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Sac-Calhoun-Webster-Hamilton- Crawford-Carroll-Greene-Boone-Audubon-Guthrie-Cass- 356 PM CDT Mon Jul 13 2020 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight Thunderstorms are possible tonight. At this time there is a marginal risk of severe weather. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Strong to severe thunderstorms are possible Tuesday afternoon into Tuesday evening. Large hail and damaging winds are the main threats with tornadoes also possible in the afternoon. Some of the thunderstorms Tuesday may also produce locally heavy rainfall that results in ponding of water on roads, highways and interstates as well as possible urban flooding. Hot weather conditions are possible this weekend. Heat index values may be in the 100 to 105 degree range. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed Tuesday afternoon and evening. IAZ027-028-037>039-048>050-059>062-071>075-081>086-092>097-142100- Butler-Bremer-Hardin-Grundy-Black Hawk-Story-Marshall-Tama-Dallas- Polk-Jasper-Poweshiek-Adair-Madison-Warren-Marion-Mahaska-Adams- Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne- Appanoose-Davis- 356 PM CDT Mon Jul 13 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 Strong to severe thunderstorms are possible Tuesday afternoon into Tuesday evening. Large hail and damaging winds are the main threats with tornadoes also possible in the afternoon. Some of the thunderstorms Tuesday may also produce locally heavy rainfall that results in ponding of water on roads, highways and interstates as well as possible urban flooding. Hot weather conditions are possible this weekend. Heat index values may be in the 100 to 105 degree range. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed Tuesday afternoon and evening. Kotenberg
The national radar mosaic for the moment the first event began.
11 drought. Local standard time, as filed.
Acute short term dryness led to the development of severe drought conditions in much of Adair county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions over much of Cass county in the latter half of July.
Acute short term dryness led to the development of severe drought conditions in far northwest Madison county in the latter half of July.
Acute short term dryness led to the development of severe drought conditions in much of Audubon county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in all of Guthrie county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in much of Dallas county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in far northwest Polk county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in much of Carroll county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in much of Greene county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in central and southern Boone county during the later half of the month of July.
Acute short term dryness led to the development of severe drought conditions in far southwest Story county during the later half of the month 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: 915430, 915433, 915435, 915437, 915439, 915441, 915442, 915445, 915447, 915448, 915450.