Key Points
- Precipitation has been greater than normal for much of the state in the past 30 days, and we hope to see continued improvements in surface and subsoil moisture.
- Transitioning to La Niña this summer.
- Heavy recent rainfall likely delayed planting progress and caused some concerns for flooding, particularly in southern Iowa.
Past Weather
An active weather pattern brought some severe weather and heavy rain to the state during the past week. As of today, 55 tornadoes have been reported for 2024 in the preliminary tornado summary for Iowa. Between 2003-2022, Iowa averaged 53 tornadoes per year. Between 1980-2019, only 3.2% of Iowa tornadoes were rated EF3 or higher. Hail was also a concern. The preliminary hail summary shows there were 55 reports of severe hail, 1 inch or larger, in April. Damage could have occurred on vulnerable vegetation.
Temperatures were slightly above average during the past week. Southern Iowa was warmest with temperatures around 60°F and northern Iowa stayed coolest with temperatures around 50°F. The climatological averages for daily high and low temperatures in early May are 68°F and 48°F, respectively. The last week has brought 1-4 inches of rain across the state, with southeast Iowa seeing the greatest amounts. Much of Iowa received around 4 inches of rain in the last 30 days, with southeast Iowa, again, receiving the majority, with more than 6 inches of rain. Surface runoff has improved, back into “normal” levels of surface runoff for spring.
Soil Conditions
Soil temperatures continue to hover right around 55°F across the state and are forecasted to stay near 60°F for the next 7 days. Surface moisture helps conserve soil temperatures and reduces the ability for soil to warm up or cool down quickly.
Drought improvements continue. Several areas across Iowa saw a 1-class improvement from last week. NASS crop progress reports also show improvements in topsoil and subsoil moisture. Topsoil moisture is considered 68% adequate and improved by 8%. Subsoil moisture is considered 53% adequate and improved by 10%.
Planting Conditions
Wet soils and an active weather pattern slowed progress on planting and other field operations. However, many acres were planted when possible. Corn progress is at 39% planted and soybeans are 25%, as of April 28th. This is up from last week but will likely see a slow-down when reports for this week come out next week, due to all of the rainfall.
Weather and Climate Outlook
More precipitation is expected across Iowa in the next 7 days, with around 1-2 inches expected. This will come as two separate low-pressure systems move to the plains off the Rockies, the first moving in on Saturday and the second sometime on Monday.
The 8-14 day outlook from the Climate Prediction Center shows a slight chance of temperatures leaning
below normal and near normal chances for precipitation. The May outlook shows equal chances for above or below normal temperatures and precipitation. The three-month outlook shows equal chances for above or below normal precipitation and a slight chance for above normal temperatures. El Niño is expected to transition to La Niña by the middle of summer. This may cause warmer conditions, but there is not a strong signal for determining precipitation chances.
