March more or less came in and went out like a lion. The below normal temperature trend we experienced in February continued through March, averaging 5.2 F below normal. Western and southern Iowa experienced wetter than average conditions in March while the rest of the state experienced below average. Consequently, the preliminary observations have March precipitation at 0.10 inches below normal across the state. March 2019 was the 30th coldest March on record and the 58th wettest in 147 years of statewide observational records.
Figure 1. Precipitation (in.) departure from the mean from March 9 to April 7, 2019 shows western and southern Iowa above average and the rest of the state below average (Source: https://mrcc.illinois.edu/state_climatologists/iowa/prcpdev-30days.png).
Western Iowa, eastern Nebraska and part of South Dakota experienced devastating floods following the “bomb cyclone” that came through in March. More flooding could be experienced in Iowa, particularly in eastern Iowa (Figure 2). Parts of northern Minnesota still have 1 to 6 inches of water equivalent of snow on the ground that needs to melt, which will eventually makes its way down to the Mississippi. This is why the predications for eastern Iowa are higher compared to other parts of the state.
Figure 2. Projections from the National weather service of locations with 50% or greater chance flooding could be experienced during April, May, and June (Source: https://water.weather.gov/ahps/region_long_range.php?state=ia&percent=50#)
As we look towards #plant19, we want to be thinking about field conditions for spring fieldwork. Looking at the weather outlook, the 3-4 week outlook favors above normal temperatures with equal chances for above, below, or climatologically normal precipitation. The 6-10 day outlook indicates more normal precipitation.
Soil temperatures are starting to warm-up. On April 7, soil temperatures at the 4” depth crossed the 50 F mark. While soil temperatures are one component to consider, we also need to consider whether field conditions are suitable for fieldwork. According to the National Weather Service Climate Prediction Center, many of Iowa’s fields are in the 99th percentile for soil moisture as of April 8. With wet soil conditions, this could create some challenges with getting field work completed. Check out this ICM News article, "Spring planting and wet soil management" for ideas on how to manage the wet soil conditions in fields this spring. For farmers who have experienced flooding in fields, check out this ICM News article, “Management Considerations for Post Flooding Soils.”
Given the current wet soil conditions and the lesser chances for dry conditions, #plant19 could present some challenges. We are still on the early side of the ideal planting window in Iowa as it is recommended to plant corn from mid-April to early May to achieve the highest potential yield; however it will be important to evaluate conditions field by field.
Figure 3. Corn planting window to achieve 98% yield potential (Corn and Soybean Field Guide, IPM 0001, 2016).
Additional resource: Iowa Preliminary March Monthly Summary
By: Justin Glisan, State Climatologist for Iowa and Dennis Todey, Director of Midwest Climate Hub