State Soil Moisture Update

The Soil Moisture Index (SMI) is based on the estimated field capacity and wilting point at three depths (10 cm, 25 cm, and 50 cm) at Automated Weather Data Network (AWDN) sites under grass cover. The index may not necessarily be representative of conditions of a nearby field, particularly if differences in total precipitation over the previous week have been significant.

Note: Maps link to larger versions.

May 11, 2015

This week the High Plains Regional Climate Center added a new resource on its site: State Soil Moisture Update. Watch CropWatch for regular articles on this topic..

Most of the state had a wet week, with portions of eastern Nebraska receiving 8-9 inches last Wednesday night alone and parts of the Panhandle receiving a soaking followed by snow. The rain (and snow) combined with a lack of heat allowed for significant moistening in many areas. Most of the Panhandle is exceptionally moist, with soil moisture index (SMI) values above 5.0 (which is the index value equivalent to field capacity) over the top 2 feet of the soil profile. Much of eastern Nebraska is also close to or exceeding field capacity, so additional rainfall is not necessarily welcome in that area.

Some areas of central Nebraska have missed out on these weather events and there is a row of stations from Shelton northeast to Grand Island where the SMI is below 0.0, indicating the top 2 feet of soil has less than 50% of its available water capacity. In terms of moisture deficits in the top 2 feet, Minden has the highest amount with a deficit of a little over an inch. In other words, Minden would need an inch of rain with 100% infiltration (which is unlikely) to get back to the break even point.

Most of the state has a good shot at seeing an additional inch this week, including the areas in central Nebraska where soils are a bit on the dry side. Rain in most of eastern Nebraska isn't exactly welcomed right now, but the current forecast isn't showing a repeat of the middle of last week.

Eric Hunt
High Plains Regional Climate Center