Program Evaluations

Since the start of weather modification regulation in 1975, a number of evaluations have been made of the effects of the program. These evaluations have been based on a variety of differing data bases. Among them are: ARBCON rainfall data, National Weather Service (NWS) rainfall data, crop hail insurance data compiled by the National Crop Insurance Service (NCIS), and wheat yield data compiled by North Dakota State University.

Computer-based numerical models have also played an important role. Economic models have provided estimates of the economic benefits of the program, while cloud models have produced increased insights into the complex processes within the clouds that ultimately govern hail and rain production. All of these evaluations have been independent, that is to say, they've been done by agencies and universities unaffiliated with the DWR, allowing the best qualified persons to do the evaluations, improving the chances for an unbiased, solid, scientific approach.

As of this date, all evaluations of the program have shown either positive or neutral results. No suggestions have been found of negative impacts, either within or outside target areas.

Crop Yields and Improved Loss Ratios

Image of a wheat field.

Michigan State University Professor Dr. Mark Skidmore and Graduate Student Scott Knowles recently evaluated the North Dakota Cloud Modification Project (NDCMP) and its effects on crop yields. Using 30 years of United State Department of Agriculture (USDA) Risk Management Agency data, their analysis sought to determine if there was any difference in crop yields (wheat and barley) and insurance loss ratios for NDCMP project counties versus surrounding counties not involved in the program.

For the 1989-2018 period, they found that average annual wheat yields in seeded counties were 13 percent higher than wheat yields in non-seeded counties. In the words of the authors, “Our evaluation indicates that the cloud seeding program had significant positive effects on crop yields and improved loss ratios.” A further analysis of economic benefits found a benefit to cost ratio of more than 36 to 1.

If you would like to read this study, you can find it at the website for the American Meteorological Society journal Weather, Climate, and Society.

Crop Hail Evaluation

Image of a corn field.
Several evaluations have helped show the effects of cloud seeding for hail suppression in North Dakota. Primarily through the analysis of crop insurance data, studies have found a reduction of crop-hail losses up to 45 percent in the seeded areas versus unseeded upwind control areas. (Read Full Article)

Economic Impact of Reducing Hail and Enhancing Rainfall in North Dakota

Image of a cloud seeding aircraft parked on the tarmac with a rainbow in the background.
A recent study from the North Dakota State University (NDSU) Department of Agribusiness and Applied Economics (Bangsund and Hodur, 2019) describes the significant economic benefits cloud seeding provides to agricultural production in the western North Dakota counties of Bowman, McKenzie, Mountrail, part of Slope, Ward and Williams. (Read Full Article)

Rainfall Evaluations

Image of a cloud seeding aircraft, flying under a cloud with their cloud seeding generators on.
Cloud seeding effects on rainfall have been evaluated by several independent scientists using numerous datasets. Results of the studies indicate precipitation increases in and downwind of the seeded areas in percentage amounts ranging from the low single digits to the low teens, with typical results falling in the 5-10 percent range. (Read Full Article)

Urban Effects

Image of a water tower with a winking face.
The effects of cloud seeding on urban areas in North Dakota have not been quantified. (Read Full Article)

Wheat Yield Study

Image of a combine in a field at sunset.
While evaluations that quantify precipitation or hailfall are certainly useful, the “bottom line” for the county-sponsored NDCMP is what effects are found in crop yields. (Read Full Article)

References

Image of a cumulonimbus cloud on the horizon.
View all of the references used in the above articles along with links to the publications. (View Full List Of References)