On May 28th, the latest Grass-Cast forecast maps were released (below). As was discussed in Livestock Wx’s article this week on the Grass-Cast system (In its Second Year Grass-Cast Continues to Improve: See What’s New in 2019) the grass production forecast maps are based on the June-July-August Precipitation Seasonal Outlook released by NOAA on May 16th. (map at right)
The precipitation seasonal outlook from NOAA indicates the odds are tilted in favor of a wet, or above-average June-July-August for most of the Great Plains. Most of Wyoming, and parts of Nebraska, and Colorado have the highest odds of a wet summer. As a result, the Grass-Cast Forecast is favoring an Above-Normal Precip scenario (left map above) which could translate in forage production across the Great Plains of 15-30%, or more, above what would normally be produced (based on production estimates averaged between 1981-2018) by the end of August.
What does above -average precipitation mean, though, and how does it compare to annual forage production? We break this down below in the hope that you can track precipitation in your area and how that fits in with what you would normally receive based on the last 30-years of precipitation information.
The below interactive charts show average forage production in lbs/acre/yr compared to the total amount of precipitation (averaged from 1981-2010) for each county the Grass-Cast Forecast covers. Use your mouse to see individual values for your specific county. Knowing average precipitation totals for summer will help interpret NOAA’s Seasonal Outlook and just what Above-Normal (i.e. average) means. For example, Woodward County in Oklahoma normally receives over 8″ of rainfall during the summer and has an estimated average forage production of over 1,300 lbs/acre/yr. This year Grass-Cast is forecasting a 30% increase, or about 1,700 lbs/acre/yr.
The question, though, is will Woodward actually get “Above-Average” or greater than 8″ of rainfall this summer?
The below interactive chart shows how much precipitation has been observed in the first few days of June (actually goes from May 28-June 4th) vs how that corresponds to what is expected for the entire summer (middle chart). The third chart shows the percentage of cattle in each county by that state’s total number of cattle. Using Woodward Oklahoma as the example again, they have already received about 1.5″ of rainfall in the last few days. Not bad at all and a great start to the summer.
Let’s hope NOAA got their Outlook right and that we will continue to have good summer precipitation. Of course for those areas that have been flooding, we hope it comes a little at a time!