Ag Weather Forum

A stable upper air pattern has set up recently with a ridge building across the country. Typically, this means hot and dry weather, but that was not the case last week. Systems moved through the Northern Plains, dropping several periods of moderate to heavy precipitation. Dry sections in the Dakotas received more than 2 inches of precipitation, totaling almost a month's worth of rainfall in a couple of days. The dryness and drought have almost "washed away" in the western Dakotas. The much-needed rainfall did come with some flooding, however, but prospects for spring wheat and corn improved in these areas.

Another weakness in the ridge came in the Southeast where a mid-level system has been churning for the past week. This has brought substantial rainfall to most of the region, including portions of the Delta and southern Midwest, where dryness had been starting to cause concern. Again, flooding was an issue, but the rainfall generated better prospects for crops.

Heat and humidity in the Plains also brought periods of showers, including western Texas, where drought has caused cotton condition to fall. Showers were not enough to eliminate the concern, but at least keep it from getting worse for the time-being.

Not all areas were as lucky. Drier sections in the eastern Midwest saw some isolated showers, but amounts were generally on the order of 0.50 inch or less where they occurred, and evapotranspiration quickly ate through any appreciable rainfall that fell. Corn condition dropped at least a few points in Illinois (6 points) and Indiana (3 points), and significantly in Michigan (10 points) and Ohio (10 points) with similar drops in soybean condition as well. But overall conditions did not change much across the country, due to slight rises in the Western Corn Belt and Delta.

The ridge will remain firm, especially over the west, over the course of the next week. A tropical system may form in the Southeast later this week and track up the East Coast. Meanwhile, a couple of disturbances will move along the rim of the ridge across the northern tier of the country, producing periods of showers. This will be especially welcome to the drier Eastern Corn Belt where rainfall amounts of 1-2 inches are generally expected July 10-12. Showers will be scattered, but the prospect of showers will offer some easing of crop stress. Areas in the Central and Southern Plains will largely be missed, though some thunderstorm complexes may move through eastern Nebraska and Kansas. The ridge will not be kind to cotton producers in western Texas and adjacent areas in the southwestern Plains. Very little prospect for rainfall and building heat will continue to stress developing cotton and put a strain on irrigation.

In the Pacific Ocean, La Nina development continues to be slow. Equatorial Pacific temperatures actually rose during the past week to minus 0.1 degrees Celsius, after lingering near the La Nina threshold value of minus 0.5 degree C for the past few weeks. Warming in the western portions of the region offset the recent cooling. This break is forecast to be short-lived and a return to temperatures near the La Nina threshold should show up again in the next week or two. The Pacific temperature pattern will continue to be closely monitored as we continue through the summer.

John Baranick can be reached at john.baranick@dtn.com

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