New NOAA Long-lead Forecasts Wipe-out Much of U.S. Drought East of Divide
09/17/2026, 1:52 pm EDT
Climate Impact Company Sunday Agriculture Report
Issued: Sunday, September 20, 2026
Highlight: Great Plains are mostly wet, 11-15-day forecast appears cooler. Southern Brazil rains/changeable temperature across South America.
Fig. 1: The 12Z ECM MAXRES 15-day rainfall amount forecast for the U.S> AG Belt.
Discussion: The consensus of most forecast models is rainy periods across much of the Great Plains through the next 15 days. ECM MAXRES is wettest in Omaha, NE and vicinity while the far southern Great Plains into Texas are dry (Fig. 1). This week is cool in the U.S. Corn Belt, and utilizing all models, a general warm-up is forecast early next week (Fig. 2). However, a cooler trend appeared in many model run(s) today in the extended-range forecast while 1 or 2 models remain quite swarm.
Fig. 2: SPP (Central U.S.) electric reliability region of the U.S. 15-day average daily population weight temperature forecast.
The 15-day outlooks are consistent with expansive wetter than normal conditions across Southern Brazil and Paraguay with ECM ENS the most aggressive (wet) forecast (Fig. 3). Note that recent rainfall has been abundant through a narrow channel stretching from Northern Chile to central continent to the Brazil Southeast Coast (Fig. 4). Either side of the wet weather very dry conditions have persisted. The 6-10-day forecasts are notably hotter than normal in the 6-10-day period with a potential much cooler change in Argentina during the 11-15-day forecast.
Fig. 3-4: ECM ENS 15-day rainfall anomaly forecast for South America and percent normal rainfall observations for the past week.