November and Winter Weather Outlooks for 2021

October 25, 2021 3:27 PM
Blog Post

The November and the meteorological winter (December-January-February) temperature and precipitation outlooks were recently released by NOAA’s Climate Prediction Center (CPC). Below is a recap of what those outlooks are predicting and the potential impacts those outlooks could have on agriculture.

November weather outlook

The initial November climatological outlooks issued by the CPC do not give clear guidance in terms of temperature and precipitation expectations for Iowa; there are Equal Chances (EC) of above, below or near-average temperatures and precipitation. When EC is present, there is a 34% chance of climatologically expected behavior with above and below-normal behavior each having a 33% chance of occurring.

Winter weather outlook

The Winter 2021-2022 climatological outlooks from CPC exhibit a classic La Niña pattern with elevated chances of wetter conditions across the Great Lakes/Ohio Valley and Pacific Northwest along with colder than average temperatures from Minnesota to the northwest coast. Much of the southern United States has higher probabilities of warmer and drier conditions. For the meteorological winter months of December-January-February, there is an elevated probability of both warmer and wetter conditions in eastern Iowa with Equal Chances (EC) of above/below/near-average conditions for the rest of Iowa.  The increases in temperature and precipitation probabilities across the state are fairly small.  Other (less forecastable) factors can play a larger shorter-term influence in the winter outlooks.

Source: NOAA Climate Prediction Center.

Source: NOAA Climate Prediction Center.

As a reminder, the La Niña phase was also present last winter. Iowa experienced slightly cooler and drier conditions (0.9 degrees/0.49" below normal). The state also had the 12th snowiest winter in 134 years, with 32.2 inches of snow, 9.4 inches above average. It should be noted that precipitation behavior during a La Niña winter is highly variable as opposed to when the El Niño phase is present.

Weather impacts on agriculture

Currently drought conditions have eased a bit but are still prevalent and worst across the central part of the state.  Soil moisture conditions have generally improved to some areas being too wet across northern and southern parts of the state. There is some additional time for more soil moisture recharge before soil freezing in the drier parts of the state.  Draining and soil surface drying in the wet areas will also occur before freeze-up. Warm air temperatures have kept soil temperatures fairly warm.  Freezing soils are still several weeks off given current conditions and expected temperatures. Looking further out, spring planting could be a bit of a problem in those already wet areas, pending what happens with winter precipitation.