Spring Weather Outlook and Beyond

Spring Weather Outlook and Beyond

Written by: Eric Snodgrass, Principal Atmospheric Scientist Nutrien Ag Solutions

The 2021 growing season was dry across much of Minnesota and North Dakota while the state of Wisconsin largely saw adequate moisture. Given the drought conditions witnessed last year, many farmers and ranchers are wondering what will be in store for 2022. Let’s take a look at recent weather modeling to help piece together what may be coming our way.

South America

Our 2022 late-winter weather outlook starts in South America where despite the rapid planting of the first crop of soybeans in October and November, extensive drought developed across Southern Brazil, Paraguay, Uruguay, and Argentina. Temperatures hit triple digits several days in a row in Argentina with very little rain in December and early January, while Southern Brazil received less than half of its normal mid-season rain. Mato Grosso, Brazil’s largest ag state (30% of total production), had nearly ideal weather but could not make up for the yield loss in Mato Grosso Do Sul, Parana, and Rio Grande Do Sul. The result has been a roughly 20 MMT reduction in total soybean production for the 2021-22 growing season.

Safrinha corn planting (about 75% of Brazil’s total corn production) is ahead of the five-year average planting pace, but mid- to late-February has been very dry in Southern Brazil, while heavy rains have slowed the planting pace in northeastern Brazil (20% of the growing area). The result is that total ag productivity across South America moving through March and April is neutral to lower.

There is concern, given the La Niña and the behavior of the Madden Julian Oscillation (MJO), that the South American monsoon may slow down earlier than normal putting some of the safrinha crop at risk of finishing in drier than normal conditions. Figure 1 shows the European Centre for Medium-Range Weather Forecasts (ECMWF) forecast for rainfall anomalies March – May 2022.

Figure 1 Precipitation Anomalies forecast for March – May 2022 by the ECMWF Seasonal Forecast Model. Source: ECM- WF and https://www.weatherbell.com

La Niña

The colder water that stretches between South America and the central Pacific Ocean shown in Figure 2 represents the current state of La Niña. This is the second La Niña winter in a row and nearly all forecast models show the La Niña fading toward neutral conditions by late Spring. We care about the behavior of the ocean temperatures and trade winds in the Pacific because these two variables impact the position and strength of the jet stream as it travels across North America.

While the ocean temperatures along the equatorial Pacific slowly fade back to normal, we must keep a close eye on the colder water in the Gulf of Alaska. The cold water in this region is part of a long-term cycle in ocean temperature in north Pacific called Pacific Decadal Oscillation. The last time the waters were this cold in the Gulf of Alaska was during the 2008 – 2013. The concern is over the extent and depth of that cold water going into the 2022 growing season. If the cold water expands south toward the California coast over the next three months, the risk for summer drought increases in the upper Midwest. Six out of 10 years where the water is very cold all along the west coast of North America, the Midwest experiences drought. Most long-range models do not expand this region of cold water through mid-summer – which is a very good sign – but we need to monitor this very closely.

Figure 2 Current Sea Surface Temperature Anomalies on Feb 14, 2022. Source: https://coralreefwatch.noaa.gov/data_ current/5km/v3.1_op/daily/png/ct5km_ssta_v3.1_global_current.png

Current Snowpack and Spring Flooding Outlook

This winter has not delivered uniform snowpack across Minnesota, North Dakota, and Wisconsin. The top of Figure 3 shows the current snowpack (in liquid equivalent) through February 15. Notice how the headwaters of the Mississippi River and the Red River have between two to eight inches of meltwater in the snowpack, but much of the Western Plains is snow-free (especially on the Missouri River).

The bottom of Figure 3 shows seasonal snowfall anomalies through February 15, 2022. A large region from Southern Wisconsin through the

Figure 3 Snow Water Equivalent (inches) valid on Feb 15, 2022. Bottom: Seasonal snowfall anomalies (% of normal) through Feb 15, 2022. Source: https://www.nohrsc. noaa.gov/nsa/

Western Cornbelt has been repeatedly missed by big winter storms since November. We need to monitor the March and April forecast closely for the jet stream to move into a position that flows out of the southwest across the Western Cornbelt to relieve the expanding drought in that area.

Figure 4 NASA 0-40cm (16”) Soil Moisture Percentile valid on Feb 15, 2022. Source: https://weather.msfc.nasa. gov/sport/case_studies/lis_CONUS.html Bottom: US Drought Monitor for Feb 10, 2022 Source: https:// droughtmonitor.unl.edu/

March 2022 Forecast

The forecast through March 2022 (shown in Figure 5) indicates above normal precipitation for most of the Mississippi Watershed, which could increase the flood threat along the Mississippi and its tributaries if the forecast verifies. Better rains are also forecast for Northern California and the Pacific Northwest, but models are not overly ambitious on significant drought relief in the Plains. Expect a volatile temperature pattern through March, which is typical for the Upper Midwest in late winter. One very good thing about the late winter is that the

Figure 5 ECMWF Forecast for March 2022 Precipitation Anomalies. (Source: ECMWF and https://www.weatherbell. com)

Polar Vortex is very strong, which limits the duration and depth of Arctic outbreaks of colder air.

Spring and Summer Outlook from the ECMWF and NMME

The long-range precipitation forecast for Spring (April-June) and Summer (June-August) is shown in the four-panel plot in Figure 6. Forecast models have consistently called for above average spring rains east of the Mississippi throughout the Great Lakes. This is largely due to the models building the area of the current drought in the Plains. Confidence is low in this forecast because of the highly variable behavior of the Pacific jet stream this winter. The ECMWF is favoring slightly above average temperatures, but we cannot use this analysis to predict the timing of the last frost of Spring.

Nearly all long-range forecasts for Summer 2022 build drought in the Central Plains. This is common model behavior when there is drought in the Plains to expand it through Spring and Summer. Last spring, the drought area in the Southern Plains recovered quickly, while drought expanded throughout the Western Cornbelt into the Canadian Prairie and the whole of the Western U.S. If the drought area increases in size this Spring for the Plains, it could possibly increase the thunderstorm activity across the Upper Midwest this summer.

In summary, the drought risk for the primary corn and soybean belt is elevated above average given the fading La Niña, colder water in the Gulf of Alaska, and current drought issues. The historical average for “significant” drought risk (defined as drought that reduces yield more than 20% below trend) is 30% going into any growing season. The risk this year is currently 38%.

Figure 6 ECMWF Seasonal Forecast Guidance (Source: ECMWF and https://www.weatherbell.com). Top Left: April – June Precipitation Anomalies (inches). Top Right: April – June Temperature Anomalies (°C). Bottom Left: June – August Precipitation Anomalies (inches). Bottom Right: June – August Temperature Anomalies (°C)