Ag Weather Forum

While some things have become clearer regarding the short-term forecast for the United States going into spring, there are still loads of questions hanging over the country to start the season.

There are many concerns about the conditions across the country. With drought in the Southwest, Plains, and Upper Midwest, along with flooding in the Ohio and Lower Mississippi valleys, there aren't many sweet spots that have a good outlook for planting and early growth.

With La Nina fading into the summer, many questions are arising for the summer and how heat and dryness may make develop.

However, these are some of the main things expected:

-- La Nina is fading toward neutral but will affect the forecast for a while.

-- The spring pattern is in flux, with problems likely during planting and early growth.

-- Historical cold-neutral ENSO favors stagnant patterns during summer.

The following goes into more detail on these points and is an update to the earlier seasonal forecast issued back in mid-January. You can find that forecast here: https://www.dtnpf.com/….

LA NINA IMPACT ON THE FORECAST FOR A WHILE

The El Nino Southern Oscillation (ENSO) took a brief dip into the La Nina category in late December and peaked in late January and early February. Sea-surface temperatures since have been rising in the eastern Pacific Ocean for the past couple of weeks, though temperatures in the central Pacific are firmly low enough to be considered in a La Nina state. In fact, the waters just off the coast of South America are more indicative of an El Nino rather than a La Nina. Several factors have contributed to the warming, but the fact remains that the La Nina from winter is fading heading into spring.

Neutral conditions are somewhat of a misnomer, because being on either side of the average temperature line can lead to pattern changes for the U.S. during spring and summer. While not technically a La Nina, even below-normal sea-surface temperatures can lead to stagnant weather patterns, particularly in summer. The warm side of neutral can lead to the opposite, a more-active weather pattern that tends to favor fewer swings in extreme temperatures and more storm systems moving through.

Therefore, ENSO's character will still provide the basis for the forecast this spring and summer, guiding the overall patterns we are likely to see.

The problem is models have a large spread in how the ocean temperatures will respond during the next few months. It is typical during this time of year for forecasts to have a large spread. The so-called "spring predictability barrier" has been used by meteorologists and climatologists to refer to the lower accuracy of global models in predicting ocean temperatures, especially with regard to ENSO, during the Northern Hemisphere spring. Now that we are heading into March, we are fully into that time of reduced predictability.

But there are some hints that can help us decide which side of neutral ocean temperatures may be. Looking deep beneath the surface of the ocean lurks a large pocket of cold water that could keep surface temperatures down a bit. It is not guaranteed to do so, but that would be the potential for keeping below-normal temperatures around later into the year.

History also suggests the colder side of neutral would be preferred, and even indicates La Nina will likely develop again in the fall or winter. In the winter of 2023-24, ENSO was in a very strong El Nino, what some meteorologists refer to as a "super El Nino". Ocean temperature readings peaked out at 2.0 degrees Celsius above normal, a feat that has been accomplished five times prior in data going back to 1950. When looking back at those "super El Ninos," an interesting turn takes place. Because for the following two winters, La Nina was found in each case. Since we're already going through the first La Nina, a second is likely to redevelop this coming winter. Staying on the cold side of neutral would help to see that scenario play out.

Therefore, DTN prefers the cold side of neutral in its seasonal forecast going through the fall season.

PROBLEMS LIKELY DURING PLANTING, EARLY GROWTH

La Nina's fading away makes a base-state less likely and encourages movement of weather systems during the spring.

The pattern may stay active, but colder air tends to win out across the north, leading to a winter hangover into late March and April. Indeed, there are other signals besides this historical factor that point toward cooler conditions infiltrating the north during this time. That could mean a slower warmup in soil and delay planting.

Dry weather in the Western Corn Belt is likely to have an impact as well. Drought already exists across much of the Corn Belt from the Mississippi River westward. Some extreme drought exists in pockets of the Northern Plains, traditionally more wheat and forage country than corn or soybeans. But elsewhere, soil moisture is low and drought is growing. From Kansas and Nebraska into Illinois, Indiana, and Ohio (away from the Ohio River), long-term precipitation deficits are large.

You can read more about the potential impacts of this from DTN Ag Meteorologist Emeritus Bryce Anderson here: https://www.dtnpf.com/….

Residual snowpack from the winter is also lacking. Very little exists, mainly over the far north from Montana to northern Wisconsin and across Michigan instead of being from Nebraska to Ohio. The lack of moisture may help planting be done in a timely fashion but would restrict early growth and set the stage for a stressful summer.

The Eastern Corn Belt is favored with a more active storm track. With wetter conditions the last couple of months from the southeastern Plains through the Ohio and Tennessee valleys, additional rain could put these areas at risk of later plantings due to wetness. Lower temperatures up north may bleed into these areas at times, with slower rises in soil temperatures pushing back planting as well.

STICKY PATTERNS DURING SUMMER

With the cold-neutral ENSO as the basis of our forecast, that points to some rather interesting weather for the summer, too.

By the time we get to May, the pattern may flip abruptly, getting into the summer season rather quickly, and building heat. The cold side of ENSO tends to favor slow-changing patterns during the summer season. Once a pattern emerges, it sticks around for weeks.

The DTN forecast shows a lot of heat from May through September but favors areas west of the Mississippi River each month. Eastern areas are less likely to experience long stretches of heat, but they can be possible and will likely occur at times as well.

Precipitation is preferred in the far Eastern Corn Belt and East Coast and may include the Southeast from time to time as well. But the Western Corn Belt and Plains are forecast to receive much less precipitation than we would expect during a summer season.

With the spring season also dry, the potential for Western Corn Belt and Plains farmers having to deal with heat and dryness during the summer is increased, as is the stress potential. In the Eastern Corn Balt and Southeast, the stress may not be as intense as farther west, but stagnant patterns could produce stressful conditions during inopportune times for crop development.

That stagnant pattern will be favored throughout the summer, but it doesn't mean it will be constant. Regardless of ENSO, changes to the pattern will occur, and timing will be important. If the pattern becomes cooler and wetter in July, the previous heat and dryness may not matter as much if the weather is favorable for pollinating corn and blooming soybeans. If that continues into at least portions of August, filling corn and soybeans would benefit greatly.

STILL PLENTY OF UNCERTAINTY

With the spring predictability barrier not giving meteorologists an easy time with the overall forecast, we are relying on history quite a bit. And as everyone probably knows, no two years are the same. What looks like a hot and dry pattern may not turn out to be for everyone in those zones. Some areas may get just the right amount of rain at just the right time to overcome the overall hot and dry conditions. And even the opposite can be true. Areas in the East that have a more favorable forecast, may run into stretches of heat and dryness at the wrong time.

Severe weather and hurricanes are always a threat and are unpredictable. So, even though the forecast does not look like a favorable one right now, what actually happens during the spring and summer will be more important than a late-February forecast.

To find more weather conditions and your local forecast from DTN, head over to https://www.dtnpf.com/…

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

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