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Where did La Nina go? It was forecast to develop this summer, but through late July, it had not come to fruition. Cold water sits quietly beneath the surface in the eastern tropical Pacific Ocean, about 25 meters down, where it cannot affect the atmosphere. But, it could break loose in an instant, causing rapid changes to global weather patterns. By the time you read this, perhaps that has already happened.

But, if not, the forecast is still for La Nina to develop and peak in the fall, gradually waning toward neutral again over the winter into spring 2025. La Nina has happened following every strong El Nino the winter before, as was the case in 2023-2024, when peak anomalies reached 2.0°C (about 35°F) above average. Since the forecast hinges on a phenomenon that has been reluctant to show its face this summer, the following forecast is admittedly a low-confidence one.

PACIFIC NORTHWEST (IDAHO, OREGON and WASHINGTON): Showery and sometimes cold weather moved through the region this summer, inducing frosts in June that caused significant damage to crops. That was followed by heat and dryness into July, and crops have found tough conditions. The increasing heat later this summer is leading to the risk of wildfires going into the fall season. Conditions during the fall will likely be mixed, and potential for increased precipitation late in the fall could keep the wildfire season from being too dramatic. It could also help to build in some soil moisture ahead of winter.

SOUTHWEST: Monsoon showers arrived early in the Four Corners area this summer, knocking back drought conditions. But, the showers have had a hard time expanding westward, leaving California and Nevada drier with reduced soil moisture. Heat has been a big factor, as well, and drought is expanding. Mixed conditions are expected this fall, and we could see an increase in precipitation later in the season. That would be helpful to tame wildfires. But, La Nina typically leaves this region drier in the winter, so that period of increased moisture may be limited.

NORTHERN PLAINS: Variable conditions over the summer have kept the region teetering on the edge of drought. Unfortunately for this region, it started to get hot and dry for the second half of summer, and that may be a common occurrence for the fall season, as well. One caveat to that, though, is that during a developing La Nina, there is an elevated risk for an early cold spell, which may mean an early frost in October before corn has had a chance to finish filling. We saw that in both 2012 and 2020, two years that are high on DTN's list of analog years.

CENTRAL AND SOUTHERN PLAINS: The active spring pattern continued throughout much of the summer, as well, leading to limited drought and overall good conditions for growing corn and soybeans in most areas, especially for those that irrigate. An increase in severe weather may have put a damper on some fields, though. Fall seasons under a developing La Nina are typically hotter and drier for this region, good for drying out a maturing crop and harvest but may cause those who need hay to look elsewhere. And, the establishment of winter wheat could be in some drier fields, as well.

COASTAL TEXAS AND LOUISIANA: A couple of close calls from tropical storms in June led to increased rain in southern Texas, which was followed by Hurricane Beryl's heavy rain in July. Frequent fronts also helped to maintain adequate to surplus moisture in the region, at least going into August. However, La Ninas leave the southern tier of the country drier in the fall and winter, and we could see drought developing throughout the season. The caveat again would be the potential for more tropical storms to affect the region.

MIDWEST: An active spring turned into a mostly active summer, as well. Drought briefly popped up in the east but was eliminated in July because of the remnants of Hurricane Beryl and bouts of heavy thunderstorms. The rain was not welcomed in the northwest -- which has had major issues with wetness all season -- but was in most other areas. Thunderstorms have also led to an increase in severe weather, including a derecho reminiscent of 2020 in mid-July. Thankfully, this year's system was not as severe and came a month earlier, giving crops a chance to recover. Falls during La Nina tend to be warmer and drier, a good prospect for maturing corn and soybeans, as well as harvest.

DELTA/LOWER MISSISSIPPI VALLEY: Conditions were variable this summer with stretches of hot and dry conditions juxtaposed with bouts of milder and rainier ones. Depending on timing of crop development, that could have been a good thing or a bad thing for the region. La Nina typically leaves this region hotter and drier in the fall, which would be better for harvest and fieldwork. But, a potential visit from tropical storms also increases early in the season, which could be a cause for concern, as well.

MID-ATLANTIC AND NORTHEAST: Despite active weather in other parts of the country, including the Northeast, the Mid-Atlantic saw long stretches of above-normal temperatures with little rainfall, enough to cause widespread, temporary but significant drought during the middle of the season. Conditions started to improve in mid-July but might have been too late for some. Unlike most of the rest of the country, falls during La Nina can be more active, and the drought that remains may be eliminated. Tropical storms in the Atlantic will also need to be watched, as they have a higher chance of landfall.

SOUTHEAST: The region went through a long stretch of hot and dry weather this summer, which caused temporary but significant drought. Relief came later in the summer, but some crops were damaged anyway. And, that came to a head when Hurricane Debby and its remnants moved through Florida and up the coast, causing a lot of flood damage. La Nina typically leaves this region drier during the fall; but eyes will still be on the tropics, which have an expectation of being active this fall and could cause wide swaths of heavy rain should they affect the region.

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-- Read John's weather blog at https://www.dtnpf.com/…

-- You may email John at john.baranick@dtn.com

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