Drought patterns are difficult to break

As I’ve mentioned in previous articles, the western portion of the country, especially the Southwest, has been in a long-term mega-drought pattern. With the super El Nino in the waters of the Pacific Ocean, there has been a slight increase in moisture across Southern California with heavier rains in the Desert Southwest. However, here in the Inland Northwest, it’s still much drier than normal.

At Cliff Harris’s station in Coeur d’Alene, only 0.05 inches of rain has fallen this month, compared to a normal of 2.22 inches for October. According to the U.S. Drought Monitor, most of northeastern Washington and northern Idaho continues to experience severe to extreme drought conditions. In fact, the extreme drought category covers sections of Spokane and Kootenai Counties.

The normal precipitation for Coeur d’Alene during an entire year is 26.77 inches. So far, only 11.34 inches has fallen. It was drier at this time last year with slightly under 10 inches of rain and melted snow. By the way, the skies opened up in early December as 2025 finished with 19.34 inches of moisture in Coeur d’Alene. As we’ve mentioned in previous articles, the driest calendar year in Coeur d’Alene’s history occurred in 1929 with 15.18 inches. The latest forecast has our final moisture total at around 20 inches, but with this El Nino and drought pattern we’re in, it could stay dry.

Extended drought conditions are one of the most persistent and complex forms of extreme weather. Unlike a flood or severe thunderstorm, which can develop and disappear within hours or days, a region experiencing a drought can continue for months or even years. Once this pattern becomes established, numerous processes can reinforce the dry conditions. Below-normal precipitation, depleted soil moisture, high temperatures, reduced snowpack, persistent atmospheric patterns, and changes in vegetation can all contribute to making a drought difficult to break, especially in the lower latitudes.

One of the most important factors is persistent atmospheric circulation. Large areas of high atmospheric pressure can become established over a region and remain in place for an extended period of time. High pressure generally causes air to sink, which suppresses cloud development and precipitation. It can also redirect storm systems away or substantially weaken them when they close to the area affected by drought.

Dry soils can also create additional issues. Normally, water in the soil evaporates into the atmosphere, providing moisture that can contribute to cloud formation. During drought conditions, soils become increasingly dry and ultimately reduces evaporation. With less moisture, there may be less water available for clouds and precipitation. At the same time, dry ground can heat more rapidly during the day, often leading to higher temperatures, making drought conditions more difficult to break.

Ocean temperatures can also influence drought persistence. Large-scale ocean-atmosphere patterns such as the warmer El Nino and cooler La Nina can alter the position and strength of atmospheric circulation and storm tracks. During the La Nina years, we often experienced above normal moisture and snowfall. There were many years in the 2000’s and 2010’s where moisture was above average in North Idaho. For much of the 2020’s, conditions have changed where annual precipitation totals have been near to below normal. During the 2000’s, ocean waters near the West Coast was mostly cooler than average levels. However, in recent years, sea-surface temperatures in the same region have warmed up. As a result, the recent weather patterns have shown the low pressure systems much farther offshore with a high pressure ridge over the western U.S.

One major rainfall event does not necessarily end a drought. For example, September broke the trend of dry months across much of the Inland Northwest. A heavy storm or a brief series of storms may temporarily improve surface conditions while deeper soil layers, groundwater, reservoirs, and rivers remain depleted. Ending a long-lasting drought generally requires a sustained period of above-normal precipitation rather than several weeks.

California and other parts of the western U.S. are counting on some kind of drought relief from the current El Nino. Under the new federal framework, California, Arizona and Nevada could all lose up to 3 million acre-feet of water from the Colorado River, which is about 40% of their supply per year. One acre-foot, a unit denoting the amount of water that can cover a football field one foot deep and is equal to roughly 326,000 gallons. This is enough to supply roughly three families for a year.

Over the last 20 years, our region has seen many instances of going from drought to floods. If El Nino peaks late this year, conditions could change drastically by early 2027. In the meantime, the long-range computer models are pointing to an increase in moisture across the region later this week and into early November. Perhaps we’ll have a repeat of last year with above normal either next month or in early December, especially if some tropical moisture moves northward into the area. Stay tuned.

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Contact Randy Mann at [email protected].