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A month without moisture in the Inland Northwest

| August 10, 2020 1:05 AM

After 30 days of rainless weather in Coeur d’Alene and surrounding regions, we finally received some measurable moisture last Thursday. However, amounts were very light as Cliff measured just .04 inches at his station. Spokane only measured .02 inches with Hayden and Post Falls picking up .05 inches. Prior to the dry spell, the last time we had any measurable rainfall was on July 7 as .32 inches fell on that day. Also, during the 30 days without rain, we were drier than parts of the Sahara Desert.

According to Cliff’s records, there were only three other years when Coeur d’Alene went 30 days without any measurable moisture at this time of year. Despite the drier-than-normal weather, we still have a healthy moisture total for 2020. So far, Cliff’s station has received 18.25 inches of moisture compared to a normal of 15.19 inches.

The drier-than-normal weather pattern has led to widespread drought conditions across much of the far West. In fact, over one-third of the U.S. is currently experiencing abnormally dry to extreme drought. According to the U.S. Drought Monitor, the driest areas are across parts of southern Utah, southern and eastern Colorado, southeastern New Mexico and northwestern Texas. Some of that dryness has recently expanded into western Iowa.

Here in the Inland Northwest, extreme northwestern Montana has been rated as abnormally dry, but the Spokane and Coeur d’Alene areas are still within normal moisture ranges. However, much of central Washington is experiencing severe drought conditions.

The lack of rainfall in the Far West has also led to numerous wildfires. As of late last week, the National Interagency Fire Center reports that there were over 40 large blazes that were consuming close to 300,000 acres. Most of the fires are in California with 10. Alaska was reporting seven large blazes and Washington and Idaho both had one wildfire.

We don’t see much moisture until we get toward the middle to the end of this month. The normal precipitation for August is 1.23 inches, and our area could end up close to that figure as it looks like the big high pressure system that’s been locked in over North Idaho will finally start to weaken.

The chances are getting higher that our upcoming fall season will turn wetter and cooler than normal. Sea-surface temperatures have been cooling over the last month along the Equatorial regions in the south-central Pacific Ocean. This stretch of cooler waters along the Equator are about 1-3 degrees below normal near the South American coastline. It looked like ocean temperatures were starting to moderate last month, but the latest data does show a trend toward cooling.

Although, ocean waters along the Equator have been going down, based on the current data, we are currently in-between the cooler La Nina and warmer El Nino event, which we often call a “La Nada.” According to the Australian Bureau of Meteorology, one of the world’s leading forecasting entities that closely monitors sea-surface temperatures, about half of the computer models that forecast sea-surface temperatures are still indicating that we may indeed see a new La Nina in early-to-mid fall. They have recently raised their outlook to a “La Nina Watch,” meaning that the odds have increased to 50 percent that a new La Nina will form. The forecasters also mentioned that cooling of ocean waters has occurred beneath the surface of the equatorial Pacific Ocean, which is another indicator that we may see a new El Nino in the coming months.

The Climate Prediction Center in the U.S. also favors a La Nada for the rest of the summer season, but close to a 50 percent chance of a new La Nina this fall as well.

With the current sea-surface temperature pattern, we’re also expecting to see a very active normal tropical storm and hurricane season as ocean waters off the coast of Africa are also warmer than normal, where many of the systems originate. There have already been nine named storms and we’re predicting at least 20 named systems developing in the Atlantic and Caribbean regions. Some forecasters are saying that we could see close to 25 named storms.

Also, sunspot activity remains very low, but not like last year when there were very few or no sunspots being observed. This solar pattern is expected to continue into 2021, then solar storms should start to increase as we head toward a new solar “maxima” cycle around the mid-2020s. If ocean temperatures do indeed turn much cooler later this year, then there is a good chance we could have above-normal snowfalls across Coeur d’Alene and the rest of the Inland Northwest as well as the northern portions of the country during the winter of 2020-21. Some Russian forecasters are calling for a rough winter across the Northern Hemisphere. Stay tuned.

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Contact Randy Mann at randy@longrangeweather.com