Dry August, September usually leads to more snow

We’ve now seen one of the driest combined July, August and September periods in recorded history in Coeur d’Alene and the rest of the Inland Empire. For July, we only had .57 inches of rain, which fell during the first seven days of the month. August only had .12 inches of rain while September was slightly better with .50 inches.

The normal precipitation for July, August and September is 3.63 inches. For those three months, Coeur d’Alene only received 32.7 percent of normal with 1.19 inches. If we take out the first seven days of July, our total rainfall since July 8 was only .62 inches, or 17 percent of normal.

The dry conditions were not only prevalent in the Northwest, but much of the western U.S. as well. As a result, it was another disastrous fire season for the Far West, especially California. We saw record air quality numbers as the smoke pushed many locations well into the hazardous category.

The drier-than-normal weather pattern will continue for much of this week. However, there are indications of change in the upper levels of the atmosphere. As we move into the weekend, it does look like we’ll have an increasing chance of showers across the Pacific Northwest. Around the middle of the month, it’s possible that we could see some flakes of snow in the higher mountains.

Looking back and climatological records since 2005, I discovered that when Coeur d’Alene and other areas have a much drier-than-normal August and September, there is at least one month during the following winter season when we received a lot of snow.

For example, in 2006, there was only .80 inches of rain that fell, compared to an August and September combined normal of 2.71 inches. January and February of 2007 were snowy with a total of nearly 49 inches of snow for the two months.

The following year, 2007, had another dry August and September with 1.43 inches. The following winter had the all-time record snowfall as 172.9 inches fell for the 2007-08 season. In 2009, August was wet, but September and October were drier than normal. In December of 2008, we had a whopping 87.4 inches with 24.7 inches of snow in January of 2009.

The same pattern continued in 2010, 2011 and 2012. However, in 2013, we had a wet August and September. The overall snow for the 2013-14 season ended up slightly below average in Coeur d’Alene. In 2015, August and September were very dry and the following December had 37.2 inches of snow. The same two months had below-normal rainfall once again in 2017. Then, we had a good snowy month in December as 32.9 inches fell. February of 2018 also had a lot of snow with 30.9 inches.

The summer of 2018 was another dry season, which carried over into September. Snowfalls in December and January were below normal, but a record-smashing 56 inches of snow fell in February of 2019. Our dry August and September pattern continued last year and our big snow month was January of 2020 with 34.1 inches.

So, we’re definitely in a pattern of extreme weather, especially since the turn of the century. Our summers have been generally drier than normal and we’ve had healthy winters in terms of moisture and snowfall across the Inland Northwest. Just based on climatological history alone, our chances of another healthy snow season are looking very good.

In addition to historical patterns, there are other factors that will favor a lot of moisture for the upcoming winter season. According to U.S. Climate Prediction Center and the Bureau of Meteorology in Australia, we now officially have a La Nina, the cooler-than-normal sea-surface temperature event in the waters of the south-central Pacific Ocean. Pacific waters are also warmer than normal in the Gulf of Alaska. This could help increase the moisture in the Northwest in the coming months.

Another indicator that we look at are the number of sunspots. Over the last few years, sunspot activity has been minimal. In fact, there has not been any storms on the sun (sunspots) in early October, so solar activity continues to be very low.

As Cliff and I have been saying, in order to have a record snowy year in Coeur d’Alene and surrounding regions, we need at least a moderate La Nina and very little sunspot activity. Right now, the La Nina is weak, but could get stronger in the next month or two. Last year, ocean waters were too warm, but we still had low sunspot activity. Our final snowfall total last season was an above-normal 96.4 inches.

Many forecasters are predicting a wet and snowy winter across the Northwest. The odds are certainly in our favor for another season with over 100 inches of snow in Coeur d’Alene. Could we see a record-breaking snowy season? As usual, only time will tell and Mother Nature always has the final say.