Winter has certainly arrived across North Idaho and the rest of the Pacific Northwest. As of Sunday afternnon, Cliff had measured over 13 inches of snow for February, with more expected later this week. Our original snowfall projection was about 50 inches for this season. It’s quite possible that we could end up close to 60 inches of snow as this cold and snowy weather pattern is expected to persist through at least the end of the month.
While February is expected to be our snowiest month of the season in North Idaho, we don’t think it will break any records. The snowiest February occurred in 1955 with 39.5 inches. In the mountains, approximately 200 inches of snow has fallen for the season at Silver Mountain.
Last Friday, 7.2 inches of snow blanketed the region. In Seattle, 7.9 inches of snow fell last Friday which is about an inch more than the city normally receives for an entire season. Much of western Washington picked up 6 to 10 inches of snow with Portland seeing around 4 inches.
For many years, we’ve been talking about the fluctuation of sea-surface temperatures and the effects of local and global weather patterns. Since late last year, forecasters have been talking about the warming of the Pacific Ocean that would likely lead to the development of a new El Nino, the abnormal warming of ocean temperatures.
In 2015, we had one of the stronger El Nino events in recorded history. As Cliff and I have mentioned for a long time, when there is an El Nino, Coeur d’Alene and surrounding regions often receive less snow than normal. For the 2015-16 season only 56.2 inches of snow was measured, with most of it falling in December of 2015 as Cliff reported 37.2 inches.
In late 2016, a weak La Nina, the cooler-than-normal sea-surface temperature event, developed in the Pacific Ocean. As a result, Coeur d’Alene received about 115 inches of snowfall for the 2016-17 season, which was the fourth time in less than 10 years that we’ve received more than 100 inches in a single season.
According to the climate scientists, the La Nina in late 2016 was one of the weakest and shortest on record. However, despite the weak event, parts of the Northern Hemisphere experienced some of the coldest, and in some cases, snowiest winter in many years. Other areas of the world had snow and cold temperatures as well.
For the 2017-18 season, we had a weak La Nina and our final snowfall total was around 90 inches, compared to the normal of 69.8 inches.
As of early February, we continue to officially be in a La Nada, the in-between cooler-than-normal sea-surface temperature event, La Nina, and the warmer El Nino.
The latest forecasts from the Australian Bureau of Meteorology suggest there is no immediate risk of a new El Nino. However, forecasters indicate that there is better than a 50 percent chance that an El Nino will develop later this year. According to the U.S. Climate Prediction Center, the majority of the computer models that track sea-surface temperatures are still indicating at least a 65 percent chance of the formation of a weak El Nino during the spring season.
During this pattern of wide weather “extremes,” there have been El Ninos forming about every 2 to 5 years. Very strong El Nino patterns have been occurring about every 15 years. Over the last 20 years, we’ve seen rapid changes in sea-surface temperatures from the warm to cold in relatively short periods of time.
With the warmer ocean waters during the first half of the winter season, most valley locations in North Idaho were receiving more rain than snow as the air mass was too warm. However, as the waters in the Pacific Ocean cooled a bit early this year, we’re now experiencing the coldest weather of the winter season along with increased snowfalls in Coeur d’Alene and surrounding locations.
We’ve also seen a more typical El Nino pattern in California. For example, in Southern California, a series of strong storms pushed moisture totals to above normal levels.
At the Los Angeles International Airport, as of the weekend, approximately 11.75 inches of rain has fallen since Oct. 1, 2018. The normal to date is 7 inches. Last year, in early February of 2018, the region was suffering from severe drought as only 1.51 inches was measured.
The recent cooling of the ocean waters may have also contributed to the massive Arctic outbreak that sent temperatures down to minus 50 degrees across parts of the northern U.S. in late January. Now, North Idaho is feeling some of that frigid weather as the cold air moved westward.
Cliff and I believe that precipitation totals will be above normal in February, March and early April across North Idaho. Then, we do see drier conditions arriving in May and June.
Contact Randy Mann at firstname.lastname@example.org